02559nas a2200301 4500008004100000245008000041210006900121260001200190300001200202490000700214520166000221653001501881653001601896653002901912653001801941653001201959100002901971700001802000700002202018700002002040700002202060700001202082700001602094700002602110700002102136700003302157856006702190 2024 eng d00aSentinel protist taxa of the McMurdo Dry Valley lakes, Antarctica: A review0 aSentinel protist taxa of the McMurdo Dry Valley lakes Antarctica c03/2024 a13234720 v123 a

High-latitude meromictic lakes such as those in the Antarctic McMurdo Dry Valleys (MDV) harbor aquatic ecosystems dominated by the microbial loop. Within this habitat, which is limited year-round by light and nutrients, protists, or single celled eukaryotes, play outsized roles in the food web as the dominant primary producers and the apex predators. Thus, the MDV lake ecosystem represents an ideal system to study the role of sentinel protist taxa in carbon and nutrient cycling. The perennially ice-covered lakes are part of the McMurdo Long Term Ecological Research (McM LTER; mcmlter.org) established in 1993. In this review we will highlight the diversity and trophic roles of the MDV lake protist community and compare environmental factors driving spatiotemporal patterns in key protist taxa in two lakes within the McM LTER, Lakes Bonney and Fryxell. We will then discuss lessons learned from manipulated experiments on the impact of current and future climate-driven environmental change on sensitive protist taxa. Last, we will integrate knowledge gained from 25 years of lab-controlled experiments on key photosynthetic protists to extend our understanding of the function of these extremophiles within the MDV aquatic food webs. Our research group has studied the distribution and function of the MDV microbial community for nearly two decades, training the next generation of scientists to tackle future problems of these globally significant microbes. This review article will also highlight early career scientists who have contributed to this body of work and represent the future of scientific understanding in the Anthropocene.

10aAntarctica10aDisturbance10aMcMurdo Dry Valley lakes10aphytoplankton10aprotist1 aMorgan-Kiss, Rachael, M.1 aPopson, Devon1 aPereira, Rochelle1 aDolhi-Binder, J1 aTeufel, Amber, G.1 aLi, Wei1 aKalra, Isha1 aSherwell, Shasten, S.1 aReynebeau, Emily1 aTakacs-Vesbach, Cristina, D. uhttps://www.frontiersin.org/articles/10.3389/fevo.2024.132347202505nas a2200325 4500008004100000022001400041245012700055210006900182260001200251300001800263490000800281520146500289653001701754653003701771653002401808653002401832100002701856700002101883700002301904700002201927700002201949700002501971700002001996700002202016700002202038700002202060700002202082700001402104856006102118 2023 eng d a2169-900300aCauses and characteristics of electrical resistivity variability in shallow (<4 m) soils in Taylor Valley, East Antarctica0 aCauses and characteristics of electrical resistivity variability c02/2023 ae2022JF0066960 v1283 a

Airborne electromagnetic surveys collected in December 2011 and November 2018 and three soil sampling transects were used to analyze the spatial heterogeneity of shallow (<4 m) soil properties in lower Taylor Valley (TV), East Antarctica. Soil resistivities from 2011 to 2018 ranged from ∼33 Ωm to ∼3,500 Ωm with 200 Ωm assigned as an upper boundary for brine-saturated sediments. Elevations below ∼50 m above sea level (masl) typically exhibit the lowest resistivities with resistivity increasing at high elevations on steeper slopes. Soil water content was empirically estimated from electrical resistivities using Archie's Law and range from ∼<1% to ∼68% by volume. An increase in silt- and clay-sized particles at low elevations increases soil porosity but decreases hydraulic conductivity, promoting greater residence times of soil water at low elevations near Lake Fryxell. Soil resistivity variability between 2011 and 2018 shows soils at different stages of soil freeze-thaw cycles, which are caused predominantly by solar warming of soils as opposed to air temperature. This study furthers the understanding of the hydrogeologic structure of the shallow subsurface in TV and identifies locations of soils that are potentially prone to greater rates of thaw and resulting ecosystem homogenization of soil properties from projected increases in hydrological connectivity across the region over the coming decades.

10aactive layer10aairborne electromagnetic surveys10aMcMurdo Dry Valleys10apermafrost dynamics1 aGutterman, William, S.1 aDoran, Peter, T.1 aVirginia, Ross, A.1 aBarrett, John, E.1 aMyers, Krista, F.1 aTulaczyk, Slawek, M.1 aFoley, Neil, T.1 aMikucki, Jill, A.1 aDugan, Hilary, A.1 aGrombacher, Denys1 aBording, Thue, S.1 aAuken, E. uhttps://onlinelibrary.wiley.com/doi/10.1029/2022JF00669600724nas a2200229 4500008004100000022001400041245005500055210005100110260001200161300000800173490000700181653001200188653001200200653001600212653001600228653001200244100002100256700002200277700002700299700002000326856014800346 2023 eng d a0954-102000aExtreme cold (-69.1°C) in the McMurdo Dry Valleys0 aExtreme cold 691°C in the McMurdo Dry Valleys c03/2023 a1-40 v3010aclimate10aextreme10ameteorology10atemperature10aweather1 aDoran, Peter, T.1 aMyers, Krista, F.1 aMcKay, Christopher, P.1 aBromwich, David uhttps://www.cambridge.org/core/journals/antarctic-science/article/extreme-cold-691c-in-the-mcmurdo-dry-valleys/3516874750E5EF96365A26E8D49CA4EC02591nas a2200229 4500008004100000245013200041210006900173260001200242300000600254490000600260520183600266100002102102700002402123700001802147700001602165700002202181700002402203700003302227700002402260700002202284856005502306 2023 eng d00aImpact of meltwater flow intensity on the spatiotemporal heterogeneity of microbial mats in the McMurdo Dry Valleys, Antarctica0 aImpact of meltwater flow intensity on the spatiotemporal heterog c01/2023 a30 v33 a

The meltwater streams of the McMurdo Dry Valleys are hot spots of biological diversity in the climate-sensitive polar desert landscape. Microbial mats, largely comprised of cyanobacteria, dominate the streams which flow for a brief window of time (~10 weeks) over the austral summer. These communities, critical to nutrient and carbon cycling, display previously uncharacterized patterns of rapid destabilization and recovery upon exposure to variable and physiologically detrimental conditions. Here, we characterize changes in biodiversity, transcriptional responses and activity of microbial mats in response to hydrological disturbance over spatiotemporal gradients. While diverse metabolic strategies persist between marginal mats and main channel mats, data collected from 4 time points during the austral summer revealed a homogenization of the mat communities during the mid-season peak meltwater flow, directly influencing the biogeochemical roles of this stream ecosystem. Gene expression pattern analyses identified strong functional sensitivities of nitrogen-fixing marginal mats to changes in hydrological activities. Stress response markers detailed the environmental challenges of each microhabitat and the molecular mechanisms underpinning survival in a polar desert ecosystem at the forefront of climate change. At mid and end points in the flow cycle, mobile genetic elements were upregulated across all mat types indicating high degrees of genome evolvability and transcriptional synchronies. Additionally, we identified novel antifreeze activity in the stream microbial mats indicating the presence of ice-binding proteins (IBPs). Cumulatively, these data provide a new view of active intra-stream diversity, biotic interactions and alterations in ecosystem function over a high-flow hydrological regime.

1 aZoumplis, Angela1 aKolody, Bethany, C.1 aKaul, Drishti1 aZheng, Hong1 aVenepally, Pratap1 aMcKnight, Diane, M.1 aTakacs-Vesbach, Cristina, D.1 aDeVries, Arthur, L.1 aAllen, Andrew, E. uhttps://www.nature.com/articles/s43705-022-00202-802814nas a2200373 4500008004100000022001400041245010900055210006900164260001200233520170200245653002001947653001001967653001101977653001201988653001102000653001102011100002502022700001902047700001902066700001702085700002102102700002302123700002402146700002502170700002402195700002602219700002102245700002202266700002202288700002102310700001802331700002202349856006902371 2023 eng d a0886-623600aLong-term changes in concentration and yield of riverine dissolved silicon from the poles to the tropics0 aLongterm changes in concentration and yield of riverine dissolve c08/20233 a

Riverine exports of silicon (Si) influence global carbon cycling through the growth of marine diatoms, which account for ∼25% of global primary production. Climate change will likely alter river Si exports in biome-specific ways due to interacting shifts in chemical weathering rates, hydrologic connectivity, and metabolic processes in aquatic and terrestrial systems. Nonetheless, factors driving long-term changes in Si exports remain unexplored at local, regional, and global scales. We evaluated how concentrations and yields of dissolved Si (DSi) changed over the last several decades of rapid climate warming using long-term datasets from 60 rivers and streams spanning the globe (e.g., Antarctic, tropical, temperate, boreal, alpine, Arctic systems). We show that widespread changes in river DSi concentration and yield have occurred, with the most substantial shifts occurring in alpine and polar regions. The magnitude and direction of trends varied within and among biomes, were most strongly associated with differences in land cover, and were often independent of changes in river discharge. These findings indicate that there are likely diverse mechanisms driving change in river Si biogeochemistry that span the land-water interface, which may include glacial melt, changes in terrestrial vegetation, and river productivity. Finally, trends were often stronger in months outside of the growing season, particularly in temperate and boreal systems, demonstrating a potentially important role of shifting seasonality for the flux of Si from rivers. Our results have implications for the timing and magnitude of silica processing in rivers and its delivery to global oceans.

10abiogeochemistry10ariver10asilica10asilicon10astream10atrends1 aJankowski, Kathi, Jo1 aJohnson, Keira1 aSethna, Lienne1 aJulian, Paul1 aWymore, Adam, S.1 aShogren, Arial, J.1 aThomas, Patrick, K.1 aSullivan, Pamela, L.1 aMcKnight, Diane, M.1 aMcDowell, William, H.1 aHeindel, Ruth, C1 aJones, Jeremy, B.1 aWollheim, Wilfred1 aAbbott, Benjamin1 aDeegan, Linda1 aCarey, Joanna, C. uhttps://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GB00767801851nas a2200229 4500008004100000022001400041245013100055210006900186260001200255300001400267490000600281520108300287100002201370700001801392700002501410700002201435700001801457700002701475700002101502700002501523856007301548 2023 eng d a2378-224200aMacroSheds: A synthesis of long-term biogeochemical, hydroclimatic, and geospatial data from small watershed ecosystem studies0 aMacroSheds A synthesis of longterm biogeochemical hydroclimatic  c06/2023 a419 - 4520 v83 a

The US Federal Government supports hundreds of watershed monitoring efforts from which solute fluxes can be calculated. Although instrumentation and methods vary between studies, the data collected and their motivating questions are remarkably similar. Nevertheless, little effort toward their compilation has previously been made. The MacroSheds project has developed a future-friendly system for harmonizing daily time series of streamflow, precipitation, and solute chemistry from 169+ watersheds, and supplementing each with watershed attributes. Here, we describe the breadth of MacroSheds data, and detail the steps involved in rendering each data product. We provide recommendations for usage and discuss when other datasets might be more suitable. The MacroSheds dataset is an unprecedented resource for watershed science, and for hydrology, as a small-watershed supplement to existing collections of streamflow predictors, like CAMELS and GAGES-II. The MacroSheds platform includes a web dashboard for visualization and an R package for data access and analysis.

1 aVlah, Michael, J.1 aRhea, Spencer1 aBernhardt, Emily, S.1 aSlaughter, Weston1 aGubbins, Nick1 aDelVecchia, Amanda, G.1 aThellman, Audrey1 aRoss, Matthew, R. V. uhttps://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lol2.1032502238nas a2200205 4500008004100000245004700041210004700088260004800135490001000183520164300193653001501836653002901851653002201880653001901902653001001921653001001931100002601941700001701967856004801984 2023 eng d00aMicrobial life in challenging environments0 aMicrobial life in challenging environments aBoulder, CObUniversity of Colorado Boulder0 vPh.D.3 a

Microorganisms are nearly ubiquitous on Earth, but the identity and function of microbial communities are inherently dependent on the properties of the specific environment in question. Here, I have studied soils around the world to answer questions about how the functional attributes of microorganisms allow them to respond to challenging environmental conditions. First, I explore how microbial communities in soils change across environmental gradients in Antarctica. I show that microbes in Antarctic surface soils are most restricted by low temperatures, low water availability, and high concentrations of salt. Microbial communities near the polar plateau, the most challenging environment, are dominated by Actinobacteria and Chloroflexi, and are enriched in genes associated with the oxidation of hydrogen gas as an energy source. Second, I show that the earliest microbial colonizers of a newly-formed volcanic island in the Kingdom of Tonga are chemolithotrophs that appear to have come from nearby geothermal systems. While many of these microbes utilize sulfur as an energy source, the most abundant organisms have genes that indicate they can oxidize trace gases including carbon monoxide and hydrogen. Finally, I show that organisms associated with carbon limited subsurface soils tend to have smaller genomes, grow more slowly, and have more gene pathways associated with metabolism and the storage of carbon. Taken together, these studies shed light on microbial survival in challenging soil environments and show the varied ways in which microbial communities interact with and are affected by their surroundings.

10aAntarctica10aenvironmental conditions10amicrobial ecology10amicroorganisms10asoils10atonga1 aDragone, Nicholas, B.1 aFierer, Noah uhttps://www.proquest.com/docview/281473420901629nas a2200217 4500008004100000022001400041245007400055210006900129260001200198300001200210490000600222520097000228100002101198700002201219700002401241700001901265700002101284700002101305700001701326856006801343 2022 eng d a2378-224200aBarotropic seiches in a perennially ice-covered lake, East Antarctica0 aBarotropic seiches in a perennially icecovered lake East Antarct c02/2022 a26 - 330 v73 a

Water movement in ice-covered lakes is known to be driven by wind, sediment heat flux, solar radiation, saline density flows, and advective stream discharge. In large ice-covered lakes, wind-induced oscillations have been found to play a major role in horizontal flows. Here, we report recurrent, wind-driven, barotropic seiches in a small lake with a thick (4 m) permanent ice-cover. Between 2010 and 2016, we recorded 10.5- to 13-min oscillations of the hydrostatic water level in Lake Hoare, McMurdo Dry Valleys, East Antarctica, using pressure transducers moored to the lake bottom and suspended from the ice cover. Theoretical calculations showed a barotropic seiche should have a period of 12.6 min. Barotropic seiches were most frequent during high wind events (> 5 m s-1) in winter months (February–November). The period increased during summer months (December–January) when fast ice thinned and melted along the shoreline.

1 aCastendyk, Devin1 aDugan, Hilary, A.1 aGallagher, Hugh, A.1 aPujara, Nimish1 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry uhttps://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lol2.1022602219nas a2200349 4500008004100000022001400041245012300055210006900178260001200247520113200259653000901391653001901400653001601419653001201435653000901447653001301456100002001469700002501489700001601514700002501530700002101555700001701576700002501593700002501618700002101643700002501664700002601689700002201715700002301737700001801760856009101778 2022 eng d a0006-356800aCross-site comparisons of dryland ecosystem response to climate change in the US Long-Term Ecological Research Network0 aCrosssite comparisons of dryland ecosystem response to climate c c08/20223 a

Long-term observations and experiments in diverse drylands reveal how ecosystems and services are responding to climate change. To develop generalities about climate change impacts at dryland sites, we compared broadscale patterns in climate and synthesized primary production responses among the eight terrestrial, nonforested sites of the United States Long-Term Ecological Research (US LTER) Network located in temperate (Southwest and Midwest) and polar (Arctic and Antarctic) regions. All sites experienced warming in recent decades, whereas drought varied regionally with multidecadal phases. Multiple years of wet or dry conditions had larger effects than single years on primary production. Droughts, floods, and wildfires altered resource availability and restructured plant communities, with greater impacts on primary production than warming alone. During severe regional droughts, air pollution from wildfire and dust events peaked. Studies at US LTER drylands over more than 40 years demonstrate reciprocal links and feedbacks among dryland ecosystems, climate-driven disturbance events, and climate change.

10aANPP10aclimate change10aDisturbance10adrought10aLTER10awildfire1 aHudson, Amy, R.1 aPeters, Debra, P. C.1 aBlair, J.M.1 aChilders, Daniel, L.1 aDoran, Peter, T.1 aGeil, Kerrie1 aGooseff, Michael, N.1 aGross, Katherine, L.1 aHaddad, Nick, M.1 aPastore, Melissa, A.1 aRudgers, Jennifer, A.1 aSala, Osvaldo, E.1 aSeabloom, Eric, W.1 aShaver, Gaius uhttps://academic.oup.com/bioscience/advance-article/doi/10.1093/biosci/biab134/665484002454nas a2200277 4500008004100000245020000041210006900241260001200310300001400322490000800336520152000344653001501864653001401879653002501893653001801918653001701936653000801953100002401961700001601985700002102001700001902022700001802041700002302059700002902082856006502111 2022 eng d00aCyclic electron flow (CEF) and ascorbate pathway activity provide constitutive photoprotection for the photopsychrophile, Chlamydomonas sp. UWO 241 (renamed Chlamydomonas priscuii)0 aCyclic electron flow CEF and ascorbate pathway activity provide  c03/2022 a235 - 2500 v1513 a

Under environmental stress, plants and algae employ a variety of strategies to protect the photosynthetic apparatus and maintain photostasis. To date, most studies on stress acclimation have focused on model organisms which possess limited to no tolerance to stressful extremes. We studied the ability of the Antarctic alga Chlamydomonas sp. UWO 241 (UWO 241) to acclimate to low temperature, high salinity or high light. UWO 241 maintained robust growth and photosynthetic activity at levels of temperature (2 °C) and salinity (700 mM NaCl) which were nonpermissive for a mesophilic sister species, Chlamydomonas raudensis SAG 49.72 (SAG 49.72). Acclimation in the mesophile involved classic mechanisms, including downregulation of light harvesting and shifts in excitation energy between photosystem I and II. In contrast, UWO 241 exhibited high rates of PSI-driven cyclic electron flow (CEF) and a larger capacity for nonphotochemical quenching (NPQ). Furthermore, UWO 241 exhibited constitutively high activity of two key ascorbate cycle enzymes, ascorbate peroxidase and glutathione reductase and maintained a large ascorbate pool. These results matched the ability of the psychrophile to maintain low ROS under short-term photoinhibition conditions. We conclude that tight control over photostasis and ROS levels are essential for photosynthetic life to flourish in a native habitat of permanent photooxidative stress. We propose to rename this organism Chlamydomonas priscuii.

10aAntarctica10aascorbate10aCyclic electron flow10aPhotosystem I10aPsychrophile10aROS1 aStahl-Rommel, Sarah1 aKalra, Isha1 aD'Silva, Susanna1 aHahn, Mark, M.1 aPopson, Devon1 aCvetkovska, Marina1 aMorgan-Kiss, Rachael, M. uhttps://link.springer.com/article/10.1007/s11120-021-00877-500974nas a2200217 4500008004100000245004900041210004200090260001200132490000700144520034200151653001500493653001700508653001300525653002500538653001000563653001400573100001300587700002100600700002200621856011300643 2022 eng d00aA draft mitogenome of Plectus murrayi0 adraft mitogenome of iPlectus murrayii c02/20220 v543 a

Plectus murrayi is a free-living microbivorous nematode endemic to Antarctic soils. Our draft assembly of its mitogenome was 15,656 bp long, containing 12 protein-coding, eight transfer RNA (tRNA), and two ribosomal RNA (rRNA) genes. Mitophylogenomic analyses extend our understanding of mitochondrial evolution in Nematoda

10aAntarctica10agenome decay10agenomics10amitochondrial genome10aMitoZ10aphylogeny1 aXue, Xia1 aAdams, Byron, J.1 aDilman, Adler, R. uhttps://www.sciendo.com/article/10.2478/jofnem-2022-0035https://www.sciendo.com/pdf/10.2478/jofnem-2022-003502367nas a2200289 4500008004100000245011400041210006900155260001200224300001400236490000600250520147700256653001501733653002201748653002201770653001001792100002601802700002401828700002701852700002101879700001801900700001701918700002001935700001701955700001701972700002401989856006402013 2022 eng d00aElevational constraints on the composition and genomic attributes of microbial communities in Antarctic soils0 aElevational constraints on the composition and genomic attribute c01/2022 ae01330-210 v73 a

The inland soils found on the Antarctic continent represent one of the more challenging environments for microbial life on Earth. Nevertheless, Antarctic soils harbor unique bacterial and archaeal (prokaryotic) communities able to cope with extremely cold and dry conditions. These communities are not homogeneous, and the taxonomic composition and functional capabilities (genomic attributes) of these communities across environmental gradients remain largely undetermined. We analyzed the prokaryotic communities in soil samples collected from across the Shackleton Glacier region of Antarctica by coupling quantitative PCR, marker gene amplicon sequencing, and shotgun metagenomic sequencing. We found that elevation was the dominant factor explaining differences in the structures of the soil prokaryotic communities, with the drier and saltier soils found at higher elevations harboring less diverse communities and unique assemblages of cooccurring taxa. The higher-elevation soil communities also had lower maximum potential growth rates (as inferred from metagenome-based estimates of codon usage bias) and an overrepresentation of genes associated with trace gas metabolism. Together, these results highlight the utility of assessing community shifts across pronounced environmental gradients to improve our understanding of the microbial diversity found in Antarctic soils and the strategies used by soil microbes to persist at the limits of habitability.

10aAntarctica10amicrobial ecology10asoil microbiology10asoils1 aDragone, Nicholas, B.1 aHenley, Jessica, B.1 aHolland-Moritz, Hannah1 aDiaz, Melisa, A.1 aHogg, Ian, D.1 aLyons, Berry1 aWall, Diana, H.1 aAdams, Byron1 aFierer, Noah1 aMackelprang, Rachel uhttps://journals.asm.org/doi/full/10.1128/msystems.01330-2101993nas a2200253 4500008004100000022001400041245010200055210006900157260001200226300001100238490000700249520122000256653001501476653000901491653002401500653002201524653001701546653002301563100002501586700002401611700002101635700002101656856006201677 2022 eng d a0885-608700aLong-term stream hydrology and meteorology of a polar desert, the McMurdo Dry Valleys, Antarctica0 aLongterm stream hydrology and meteorology of a polar desert the  c06/2022 ae146230 v363 a

The McMurdo Dry Valleys (MDVs; 77.50°S, 162.25°E) make up the largest ice-free region of Antarctica at 3500 km2. Their position near the coast of the Ross Sea provides for a milder climate than much of the rest of the continent. Alpine and piedmont glaciers in the MDVs melt during the austral summer providing water to down gradient streams and terminal lakes on valley floors. There are currently 14 meteorological stations and 17 stream gauges operating across the MDVs, some with continuous records that go back to 1969. This relatively high density of monitoring stations reflects the fact that glaciers of different sizes and elevation ranges are the main source of water to streams. Thus, each glacier represents a different watershed. The bulk of these records start in the late 1980s/early 1990s. These data collection activities directly support research endeavors of the McMurdo Dry Valleys Long Term Ecological Research project, as well as a host of other science groups working in the MDVs. As such, both real time data and archived data from these sites is available through the online database interface of the project (https://mcmlter.org).

10aAntarctica10aLTER10aMcMurdo Dry Valleys10ameltwater streams10apolar desert10aresearch catchment1 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aDoran, Peter, T.1 aFountain, Andrew uhttps://onlinelibrary.wiley.com/doi/abs/10.1002/hyp.1462302944nas a2200301 4500008004100000022001400041245009600055210007100151260001200222490000700234520204100241653001702282653001902299653002002318653001402338653002302352653002302375100002602398700001702424700002102441700002402462700002602486700001702512700001702529700001802546700002002564856005802584 2022 eng d a1354-101300aResponse of Antarctic soil fauna to climate‐driven changes since the Last Glacial Maximum0 aResponse of Antarctic soil fauna to climate‐driven changes since c01/20220 v283 a

Understanding how terrestrial biotic communities have responded to glacial recession since the Last Glacial Maximum (LGM) can inform present and future responses of biota to climate change. In Antarctica, the Transantarctic Mountains (TAM) have experienced massive environmental changes associated with glacial retreat since the LGM, yet we have few clues as to how its soil invertebrate-dominated animal communities have responded. Here, we surveyed soil invertebrate fauna from above and below proposed LGM elevations along transects located at 12 features across the Shackleton Glacier region. Our transects captured gradients of surface ages possibly up to 4.5 million years and the soils have been free from human disturbance for their entire history. Our data support the hypothesis that soils exposed during the LGM are now less suitable habitats for invertebrates than those that have been exposed by deglaciation following the LGM. Our results show that faunal abundance, community composition, and diversity were all strongly affected by climate-driven changes since the LGM. Soils more recently exposed by glacial recession (as indicated by distances from present ice surfaces) had higher faunal abundances and species richness than older exposed soils. Higher abundances of the dominant nematode Scottnema were found in older exposed soils, while Eudorylaimus, Plectus, tardigrades, and rotifers preferentially occurred in more recently exposed soils. Approximately 30% of the soils from which invertebrates could be extracted had only Scottnema, and these single-taxon communities occurred more frequently in soils exposed for longer periods of time. Our structural equation modeling of abiotic drivers highlighted soil salinity as a key mediator of Scottnema responses to soil exposure age. These changes in soil habitat suitability and biotic communities since the LGM indicate that Antarctic terrestrial biodiversity throughout the TAM will be highly altered by climate warming.

10abiodiversity10aclimate change10aglacial retreat10anematodes10aShackleton Glacier10asoil invertebrates1 aFranco, André, L. C.1 aAdams, Byron1 aDiaz, Melisa, A.1 aLemoine, Nathan, P.1 aDragone, Nicholas, B.1 aFierer, Noah1 aLyons, Berry1 aHogg, Ian, D.1 aWall, Diana, H. uhttps://onlinelibrary.wiley.com/doi/10.1111/gcb.1594002575nas a2200397 4500008004100000022001400041245006100055210005700116260001200173490000800185520139000193100002701583700002801610700001701638700002401655700003001679700001901709700002201728700002101750700002301771700002201794700002501816700002001841700002201861700002101883700002201904700003101926700002201957700002301979700002202002700002402024700002102048700002202069700003302091856005302124 2022 eng d a0027-842400aThe time is right for an Antarctic biorepository network0 atime is right for an Antarctic biorepository network c12/20220 v1193 a

Antarctica is a central driver of the Earth’s climate and health. The Southern Ocean surrounding Antarctica serves as a major sink for anthropogenic CO2 and heat, and the loss of Antarctic ice sheets contributes significantly to sea level rise and will continue to do so as the loss of ice sheets accelerates, with sufficient water stores to raise sea levels by 58 m. Antarctica's marine environment is home to a number of iconic species, and the terrestrial realm harbors a remarkable oasis for life, much of which has yet to be discovered. Distinctive oceanographic features of the Southern Ocean—including the Antarctic Circumpolar Current, the Antarctic Polar Front, and exceptional depths surrounding the continent—coupled with chronically cold temperatures have fostered the evolution of a vast number of uniquely coldadapted species, many of which are found nowhere else on the Earth. The Antarctic marine biota, for example, displays the highest level of species endemism on the Earth. However, warming, ocean acidification, pollution, and commercial exploitation threaten the integrity of Antarctic ecosystems. Understanding changes in the biota and its capacities for adaptation is imperative for establishing effective policies for mitigating the impacts of climate change and sustaining the Antarctic ecosystems that are vital to global health.

1 aO’Brien, Kristin, M.1 aCrockett, Elizabeth, L.1 aAdams, Byron1 aAmsler, Charles, D.1 aAppiah-Madson, Hannah, J.1 aCollins, Allen1 aDesvignes, Thomas1 aDetrich, William1 aDistel, Daniel, L.1 aEppley, Sarah, M.1 aFrable, Benjamin, W.1 aFranz, Nico, M.1 aGrim, Jeffrey, M.1 aKocot, Kevin, M.1 aMahon, Andrew, R.1 aMayfield-Meyer, Teresa, J.1 aMikucki, Jill, A.1 aMoser, William, E.1 aSchmull, Michaela1 aSeid, Charlotte, A.1 aSmith, Craig, R.1 aTodgham, Anne, E.1 aWatkins-Colwell, Gregory, J. uhttps://www.pnas.org/doi/10.1073/pnas.221280011901961nas a2200217 4500008004100000245010100041210006900142260001200211300001200223490000700235520124400242653003001486653001101516653002401527653001501551653002101566100002001587700002101607700002201628856009301650 2022 eng d00aValley-floor snowfall in Taylor Valley, Antarctica, from 1995 to 2017: Spring, summer and autumn0 aValleyfloor snowfall in Taylor Valley Antarctica from 1995 to 20 c08/2022 a325-3350 v343 a

We present an analysis of the 20 year snowfall dataset in Taylor Valley and the results of a new snow cover monitoring study. Snowfall has been measured at four sites in Taylor Valley from 1995 to 2017. We focus on valley-floor snowfall when wind does not exceed 5 m s-1, and we exclude winter from our analysis due to poor data quality. Snowfall averaged 11 mm water equivalent (w.e.) from 1995 to 2017 across all stations and ranged from 1 to 58 mm w.e. Standard deviations ranged from 3 to 17 mm w.e., highlighting the strong interannual variability of snowfall in Taylor Valley. During spring and autumn there is a spatial gradient in snowfall such that the coast received twice as much snowfall as more central and inland stations. We identified a changepoint in 2007 from increasing snowfall (3 mm w.e. yr-1) to decreasing snowfall (1 mm w.e. yr-1), which coincides with a shift from decreasing temperature to no detectable temperature trend. Daily camera imagery from 2007 to 2017 augments the snowfall measurements. The camera imagery revealed a near tripling of the average number of days with snow cover from 37 days between 2006 and 2012 to 106 days with snow cover between 2012 and 2017.

10aautomated weather station10acamera10aMcMurdo Dry Valleys10asnow cover10asnow persistence1 aMyers, Madeline1 aDoran, Peter, T.1 aMyers, Krista, F. uhttps://www.cambridge.org/core/product/identifier/S0954102022000256/type/journal_article03115nas a2200517 4500008004100000245008300041210006900124260001200193520161800205653001501823653002101838653002601859653001901885653001301904653001701917653002401934653002301958653001701981653001201998100001702010700001802027700002202045700002102067700002002088700003002108700002102138700002402159700002102183700002302204700001502227700001802242700002102260700002302281700002202304700002002326700002302346700002402369700001602393700002302409700002402432700002102456700001902477700001802496700002002514856006302534 2021 eng d00aAntarctic ecosystems in transition – life between stresses and opportunities0 aAntarctic ecosystems in transition life between stresses and opp c06/20213 a

Important findings from the second decade of the 21st century on the impact of environmental change on biological processes in the Antarctic were synthesised by 26 international experts. Ten key messages emerged that have stakeholder‐relevance and/or a high impact for the scientific community. They address (i) altered biogeochemical cycles, (ii) ocean acidification, (iii) climate change hotspots, (iv) unexpected dynamism in seabed‐dwelling populations, (v) spatial range shifts, (vi) adaptation and thermal resilience, (vii) sea ice related biological fluctuations, (viii) pollution, (ix) endangered terrestrial endemism and (x) the discovery of unknown habitats. Most Antarctic biotas are exposed to multiple stresses and considered vulnerable to environmental change due to narrow tolerance ranges, rapid change, projected circumpolar impacts, low potential for timely genetic adaptation, and migration barriers. Important ecosystem functions, such as primary production and energy transfer between trophic levels, have already changed, and biodiversity patterns have shifted. A confidence assessment of the degree of ‘scientific understanding’ revealed an intermediate level for most of the more detailed sub‐messages, indicating that process‐oriented research has been successful in the past decade. Additional efforts are necessary, however, to achieve the level of robustness in scientific knowledge that is required to inform protection measures of the unique Antarctic terrestrial and marine ecosystems, and their contributions to global biodiversity and ecosystem services.

10aadaptation10abenthic dynamism10abiogeochemical cycles10aclimate change10ainvasion10anew habitats10aocean acidification10aPrimary production10arange shifts10asea ice1 aGutt, Julian1 aIsla, Enrique1 aXavier, José, C.1 aAdams, Byron, J.1 aAhn, In‐Young1 aCheng, C.‐H., Christina1 aColesie, Claudia1 aCummings, Vonda, J.1 adi Prisco, Guido1 aGriffiths, Huw, J.1 aHawes, Ian1 aHogg, Ian, D.1 aMcIntyre, Trevor1 aMeiners, Klaus, M.1 aPearce, David, A.1 aPeck, Lloyd, S.1 aPiepenburg, Dieter1 aReisinger, Ryan, R.1 aSaba, Grace1 aSchloss, Irene, R.1 aSignori, Camila, N.1 aSmith, Craig, R.1 aVacchi, Marino1 aVerde, Cinzia1 aWall, Diana, H. uhttps://onlinelibrary.wiley.com/doi/full/10.1111/brv.1267904166nas a2200565 4500008004100000022001400041245007900055210006900134260001200203300001100215490000700226520245300233653001802686653002702704653001902731653001902750653001202769653001202781653001502793653008902808653002002897100002302917700002502940700002602965700002702991700002103018700002503039700001703064700002203081700002903103700002603132700002403158700002603182700002403208700002103232700001603253700002703269700002403296700002303320700002203343700002403365700002303389700001503412700002203427700002103449700002203470700002603492700002403518856005803542 2021 eng d a2150-892500aConnectivity: Insights from the U.S. Long Term Ecological Research Network0 aConnectivity Insights from the US Long Term Ecological Research  c05/2021 ae034320 v123 a

Ecosystems across the United States are changing in complex and surprising ways. Ongoing demand for critical ecosystem services requires an understanding of the populations and communities in these ecosystems in the future. This paper represents a synthesis effort of the U.S. National Science Foundation-funded Long-Term Ecological Research (LTER) network addressing the core research area of “populations and communities.” The objective of this effort was to show the importance of long-term data collection and experiments for addressing the hardest questions in scientific ecology that have significant implications for environmental policy and management. Each LTER site developed at least one compelling case study about what their site could look like in 50–100 yr as human and environmental drivers influencing specific ecosystems change. As the case studies were prepared, five themes emerged, and the studies were grouped into papers in this LTER Futures Special Feature addressing state change, connectivity, resilience, time lags, and cascading effects. This paper addresses the “connectivity” theme and has examples from the Phoenix (urban), Niwot Ridge (alpine tundra), McMurdo Dry Valleys (polar desert), Plum Island (coastal), Santa Barbara Coastal (coastal), and Jornada (arid grassland and shrubland) sites. Connectivity has multiple dimensions, ranging from multi-scalar interactions in space to complex interactions over time that govern the transport of materials and the distribution and movement of organisms. The case studies presented here range widely, showing how land-use legacies interact with climate to alter the structure and function of arid ecosystems and flows of resources and organisms in Antarctic polar desert, alpine, urban, and coastal marine ecosystems. Long-term ecological research demonstrates that connectivity can, in some circumstances, sustain valuable ecosystem functions, such as the persistence of foundation species and their associated biodiversity or, it can be an agent of state change, as when it increases wind and water erosion. Increased connectivity due to warming can also lead to species range expansions or contractions and the introduction of undesirable species. Continued long-term studies are essential for addressing the complexities of connectivity. The diversity of ecosystems within the LTER network is a strong platform for these studies.

10aalpine tundra10aAntarctic polar desert10aarid grassland10aarid shrubland10acoastal10aestuary10asalt marsh10aSpecial Feature: Forecasting Earth’s Ecosystems with Long-Term Ecological Research10aurban ecosystem1 aIwaniec, David, M.1 aGooseff, Michael, N.1 aSuding, Katharine, N.1 aJohnson, David, Samuel1 aReed, Daniel, C.1 aPeters, Debra, P. C.1 aAdams, Byron1 aBarrett, John, E.1 aBestelmeyer, Brandon, T.1 aCastorani, Max, C. N.1 aCook, Elizabeth, M.1 aDavidson, Melissa, J.1 aGroffman, Peter, M.1 aHanan, Niall, P.1 aHuenneke, L1 aJohnson, Pieter, T. J.1 aMcKnight, Diane, M.1 aMiller, Robert, J.1 aOkin, Gregory, S.1 aPreston, Daniel, L.1 aRassweiler, Andrew1 aRay, Chris1 aSala, Osvaldo, E.1 aSchooley, Robert1 aSeastedt, Timothy1 aSpasojevic, Marko, J.1 aVivoni, Enrique, R. uhttps://onlinelibrary.wiley.com/doi/10.1002/ecs2.343201995nas a2200205 4500008004100000245012000041210006900161260004800230490000900278520132200287653001501609653001101624653001801635653001201653653001501665653001301680100002401693700002401717856004801741 2021 eng d00aControls on microbial mat coverage and diatom species turnover in Antarctic desert streams: A transplant experiment0 aControls on microbial mat coverage and diatom species turnover i aBoulder, CObUniversity of Colorado Boulder0 vM.S.3 a

This thesis evaluates how polar desert streams regulate benthic microbial mat coverage, chlorophyll-a biomass, and diatom species composition. Microbial mats growing on rocks (eplithon) and on sandy substrate (epipelon) were reciprocally transplanted among four glaciers meltwater streams and monitored through time. The selected study streams were Green Creek, Bowles Creek, Delta Stream, Von Guerard Stream in the Lake Fryxell Basin in the McMurdo Dry Valleys, Antarctica. These streams vary in length, streamflow intermittency, and diatom community composition of microbial mats. Results demonstrate that streams strongly control mat biomass (coverage and chlorophyll-a) differently for epilithon and epipelon. However, diatom species composition did not vary between these growth habitats but instead varied by stream, suggesting adaptive niche separation related to environmental conditions. Diatom species composition of transplants in Green Creek became dissimilar from their initial stream communities suggesting downstream dispersal and within stream connectivity regulates community assembly. This experiment confirms that environmental characteristics and intra-stream dispersal processes exert strong control over maintaining microbial mat coverage, biomass accrual, and diatom species composition.

10aAntarctica10adiatom10amicrobial mat10astreams10atransplant10aturnover1 aDarling, Joshua, P.1 aMcKnight, Diane, M. uhttps://www.proquest.com/docview/263459098202809nas a2200337 4500008004100000245012000041210006900161260001200230300001800242490000800260520168500268653002201953653002001975653004901995653001902044653001202063653004302075653001902118653002402137653002102161653003102182100002102213700002402234700002202258700002402280700002402304700002502328700002402353700002502377856006902402 2021 eng d00aDiatoms in hyporheic sediments trace organic matter retention and processing in the McMurdo Dry Valleys, Antarctica0 aDiatoms in hyporheic sediments trace organic matter retention an c02/2021 ae2020JG0060970 v1263 a

In low‐nutrient streams in cold and arid ecosystems, the spiraling of autochthonous particulate organic matter (POM) may provide important nutrient subsidies downstream. Because of its lability and the spatial heterogeneity of processing in hyporheic sediments, the downstream transport and fate of autochthonous POM can be difficult to trace. In Antarctic McMurdo Dry Valley (MDV) streams, any POM retained in the hyporheic zone is expected to be derived from surface microbial mats that contain diatoms with long‐lasting silica frustules. We tested whether diatom frustules can be used to trace the retention of autochthonous POM in the hyporheic zone and whether certain geomorphic locations promote this process. The accumulation of diatom frustules in hyporheic sediments, measured as biogenic silica, was correlated with loss‐on‐ignition organic matter and sorbed ammonium, suggesting that diatoms can be used to identify locations where POM has been retained and processed over long timescales, regardless of whether the POM remains intact. In addition, by modeling the upstream sources of hyporheic diatom assemblages, we found that POM was predominantly derived from N‐fixing microbial mats of the genus Nostoc. In terms of spatial variability, we conclude that the hyporheic sediments adjacent to the stream channel that are regularly inundated by daily flood pulses are where the most POM has been retained over long timescales. Autochthonous POM is retained in hyporheic zones of low‐nutrient streams beyond the MDVs, and we suggest that biogenic silica and diatom composition can be used to identify locations where this transfer is most prevalent.

10abenthic processes10abiogenic silica10abiogeochemical cycles processes and modeling10acarbon cycling10adiatoms10agroundwater/surface water interactions10ahyporheic zone10aMcMurdo Dry Valleys10anitrogen cycling10aparticulate organic matter1 aHeindel, Ruth, C1 aDarling, Joshua, P.1 aSingley, Joel, G.1 aBergstrom, Anna, J.1 aMcKnight, Diane, M.1 aLukkari, Braeden, M.1 aWelch, Kathleen, A.1 aGooseff, Michael, N. uhttps://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JG00609702506nas a2200289 4500008004100000022001400041245006300055210006300118260001200181490000800193520169900201653001501900653001701915653001301932653001801945653001001963653001001973100002601983700002102009700001802030700001702048700002002065700002002085700002102105700001702126856007302143 2021 eng d a2169-895300aExploring the boundaries of microbial habitability in soil0 aExploring the boundaries of microbial habitability in soil c06/20210 v1263 a

Microbes are widely assumed to be capable of colonizing even the most challenging terrestrial surface environments on Earth given enough time. We would not expect to find surface soils uninhabited by microbes as soils typically harbor diverse microbial communities and viable microbes have been detected in soils exposed to even the most inhospitable conditions. However, if uninhabited soils do exist, we might expect to find them in Antarctica. We analyzed 204 ice-free soils collected from across a remote valley in the Transantarctic Mountains (84–85°S, 174–177°W) and were able to identify a potential limit of microbial habitability. While most of the soils we tested contained diverse microbial communities, with fungi being particularly ubiquitous, microbes could not be detected in many of the driest, higher elevation soils—results that were confirmed using cultivation-dependent, cultivation-independent, and metabolic assays. While we cannot confirm that this subset of soils is completely sterile and devoid of microbial life, our results suggest that microbial life is severely restricted in the coldest, driest, and saltiest Antarctic soils. Constant exposure to these conditions for thousands of years has limited microbial communities so that their presence and activity is below detectable limits using a variety of standard methods. Such soils are unlikely to be unique to the studied region with this work supporting previous hypotheses that microbial habitability is constrained by near-continuous exposure to cold, dry, and salty conditions, establishing the environmental conditions that limit microbial life in terrestrial surface soils.

10aAntarctica10aastrobiology10abacteria10aextremophiles10afungi10asoils1 aDragone, Nicholas, B.1 aDiaz, Melisa, A.1 aHogg, Ian, D.1 aLyons, Berry1 aJackson, Andrew1 aWall, Diana, H.1 aAdams, Byron, J.1 aFierer, Noah uhttps://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JG00605201860nas a2200205 4500008004100000022001400041245015300055210006900208260001200277520112000289100002201409700002001431700002001451700002501471700001701496700002401513700002501537700002401562856006801586 2021 eng d a2378-224200aFrom the Heroic Age to today: What diatoms from Shackleton's Nimrod expedition can tell us about the ecological trajectory of Antarctic ponds0 aFrom the Heroic Age to today What diatoms from Shackletons iNimr c07/20213 a

Biological invasion and environmental change pose major threats to ecosystems. While long-term ecological change is commonly evaluated through sediment cores in lakes, it is generally not feasible for smaller ponds, and spatial resolution is limited. Here, we analyze pond diatom communities collected during Shackleton's Nimrod expedition at Cape Royds, Antarctica, to compare with the same waterbodies a century later. We find historical samples to be almost identical to modern counterparts, and provide no evidence of exotic introductions despite increasing human activity. However, a shift occurred in the pond nearest Shackleton's hut, Pony Lake, which was dominated by Luticola muticopsis a century ago, and was replaced by Craspedostauros laevissimus. Both are endemic species previously and currently present at Cape Royds, and we hypothesize that a shift in conductivity accompanying changing precipitation patterns may be responsible. Collectively, these results provide important data for assessing human and climate impacts among Antarctic lacustrine habitats.

1 aKohler, Tyler, J.1 aHowkins, Adrian1 aSokol, Eric, R.1 aKopalová, Kateřina1 aCox, Aneliya1 aDarling, Joshua, P.1 aGooseff, Michael, N.1 aMcKnight, Diane, M. uhttps://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lol2.1020002256nas a2200217 4500008004100000245008600041210006900127260001200196520154900208653001401757653002401771653002001795653001701815653002001832100001301852700001901865700002201884700002201906700001701928856009301945 2021 eng d00aGenome analysis of Plectus murrayi, a nematode from continental Antarctica0 aGenome analysis of IPlectus murrayiI a nematode from continental c01/20213 a

Plectus murrayi is one of the most common and locally abundant invertebrates of continental Antarctic ecosystems. Because it is readily cultured on artificial medium in the laboratory and highly tolerant to an extremely harsh environment, Plectus murrayi is emerging as a model organism for understanding the evolutionary origin and maintenance of adaptive responses to multiple environmental stressors, including freezing and desiccation. The de novo assembled genome of Plectus murrayi contains 225.741 million base pairs and a total of 14,689 predicted genes. Compared to Caenorhabditis elegans, the architectural components of Plectus murrayi are characterized by a lower number of protein-coding genes, fewer transposable elements, but more exons, than closely related taxa from less harsh environments. We compared the transcriptomes of lab-reared Plectus murrayi with wild-caught Plectus murrayi and found genes involved in growth and cellular processing were up-regulated in lab-cultured Plectus murrayi, while a few genes associated with cellular metabolism and freeze tolerance were expressed at relatively lower levels. Preliminary comparative genomic and transcriptomic analyses suggest that the observed constraints on P. murrayi genome architecture and functional gene expression, including genome decay and intron retention, may be an adaptive response to persisting in a biotically simplified, yet consistently physically harsh environment.

10agene loss10agenome architecture10agenome assembly10agenome decay10aPlectus murrayi1 aXue, Xia1 aSuvorov, Anton1 aFujimoto, Stanley1 aDilman, Adler, R.1 aAdams, Byron uhttps://academic.oup.com/g3journal/advance-article/doi/10.1093/g3journal/jkaa045/604418902615nas a2200229 4500008004100000245011400041210006900155260001200224300001600236490000700252520188900259100002102148700002902169700002102198700002002219700002102239700002002260700001802280700001702298700001702315856005302332 2021 eng d00aGeochemical zones and environmental gradients for soils from the central Transantarctic Mountains, Antarctica0 aGeochemical zones and environmental gradients for soils from the c03/2021 a1629 - 16440 v183 a

Previous studies have established links between biodiversity and soil geochemistry in the McMurdo Dry Valleys, Antarctica, where environmental gradients are important determinants of soil biodiversity. However, these gradients are not well established in the central Transantarctic Mountains, which are thought to represent some of the least hospitable Antarctic soils. We analyzed 220 samples from 11 ice-free areas along the Shackleton Glacier (~85°S), a major outlet glacier of the East Antarctic Ice Sheet. We established three zones of distinct geochemical gradients near the head of the glacier (upper), its central part (middle), and at the mouth (lower). The upper zone had the highest water-soluble salt concentrations with total salt concentrations exceeding 80 000 µg g-1, while the lower zone had the lowest water-soluble N:P ratios, suggesting that, in addition to other parameters (such as proximity to water and/or ice), the lower zone likely represents the most favorable ecological habitats. Given the strong dependence of geochemistry on geographic parameters, we developed multiple linear regression and random forest models to predict soil geochemical trends given latitude, longitude, elevation, distance from the coast, distance from the glacier, and soil moisture (variables which can be inferred from remote measurements). Confidence in our random forest model predictions was moderately high with R2 values for total water-soluble salts, water-soluble N:P, ClO4-, and ClO3- of 0.81, 0.88, 0.78, and 0.74, respectively. These modeling results can be used to predict geochemical gradients and estimate salt concentrations for other Transantarctic Mountain soils, information that can ultimately be used to better predict distributions of soil biota in this remote region.

1 aDiaz, Melisa, A.1 aGardner, Christopher, B.1 aWelch, Susan, A.1 aJackson, Andrew1 aAdams, Byron, J.1 aWall, Diana, H.1 aHogg, Ian, D.1 aFierer, Noah1 aLyons, Berry uhttps://bg.copernicus.org/articles/18/1629/2021/02981nas a2200253 4500008004100000022001400041245011200055210006900167260001200236300001400248490000700262520216600269653002102435653002602456653002602482100002802508700002202536700002202558700002102580700002202601700001802623700001502641856007102656 2021 eng d a1523-043000aThe magnitude and climate sensitivity of isotopic fractionation from ablation of Antarctic Dry Valley lakes0 amagnitude and climate sensitivity of isotopic fractionation from c12/2021 a352 - 3710 v533 a

There has been extensive research on the effects of evaporation on the isotopic ratio of lacustrine and marine water bodies; however, there are limited data on how ablation or sublimation from lake or sea ice influences the isotopic ratio of the residual water body. This is a challenging problem because there remains uncertainty on the magnitude of fractionation during sublimation and because ablation can involve mixed-phase processes associated with simultaneous sublimation, melting, evaporation, and refreezing. This uncertainty limits the ability to draw quantitative inferences on changing hydrological budgets from stable isotope records in arctic, Antarctic, and alpine lakes. Here, we use in situ measurements of the isotopic ratio of water vapor along with the gradient diffusion method to constrain the isotopic ratio of the ablating ice from two lakes in the McMurdo Dry Valleys, Antarctica. We find that during austral summer, the isotopic fractionation of ablation was insignificant during periods of boundary layer instability that are typical during midday when latent heat is highest. This implies that the loss of mass during these periods did not yield any isotopic enrichment to the residual lake mass. However, fractionation increased after midday when the boundary layer stabilized and the latent heat flux was small. This diurnal pattern was mirrored on synoptic timescales, when following warm and stable conditions latent heat flux was low and dominated by higher fractionation for a few days. We hypothesize that the shifting from negligible to large isotopic fractionation reflects the development and subsequent exhaustion of liquid water on the surface. The results illustrate the complex and nonlinear controls on isotopic fractionation from icy lakes, which implies that the isotopic enrichment from ablation could vary significantly over timescales relevant for changing lake volumes. Future work using water isotope fluxes for longer periods of time and over additional perennial and seasonal ice-covered lake systems is critical for developing models of the isotopic mass balance of arctic and Antarctic lake systems.

10aDry Valley lakes10aisotope fractionation10astable water isotopes1 aBellagamba, Anthony, W.1 aBerkelhammer, Max1 aWinslow, Luke, A.1 aDoran, Peter, T.1 aMyers, Krista, F.1 aDevlin, Shawn1 aHawes, Ian uhttps://www.tandfonline.com/doi/full/10.1080/15230430.2021.200189902224nas a2200229 4500008004100000245016400041210006900205260001200274300000800286490000700294520144700301100002401748700002301772700002201795700001501817700002101832700002201853700002201875700003201897700002101929856004401950 2021 eng d00aMetabolic capacity of the Antarctic cyanobacterium Phormidium pseudopriestleyi that sustains oxygenic photosynthesis in the presence of hydrogen sulfide0 aMetabolic capacity of the Antarctic cyanobacterium IPhormidium p c03/2021 a4260 v123 a

Sulfide inhibits oxygenic photosynthesis by blocking electron transfer between H2O and the oxygen-evolving complex in the D1 protein of Photosystem II. The ability of cyanobacteria to counter this effect has implications for understanding the productivity of benthic microbial mats in sulfidic environments throughout Earth history. In Lake Fryxell, Antarctica, the benthic, filamentous cyanobacterium Phormidium pseudopriestleyi creates a 1–2 mm thick layer of 50 µmol L−1 O2 in otherwise sulfidic water, demonstrating that it sustains oxygenic photosynthesis in the presence of sulfide. A metagenome-assembled genome of P. pseudopriestleyi indicates a genetic capacity for oxygenic photosynthesis, including multiple copies of psbA (encoding the D1 protein of Photosystem II), and anoxygenic photosynthesis with a copy of sqr (encoding the sulfide quinone reductase protein that oxidizes sulfide). The genomic content of P. pseudopriestleyi is consistent with sulfide tolerance mechanisms including increasing psbA expression or directly oxidizing sulfide with sulfide quinone reductase. However, the ability of the organism to reduce Photosystem I via sulfide quinone reductase while Photosystem II is sulfide-inhibited, thereby performing anoxygenic photosynthesis in the presence of sulfide, has yet to be demonstrated. 

1 aLumian, Jessica, E.1 aJungblut, Anne, D.1 aDillon, Megan, L.1 aHawes, Ian1 aDoran, Peter, T.1 aMackey, Tyler, J.1 aDick, Gregory, J.1 aGrettenberger, Christen, L.1 aSumner, Dawn, Y. uhttps://www.mdpi.com/2073-4425/12/3/42602152nas a2200253 4500008004100000245012600041210006900167260001200236300001600248490000700264520133900271100002201610700002101632700002501653700002001678700002201698700001701720700002201737700002201759700001901781700002201800700002301822856005301845 2021 eng d00aThermal legacy of a large paleolake in Taylor Valley, East Antarctica, as evidenced by an airborne electromagnetic survey0 aThermal legacy of a large paleolake in Taylor Valley East Antarc c08/2021 a3577 - 35930 v153 a

Previous studies of the lakes of the McMurdo Dry Valleys have attempted to constrain lake level history, and results suggest the lakes have undergone hundreds of meters of lake level change within the last 20 000 years. Past studies have utilized the interpretation of geologic deposits, lake chemistry, and ice sheet history to deduce lake level history; however a substantial amount of disagreement remains between the findings, indicating a need for further investigation using new techniques. This study utilizes a regional airborne resistivity survey to provide novel insight into the paleohydrology of the region. Mean resistivity maps revealed an extensive brine beneath the Lake Fryxell basin, which is interpreted as a legacy groundwater signal from higher lake levels in the past. Resistivity data suggest that active permafrost formation has been ongoing since the onset of lake drainage and that as recently as 1500–4000 years BP, lake levels were over 60 m higher than present. This coincides with a warmer-than-modern paleoclimate throughout the Holocene inferred by the nearby Taylor Dome ice core record. Our results indicate Mid to Late Holocene lake level high stands, which runs counter to previous research finding a colder and drier era with little hydrologic activity throughout the last 5000 years.

1 aMyers, Krista, F.1 aDoran, Peter, T.1 aTulaczyk, Slawek, M.1 aFoley, Neil, T.1 aBording, Thue, S.1 aAuken, Esben1 aDugan, Hilary, A.1 aMikucki, Jill, A.1 aFoged, Nikolaj1 aGrombacher, Denys1 aVirginia, Ross, A. uhttps://tc.copernicus.org/articles/15/3577/2021/02753nas a2200325 4500008004100000022001400041245011500055210007300170260001200243300001800255490000800273520178400281653001002065653001402075653001602089653000802105653001002113653001002123653001402133653001102147100002802158700002102186700003302207700002202240700002202262700002402284700002902308700002102337856006902358 2021 eng d a2169-895300aYear‐round and long‐term phytoplankton dynamics in Lake Bonney, a permanently ice‐covered Antarctic lake0 aYear‐round and long‐term phytoplankton dynamics in Lake Bonney a c04/2021 ae2020JG0059250 v1263 a

Lake Bonney (McMurdo Dry Valleys, east Antarctica) represents a year‐round refugium for life adapted to permanent extreme conditions. Despite intensive research since the 1960s, due to the logistical constraints posed by 4‐months of 24‐h darkness, knowledge of how the resident photosynthetic microorganisms respond to the polar winter is limited. In addition, the lake level has risen by more than 3 m since 2004: impacts of rapid lake level rise on phytoplankton community structure is also poorly understood. From 2004 to 2015 an in situ submersible spectrofluorometer (bbe FluoroProbe) was deployed in Lake Bonney during the austral summer to quantify the vertical structure of four functional algal groups (green algae, mixed algae, and cryptophytes, cyanobacteria). During the 2013–2014 field season the Fluoroprobe was mounted on autonomous cable‐crawling profilers deployed in both the east and west lobes of Lake Bonney, obtaining the first daily phytoplankton profiles through the polar night. Our findings showed that phytoplankton communities were differentially impacted by physical and chemical factors over long‐term versus seasonal time scales. Following a summer of rapid lake level rise (2010–2011), an increase in depth integrated chlorophyll a (chl‐a) occurred in Lake Bonney caused by stimulation of photoautotrophic green algae. Conversely, peaks in chl‐a during the polar night were associated with an increase in mixotrophic haptophytes and cryptophytes. Collectively our data reveal that phytoplankton groups possessing variable trophic abilities are differentially competitive during seasonal and long‐term time scales owing to periods of higher nutrients (photoautotrophs) versus light/energy limitation (mixotrophs).

10aalgae10aAntarctic10afluorometry10aice10alakes10alight10aprofiling10awinter1 aPatriarche, Jeffrey, D.1 aPriscu, John, C.1 aTakacs-Vesbach, Cristina, D.1 aWinslow, Luke, A.1 aMyers, Krista, F.1 aBuelow, Heather, N.1 aMorgan-Kiss, Rachael, M.1 aDoran, Peter, T. uhttps://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JG00592501864nas a2200193 4500008004100000245012800041210006900169260001200238520119500250653002401445653001801469653002501487100001801512700001801530700002101548700001401569700001801583856006901601 2020 eng d00aClimate from the McMurdo Dry Valleys, Antarctica, 1986 – 2017: Surface air temperature trends and redefined summer season0 aClimate from the McMurdo Dry Valleys Antarctica 1986 2017 Surfac c05/20203 a

The weather of the McMurdo Dry Valleys, Antarctica, the largest ice‐free region of the Antarctica, has been continuously monitored since 1985 with currently 14 operational meteorological stations distributed throughout the valleys. Because climate is based on a 30‐year record of weather, this is the first study to truly define the contemporary climate of the McMurdo Dry Valleys. Mean air temperature and solar radiation based on all stations were ‐20°C and 102 W m‐2, respectively. Depending on the site location, the mean annual air temperatures on the valleys floors ranged between ‐15°C and ‐30°C, and mean annual solar radiation varied between 72 W m‐2 and 122 W m‐2. Surface air temperature decreased by 0.7°C per decade from 1986 to 2006 at Lake Hoare station (longest continuous record), after which the record is highly variable with no trend. All stations with sufficiently long records showed similar trend shifts in 2005 ±1 year. Summer is defined as November through February, using a physically based process: up‐valley warming from the coast associated with a change in atmospheric stability.

10aMcMurdo Dry Valleys10asummer season10aweather observations1 aObryk, M., K.1 aDoran, P., T.1 aFountain, A., G.1 aMyers, M.1 aMcKay, C., P. uhttps://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JD03218002314nas a2200265 4500008004100000245012500041210006900166260001200235490000700247520147000254653001501724653001101739653001701750653001801767653001101785653004001796100002201836700001501858700002301873700002201896700002401918700002101942700002101963856006401984 2020 eng d00aEnergetic and environmental constraints on the community structure of benthic microbial mats in Lake Fryxell, Antarctica0 aEnergetic and environmental constraints on the community structu c02/20200 v963 a

Ecological communities are regulated by the flow of energy through environments. Energy flow is typically limited by access to photosynthetically active radiation (PAR) and oxygen concentration (O2). The microbial mats growing on the bottom of Lake Fryxell, Antarctica, have well-defined environmental gradients in PAR and (O2). We analyzed the metagenomes of layers from these microbial mats to test the extent to which access to oxygen and light controls community structure. We found variation in the diversity and relative abundances of Archaea, Bacteria and Eukaryotes across three (O2) and PAR conditions: high (O2) and maximum PAR, variable (O2) with lower maximum PAR, and low (O2) and maximum PAR. We found distinct communities structured by the optimization of energy use on a millimeter-scale across these conditions. In mat layers where (O2) was saturated, PAR structured the community. In contrast, (O2) positively correlated with diversity and affected the distribution of dominant populations across the three habitats, suggesting that meter-scale diversity is structured by energy availability. Microbial communities changed across covarying gradients of PAR and (O2). The comprehensive metagenomic analysis suggests that the benthic microbial communities in Lake Fryxell are structured by energy flow across both meter- and millimeter-scales.

10aAntarctica10aenergy10aLake Fryxell10amicrobial mat10aOxygen10aPhotosynthetically Active Radiation1 aDillon, Megan, L.1 aHawes, Ian1 aJungblut, Anne, D.1 aMackey, Tyler, J.1 aEisen, Jonathan, A.1 aDoran, Peter, T.1 aSumner, Dawn, Y. uhttps://academic.oup.com/femsec/article/96/2/fiz207/569719602205nas a2200205 4500008004100000245012400041210006900165260001200234300001300246490000700259520150700266100002201773700001501795700002301810700002201833700002401855700002101879700002101900856007801921 2020 eng d00aEnvironmental control on the distribution of metabolic strategies of benthic microbial mats in Lake Fryxell, Antarctica0 aEnvironmental control on the distribution of metabolic strategie c04/2020 ae02310530 v153 a

Ecological theories posit that heterogeneity in environmental conditions greatly affects community structure and function. However, the degree to which ecological theory developed using plant- and animal-dominated systems applies to microbiomes is unclear. Investigating the metabolic strategies found in microbiomes are particularly informative for testing the universality of ecological theories because microorganisms have far wider metabolic capacity than plants and animals. We used metagenomic analyses to explore the relationships between the energy and physicochemical gradients in Lake Fryxell and the metabolic capacity of its benthic microbiome. Statistical analysis of the relative abundance of metabolic marker genes and gene family diversity shows that oxygenic photosynthesis, carbon fixation, and flavin-based electron bifurcation differentiate mats growing in different environmental conditions. The pattern of gene family diversity points to the likely importance of temporal environmental heterogeneity in addition to resource gradients. Overall, we found that the environmental heterogeneity of photosynthetically active radiation (PAR) and oxygen concentration ([O2]) in Lake Fryxell provide the framework by which metabolic diversity and composition of the community is structured, in accordance with its phylogenetic structure. The organization of the resulting microbial ecosystems are consistent with the maximum power principle and the species sorting model.

1 aDillon, Megan, L.1 aHawes, Ian1 aJungblut, Anne, D.1 aMackey, Tyler, J.1 aEisen, Jonathan, A.1 aDoran, Peter, T.1 aSumner, Dawn, Y. uhttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.023105302540nas a2200289 4500008004100000245012600041210006900167260001200236490000800248520163000256653002101886653001501907653001701922653001501939653002401954653001901978100002101997700002102018700001902039700002402058700001902082700001702101700002402118700001902142700001702161856007202178 2020 eng d00aGeochemistry of aeolian material from the McMurdo Dry Valleys, Antarctica: Insights into Southern Hemisphere dust sources0 aGeochemistry of aeolian material from the McMurdo Dry Valleys An c10/20200 v5473 a

In the Southern Hemisphere, the major sources of dust and other aeolian materials are from Patagonia, South Africa, Australia, and New Zealand. Dust from Patagonia and New Zealand has been identified in ice cores throughout Antarctica, suggesting that during arid and windy periods, such as glacial periods, dust can be entrained and transported onto the continent. However, little information exists on modern Antarctic dust sources, transport, and its role in the Southern Hemisphere dust cycle. We present the first geochemical characterization of aeolian materials collected at five heights (between 5 cm and 100 cm) above the surface in four valleys within the McMurdo Dry Valleys, the largest ice-free area in Antarctica. Our mineralogy data indicate that these materials are primarily derived from local rocks of the McMurdo Volcanics, Ferrar Dolerite, Beacon Sandstone and Granite Harbor Intrusives, with varying contributions of each rock type dependent on the valley location. While major oxide, trace element and rare earth element data show that low elevation and coastal locations (with respect to the Ross Sea) are dominated by local sources, high elevation and inland locations have accumulated both local materials and dust from other distant Southern Hemisphere sources. This far-traveled material may not be accumulating today, but represents a paleo source that is resuspended from the soils. By geochemically “fingerprinting” aeolian materials from the MDV, we can better inform future studies on the transport of materials within Antarctica and between Southern Hemisphere land masses.

10aaeolian material10aAntarctica10amajor oxides10amineralogy10arare earth elements10atrace elements1 aDiaz, Melisa, A.1 aWelch, Susan, A.1 aSheets, J., M.1 aWelch, Kathleen, A.1 aKhan, Alia, L.1 aAdams, Byron1 aMcKnight, Diane, M.1 aCary, Craig, S1 aLyons, Berry uhttps://www.sciencedirect.com/science/article/pii/S0012821X2030404002119nas a2200217 4500008004100000245007600041210006900117260001200186520131800198653001101516653003001527653002801557653002201585653002401607653001201631653001801643100002401661700002101685700002001706856017501726 2020 eng d00aGIS tool to predict photosynthetically active radiation in a Dry Valley0 aGIS tool to predict photosynthetically active radiation in a Dry c04/20203 a

Understanding primary productivity is a core research area of the National Science Foundation's Long-Term Ecological Research Network. This study presents the development of the GIS-based Topographic Solar Photosynthetically Active Radiation (T-sPAR) toolbox for Taylor Valley. It maps surface photosynthetically active radiation using four meteorological stations with ~20 years of data. T-sPAR estimates were validated with ground-truth data collected at Taylor Valley's major lakes during the 2014–15 and 2015–16 field seasons. The average daily error ranges from 0.13 mol photons m-2 day-1 (0.6%) at Lake Fryxell to 3.8 mol photons m-2 day-1 (5.8%) at Lake Hoare. We attribute error to variability in terrain and sun position. Finally, a user interface was developed in order to estimate total daily surface photosynthetically active radiation for any location and date within the basin. T-sPAR improves upon existing toolboxes and models by allowing for the inclusion of a statistical treatment of light attenuation due to cloud cover. The T-sPAR toolbox could be used to inform biological sampling sites based on radiation distribution, which could collectively improve estimates of net primary productivity, in some cases by up to 25%.

10aArcMap10aautomated weather station10adigital elevation model10aice-covered lakes10aMcMurdo Dry Valleys10aR model10aTaylor Valley1 aAcosta, Dimitri, R.1 aDoran, Peter, T.1 aMyers, Madeline uhttps://www.cambridge.org/core/journals/antarctic-science/article/gis-tool-to-predict-photosynthetically-active-radiation-in-a-dry-valley/BD0BE4FF6A8F3DAAF32D69879728707803683nas a2200997 4500008004100000245008200041210006900123260001200192490000600204520084100210100002601051700001901077700002001096700001401116700002501130700002501155700001701180700001701197700001901214700002601233700002301259700002701282700002301309700002101332700003101353700001801384700002101402700002001423700003001443700001501473700002001488700001901508700002501527700002301552700001901575700002101594700001701615700002201632700002101654700002601675700002301701700001101724700001701735700002201752700002101774700003101795700002401826700002201850700001501872700002201887700001801909700001701927700002501944700002201969700001901991700002702010700001602037700001802053700002202071700003202093700002302125700002302148700002002171700002202191700002002213700002702233700001802260700002102278700001902299700002302318700001502341700002302356700002202379700002402401700002102425700002302446700002102469700001802490700001802508700001902526700001402545700002802559700001702587700002702604856005402631 2020 eng d00aA global database of soil nematode abundance and functional group composition0 aglobal database of soil nematode abundance and functional group  c03/20200 v73 a

As the most abundant animals on earth, nematodes are a dominant component of the soil community. they play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil samples from all continents and biomes. For geospatial mapping purposes these samples are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into the spatial distribution patterns of soil nematode abundance and community composition, and the environmental drivers shaping these patterns.

1 avan den Hoogen, Johan1 aGeisen, Stefan1 aWall, Diana, H.1 aWardle, D1 aTraunspurger, Walter1 ade Goede, Ron, G. M.1 aAdams, Byron1 aAhmad, Wasim1 aFerris, Howard1 aBardgett, Richard, D.1 aBonkowski, Michael1 aCampos-Herrera, Raquel1 aCares, Juvenil, E.1 aCaruso, Tancredi1 aCaixeta, Larissa, de Brito1 aChen, Xiaoyun1 aCosta, Sofia, R.1 aCreamer, Rachel1 aCastro, José, da Cunha e1 aDam, Marie1 aDjigal, Djibril1 aEscuer, Miguel1 aGriffiths, Bryan, S.1 aGutiérrez, Carmen1 aHohberg, Karin1 aKalinkina, Daria1 aKardol, Paul1 aKergunteuil, Alan1 aKorthals, Gerard1 aKrashevska, Valentyna1 aKudrin, Alexey, A.1 aLi, Qi1 aLiang, Wenju1 aMagilton, Matthew1 aMarais, Mariette1 aMartín, José, Antonio Ro1 aMatveeva, Elizaveta1 aMayad, El, Hassan1 aMzough, E.1 aMulder, Christian1 aMullin, Peter1 aNeilson, Roy1 aNguyen, T., A. Duong1 aNielsen, Uffe, N.1 aOkada, Hiroaki1 aRius, Juan, Emilio Pal1 aPan, Kaiwen1 aPeneva, Vlada1 aPellissier, Loïc1 ada Silva, Julio, Carlos Per1 aPitteloud, Camille1 aPowers, Thomas, O.1 aPowers, Kirsten1 aQuist, Casper, W.1 aRasmann, Sergio1 aMoreno, Sara, Sánchez1 aScheu, Stefan1 aSetälä, Heikki1 aSushchuk, Anna1 aTiunov, Alexei, V.1 aTrap, Jean1 aVestergård, Mette1 aVillenave, Cecile1 aWaeyenberge, Lieven1 aWilschut, Rutger1 aWright, Daniel, G.1 aKeith, Aidan, M.1 aYang, Jiue-in1 aSchmidt, Olaf1 aBouharroud, R.1 aFerji, Z.1 avan der Putten, Wim, H.1 aRouth, Devin1 aCrowther, Thomas, Ward uhttps://www.nature.com/articles/s41597-020-0437-302448nas a2200217 4500008004100000245010000041210006900141260001200210490000700222520174400229100001201973700001901985700002702004700002102031700001602052700001702068700002902085700002302114700002102137856007202158 2020 eng d00aMethane production in the oxygenated water column of a perennially ice‐covered Antarctic lake0 aMethane production in the oxygenated water column of a perennial c01/20200 v653 a

Aerobic methane production in aquatic ecosystems impacts the global atmospheric budget of methane, but the extent, mechanism, and taxa responsible for producing this greenhouse gas are not fully understood. Lake Bonney (LB), a perennially ice‐covered Antarctic lake, has cold hypersaline waters underlying an oxygenated freshwater layer. We present temporal methane concentration profiles in LB indicating methane production in the oxygenated (> 200% air saturation) water. Experiments amended with methylphosphonate (MPn) yielded methane generation, suggesting in situ methanogenesis via the carbon‐phosphorus (C‐P) lyase pathway. Enrichment cultures from the lake were used to isolate five bacterial strains capable of generating methane when supplied with MPn as the sole P source. Based on 16S rRNA gene sequencing, the isolates belong to the Proteobacteria (closely related to Marinomonas, Hoeflea, and Marinobacter genera) and Bacteroidetes (Algoriphagus genus). 16S rRNA metagenomic sequencing confirms the presence of these taxa in LB. None of the isolated species were reported to be capable to produce methane. In addition, orthologs of the phosphoenolpyruvate mutase gene (PepM) and methylphosphonate synthase (MPnS), enzymes involved in phosphonate and MPn biosynthesis, were widely spread in the LB shotgun metagenomic libraries; genes related to C‐P lyase pathways (phn gene clusters) were also abundant. 16S rRNA and mcrA genes of anaerobic methanogens were absent in both 16S rRNA and metagenomics libraries. These data reveal that in situ aerobic biological methane production is likely a significant source of methane in LB.

1 aLi, Wei1 aDore, John, E.1 aSteigmeyer, August, J.1 aCho, Yong‐Joon1 aKim, Ok-Sun1 aLiu, Yongqin1 aMorgan-Kiss, Rachael, M.1 aSkidmore, Mark, L.1 aPriscu, John, C. uhttps://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lno.1125703158nas a2200181 4500008004100000245011200041210006900153260001200222300001200234490000700246520256300253100002402816700002502840700002002865700002102885700002202906856004802928 2020 eng d00aThe seasonal evolution of albedo across glaciers and the surrounding landscape of Taylor Valley, Antarctica0 aseasonal evolution of albedo across glaciers and the surrounding c03/2020 a769-7880 v143 a

The McMurdo Dry Valleys (MDVs) of Antarctica are a polar desert ecosystem consisting of alpine glaciers, ice-covered lakes, streams, and expanses of vegetation-free rocky soil. Because average summer temperatures are close to 0 ∘C, the MDV ecosystem in general, and glacier melt dynamics in particular, are both closely linked to the energy balance. A slight increase in incoming radiation or change in albedo can have large effects on the timing and volume of meltwater. However, the seasonal evolution or spatial variability of albedo in the valleys has yet to fully characterized. In this study, we aim to understand the drivers of landscape albedo change within and across seasons. To do so, a box with a camera, GPS, and shortwave radiometer was hung from a helicopter that flew transects four to five times a season along Taylor Valley. Measurements were repeated over three seasons. These data were coupled with incoming radiation measured at six meteorological stations distributed along the valley to calculate the distribution of albedo across individual glaciers, lakes, and soil surfaces. We hypothesized that albedo would decrease throughout the austral summer with ablation of snow patches and increasing sediment exposure on the glacier and lake surfaces. However, small snow events (<6 mm water equivalent) coupled with ice whitening caused spatial and temporal variability of albedo across the entire landscape. Glaciers frequently followed a pattern of increasing albedo with increasing elevation, as well as increasing albedo moving from east to west laterally across the ablation zone. We suggest that spatial patterns of albedo are a function of landscape morphology trapping snow and sediment, longitudinal gradients in snowfall magnitude, and wind-driven snow redistribution from east to west along the valley. We also compare our albedo measurements to the MODIS albedo product and found that overall the data have reasonable agreement. The mismatch in spatial scale between these two datasets results in variability, which is reduced after a snow event due to albedo following valley-scale gradients of snowfall magnitude. These findings highlight the importance of understanding the spatial and temporal variability in albedo and the close coupling of climate and landscape response. This new understanding of landscape albedo can constrain landscape energy budgets, better predict meltwater generation on from MDV glaciers, and how these ecosystems will respond to changing climate at the landscape scale.

1 aBergstrom, Anna, J.1 aGooseff, Michael, N.1 aMyers, Madeline1 aDoran, Peter, T.1 aCross, Julian, M. uhttps://www.the-cryosphere.net/14/769/2020/01789nas a2200205 4500008004100000245008500041210006900126260001200195520112400207653001601331653001801347653001001365653001501375653001601390100001901406700002101425700002201446700002101468856009401489 2020 eng d00aSubglacial brine flow and wind-induced internal waves in Lake Bonney, Antarctica0 aSubglacial brine flow and windinduced internal waves in Lake Bon c02/20203 a

Brine beneath Taylor Glacier has been proposed to enter the proglacial west lobe of Lake Bonney (WLB) as well as from Blood Falls, a surface discharge point at the Taylor Glacier terminus. The brine strongly influences the geochemistry of the water column of WLB. Year-round measurements from this study are the first to definitively identify brine intrusions from a subglacial entry point into WLB. Furthermore, we excluded input from Blood Falls by focusing on winter dynamics when the absence of an open water moat prevents surface brine entry. Due to the extremely high salinities below the chemocline in WLB, density stratification is dominated by salinity, and temperature can be used as a passive tracer. Cold brine intrusions enter WLB at the glacier face and intrude into the water column at the depth of neutral buoyancy, where they can be identified by anomalously cold temperatures at that depth. High-resolution measurements also reveal under-ice internal waves associated with katabatic wind events, a novel finding that challenges long-held assumptions about the stability of the WLB water column.

10aDry valleys10ahypersalinity10alakes10aproglacial10atemperature1 aLawrence, Jade1 aDoran, Peter, T.1 aWinslow, Luke, A.1 aPriscu, John, C. uhttps://www.cambridge.org/core/services/aop-cambridge-core/content/view/S095410202000003602367nas a2200205 4500008004100000245011400041210006900155260001200224300001400236490000800250520166200258100002501920700002701945700002801972700002602000700002002026700002002046700002102066856007402087 2019 eng d00aDifferential incorporation of bacteria, organic matter, and inorganic ions into lake ice during ice formation0 aDifferential incorporation of bacteria organic matter and inorga c02/2019 a585 - 6000 v1243 a

The segregation of bacteria, inorganic solutes, and total organic carbon between liquid water and ice during winter ice formation on lakes can significantly influence the concentration and survival of microorganisms in icy systems, and their roles in biogeochemical processes. Our study quantifies the distributions of bacteria and solutes between liquid and solid water phases during progressive freezing. We simulated lake ice formation in mesocosm experiments using water from perennially (Antarctica) and seasonally (Alaska and Montana, USA) ice covered lakes. We then computed concentration factors and effective segregation coefficients, which are parameters describing the incorporation of bacteria and solutes into ice. Experimental results revealed that, contrary to major ions, bacteria were readily incorporated into ice and did not concentrate in the liquid phase. The organic matter incorporated into the ice was labile, amino acid-like material, differing from the humic-like compounds that remained in the liquid phase. Results from a control mesocosm experiment (dead bacterial cells) indicated that viability of bacterial cells did not influence the incorporation of free bacterial cells into ice, but did have a role in the formation and incorporation of bacterial aggregates. Together, these findings demonstrate that bacteria, unlike other solutes, were preferentially incorporated into lake-ice during our freezing experiments, a process controlled mainly by the initial solute concentration of the liquid water source, regardless of cell viability.

1 aSantibáñez, Pamela1 aMichaud, Alexander, B.1 aVick-Majors, Trista, J.1 aD’Andrilli, Juliana1 aChiuchiolo, Amy1 aHand, Kevin, P.1 aPriscu, John, C. uhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JG00482502573nas a2200265 4500008004100000022001400041245010400055210006900159260001200228300001400240490000700254520177600261653002002037653002102057653001502078653001702093653002402110653001202134653002502146100001202171700002002183700001602203700002902219856005902248 2019 eng d a0948-305500aDrivers of protistan community autotrophy and heterotrophy in chemically stratified Antarctic lakes0 aDrivers of protistan community autotrophy and heterotrophy in ch c01/2019 a225 - 2390 v823 a

Single-celled, eukaryotic microorganisms, known as protists, are responsible for 2 important, yet opposing, metabolic activities within aquatic food webs. They are major primary producers and highly active predators in marine and fresh water systems. While genomics has accelerated in recent years for this taxonomically diverse group, our understanding of the metabolic capabilities of most protists remains limited. It is also poorly understood how protist trophic mode is affected by biotic and abiotic factors, and therefore it is difficult to predict how events such as global climate change will affect the balance between autotrophic and heterotrophic activities in protist communities. To address open questions regarding how protist metabolic versatility is influenced by their environment, we characterized the potential for carbon fixation versus organic carbon degradation using enzymatic assays (RubisCO and β-D-glucosaminidase, respectively) within the water columns of ice-covered lakes in McMurdo Dry Valleys (MDV), Antarctica. Steep physical and chemical gradients in the water columns, microorganism domination and minimal allochthonous inputs makes the MDV lakes uniquely suited to investigate environment-microbe interactions. Spatial trends in RubisCO and β-D-glucosaminidase activities were lake-specific and vertically stratified within the water columns. Moreover, bottom-up drivers controlling the activity of C-fixation vs. organic C-degradation among the MDV protist communities were distinct between the upper photic vs. the deep, aphotic zones. We conclude that differential controls over major C-cycling enzymes have important implications on the influence of environmental change on the carbon and nutrient cycles in the MDV lakes.

10aAntarctic lakes10aAquatic protists10aAutotrophy10aHeterotrophy10aMcMurdo Dry Valleys10aRubisCO10aβ-D-glucosaminidase1 aLi, Wei1 aDolhi-Binder, J1 aCariani, ZE1 aMorgan-Kiss, Rachael, M. uhttps://www.int-res.com/abstracts/ame/v82/n3/p225-239/02504nas a2200229 4500008004100000245007200041210006700113260001200180490000800192520178600200100001701986700002202003700002202025700002402047700001502071700002902086700002502115700002102140700002002161700002002181856007302201 2019 eng d00aThe Geochemistry of Englacial Brine From Taylor Glacier, Antarctica0 aGeochemistry of Englacial Brine From Taylor Glacier Antarctica c03/20190 v1243 a

Blood Falls is a hypersaline, iron‐rich discharge at the terminus of the Taylor Glacier in the McMurdo Dry Valleys, Antarctica. In November 2014, brine in a conduit within the glacier was penetrated and sampled using clean‐entry techniques and a thermoelectric melting probe called the IceMole. We analyzed the englacial brine sample for filterable iron (fFe), total Fe, major cations and anions, nutrients, organic carbon, and perchlorate. In addition, aliquots were analyzed for minor and trace elements and isotopes including δD and δ18O of water, δ34S and δ18O of sulfate, 234U, 238U, δ11B, 87Sr/86Sr, and δ81Br. These measurements were made in order to (1) determine the source and geochemical evolution of the brine and (2) compare the chemistry of the brine to that of nearby hypersaline lake waters and previous supraglacially sampled collections of Blood Falls outflow that were interpreted as end‐member brines. The englacial brine had higher Cl− concentrations than the Blood Falls end‐member outflow; however, other constituents were similar. The isotope data indicate that the water in the brine is derived from glacier melt. The H4SiO4 concentrations and U and Sr isotope suggest a high degree of chemical weathering products. The brine has a low N:P ratio of ~7.2 with most of the dissolved inorganic nitrogen in the form of NH4+. Dissolved organic carbon concentrations are similar to end‐member outflow values. Our results provide strong evidence that the original source of solutes in the brine was ancient seawater, which has been modified with the addition of chemical weathering products.

1 aLyons, Berry1 aMikucki, Jill, A.1 aGerman, Laura, A.1 aWelch, Kathleen, A.1 aWelch, Sue1 aGardner, Christopher, B.1 aTulaczyk, Slawek, M.1 aPettit, Erin, C.1 aKowalski, Julia1 aDachwald, Bernd uhttps://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JG00441102216nas a2200193 4500008004100000245012200041210006900163260001200232520155300244653001501797653001701812653002101829653002901850653001801879100002101897700001501918700001701933856007201950 2019 eng d00aThe geochemistry of glacial deposits in Taylor Valley, Antarctica: Comparison to upper continental crustal abundances0 ageochemistry of glacial deposits in Taylor Valley Antarctica Com c05/20193 a

Wet-based glacial deposits have been used traditionally as an analog for upper continental crust (UCC) abundances. To provide more information on the validity of using glacial deposits from wet-based glaciers, samples deposited by the dry-based polar glaciers located in Taylor Valley, Antarctica, were collected. Stream channel sediments, comprised of igneous, metamorphic, and sedimentary rocks initially deposited as glacial tills by polar glaciers, were analyzed by XRF, ICP-MS, and SEM. Based on the Chemical Index of Alteration values and A–CN–K ternary diagram, there are low levels of chemical weathering in these tills. Additionally, major and trace element geochemical data are compared to the average UCC values. The observed discrepancies between the mean UCC and Antarctic samples develop from the existence of mafic components, most likely the McMurdo Volcanic Group and Ferrar Dolerite, being present in the Taylor Valley tills. Even though the mafic material typically comprises 3–7% of the till, the volcanic rocks have a significant influence on the tills’ bulk geochemistry. The existence of this mafic fraction in the dry-based glacial tills results from the reduced rate of weathering, as compared to wet-based glaciers. Geochemical analyses of the dry-based glacial tills in polar deserts, such as those found in Taylor Valley, may provide a better representative composition of the original material than wet-based glaciers and need to be incorporated into upper continental crust calculations.

10aAntarctica10ageochemistry10aglacial deposits10apolar dry-based glaciers10aTaylor Valley1 aDowling, Carolyn1 aWelch, Sue1 aLyons, Berry uhttps://www.sciencedirect.com/science/article/pii/S088329271930124602300nas a2200289 4500008004100000245009400041210006900135260001200204490000800216520140200224653002001626653001501646653002001661653002401681653001401705653001901719100001901738700002501757700002401782700002601806700002201832700001901854700002501873700002401898700002401922856006401946 2019 eng d00aSabbea gen. nov., a new diatom genus (Bacillariophyta) from continental Antarctica0 aiSabbea gen novi a new diatom genus Bacillariophyta from contine c09/20190 v4183 a

The non-marine diatom flora of the Antarctic Continent includes several endemic taxa recorded over the past 100 years. One of these taxa, Navicula adminensis D.Roberts & McMinn, was described from the Vestfold Hills, East Antarctica. Detailed light and scanning electron microscopy observations have shown that based on its morphological features, the species does not belong to the genus Navicula sensu stricto. To determine the most closely related genera to N. adminensis, the morpho- logical features of Adlafia, Kobayasiella, Envekadea, Stenoneis, Berkeleya, Climaconeis, and Parlibellus were compared with those of N. adminensis. Although each of these genera shows one or more similar features, none of them accommodates the salient morphological characteristics of N. adminensis. Therefore, a new genus, Sabbea gen. nov., is herein described, and Navicula adminensis is formally transferred to the new genus as Sabbea adminensis comb. nov. The genus Sabbea is characterized by uniseriate striae composed of small, rounded areolae occluded externally by individual hymenes, a rather simple raphe structure with straight, short proximal ends and short terminal raphe fissures, open girdle bands with double perforation and a very shallow mantle.

10aBacillariophyta10aCape Royds10aEast Antarctica10aMcMurdo Dry Valleys10anew genus10aVestfold Hills1 aBishop, Jordan1 aKopalová, Kateřina1 aDarling, Joshua, P.1 aSchulte, Nicholas, O.1 aKohler, Tyler, J.1 aMcMinn, Andrew1 aSpaulding, Sarah, A.1 aMcKnight, Diane, M.1 aVan de Vijver, Bart uhttps://www.mapress.com/j/pt/article/view/phytotaxa.418.1.202454nas a2200289 4500008004100000022001400041245011100055210006900166260001200235300001600247490000700263520153600270653001501806653001501821653003701836653002101873653002401894653003201918100002001950700001601970700002601986700002102012700001402033700002302047700001502070856007902085 2019 eng d a1558-842400aMeteorological connectivity from regions of high biodiversity within the McMurdo Dry Valleys of Antarctica0 aMeteorological connectivity from regions of high biodiversity wi c11/2019 a2437 - 24520 v583 a

Meteorological connectivity between biological hot spots of the McMurdo Dry Valleys (MDVs) of Antarctica is thought to play a role in species distribution and abundance through the aeolian transport of bioaerosols. Understanding the potential role of such meteorological connectivity requires an understanding of near-surface wind flow within and between valley airsheds. To address this, we applied Lagrangian wind trajectory modeling to mesoscale (spatial resolution of ~1 km) weather model output to predict connectivity pathways, focusing on regions of high biodiversity. Our models produce maps of a likelihood metric of wind connectivity that demonstrate the synoptic and mesoscale dependence of connections between local, near-local, and nonlocal areas on wind transport, modulated by synoptic weather and topographic forcing. These connectivity areas can have spatial trends modulated by the synoptic weather patterns and locally induced topographically forced winds. This method is transferrable to other regions of Antarctica for broader terrestrial, coastal, and offshore ecological connectivity research. Also, our analysis and methods can inform better placement of aeolian dust and bioaerosol samplers in the McMurdo Dry Valleys, provide preliminary guidelines behind the meteorological controls of sediment transport and smaller particle distribution, and present quantifiable knowledge informing new hypotheses around the potential of wind acting as a physical driver for biological connectivity in the MDVs.

10aAntarctica10aatmosphere10abiosphere-atmosphere interaction10amesoscale models10amesoscale processes10anumerical analysis/modeling1 aKaturji, Marwan1 aKhan, Basit1 aSprenger, Michael, A.1 aDatta, Rajasweta1 aJoy, Kurt1 aZawar-Reza, Peyman1 aHawes, Ian uhttps://journals.ametsoc.org/view/journals/apme/58/11/jamc-d-18-0336.1.xml01525nas a2200145 4500008004100000245008300041210006900124260001200193490000800205520102800213100002201241700002101263700002101284856007401305 2019 eng d00aPrediction of ice-free conditions for a perennially ice-covered Antarctic lake0 aPrediction of icefree conditions for a perennially icecovered An c02/20190 v1243 a

Although perennially ice-covered Antarctic lakes have experienced variable ice thicknesses over the past several decades, future ice thickness trends and associated aquatic biological responses under projected global warming remain unknown. Heat stored in the water column in chemically stratified Antarctic lakes that have mid-depth temperature maxima, can significantly influence the ice thickness trends via upward heat flux to the ice/water interface. We modeled ice thickness of the west of lobe of Lake Bonney, Antarctica based on possible future climate scenarios utilizing a 1D thermodynamic model that accounts for surface radiative fluxes as well as the heat flux associated with the temperature evolution of the water column. Model results predict that the ice cover of Lake Bonney will shift from perennial to seasonal within one to four decades, a change that will drastically influence ecosystem processes within the lake.

1 aObryk, Maciek, K.1 aDoran, Peter, T.1 aPriscu, John, C. uhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JF00475603892nas a2200949 4500008004100000245007900041210006900120260001200189490000800201520116600209100002601375700001901401700001701420700001901437700002501456700001401481700002501495700001701520700001701537700002601554700002601580700002301606700002701629700002301656700002101679700003101700700001801731700002101749700002001770700003001790700001501820700002001835700001901855700002501874700002301899700001901922700002101941700001701962700002201979700002102001700002602022700002302048700001102071700001702082700002202099700002102121700003102142700002402173700002202197700002202219700001802241700001702259700002502276700002202301700001902323700002702342700001602369700001802385700002202403700003202425700002302457700002302480700002002503700002202523700002002545700002702565700001802592700002102610700001902631700002302650700001502673700002202688700002302710700002202733700002402755700002002779700002102799700002302820700001802843700002702861856005402888 2019 eng d00aSoil nematode abundance and functional group composition at a global scale0 aSoil nematode abundance and functional group composition at a gl c08/20190 v5723 a

Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, few quantitative, spatially explicit models of the active belowground community currently exist. In particular, nematodes are the most abundant animals on Earth, filling all trophic levels in the soil food web. Here we use 6,759 georeferenced samples to generate a mechanistic understanding of the patterns of the global abundance of nematodes in the soil and the composition of their functional groups. The resulting maps show that 4.4 ± 0.64 × 1020 nematodes (with a total biomass of approximately 0.3 gigatonnes) inhabit surface soils across the world, with higher abundances in sub-Arctic regions (38% of total) than in temperate (24%) or tropical (21%) regions. Regional variations in these global trends also provide insights into local patterns of soil fertility and functioning. These high-resolution models provide the first steps towards representing soil ecological processes in global biogeochemical models and will enable the prediction of elemental cycling under current and future climate scenarios.

1 avan den Hoogen, Johan1 aGeisen, Stefan1 aRouth, Devin1 aFerris, Howard1 aTraunspurger, Walter1 aWardle, D1 ade Goede, Ron, G. M.1 aAdams, Byron1 aAhmad, Wasim1 aAndriuzzi, Walter, S.1 aBardgett, Richard, D.1 aBonkowski, Michael1 aCampos-Herrera, Raquel1 aCares, Juvenil, E.1 aCaruso, Tancredi1 aCaixeta, Larissa, de Brito1 aChen, Xiaoyun1 aCosta, Sofia, R.1 aCreamer, Rachel1 aCastro, José, Mauro da C1 aDam, Marie1 aDjigal, Djibril1 aEscuer, Miguel1 aGriffiths, Bryan, S.1 aGutiérrez, Carmen1 aHohberg, Karin1 aKalinkina, Daria1 aKardol, Paul1 aKergunteuil, Alan1 aKorthals, Gerard1 aKrashevska, Valentyna1 aKudrin, Alexey, A.1 aLi, Qi1 aLiang, Wenju1 aMagilton, Matthew1 aMarais, Mariette1 aMartín, José, Antonio Ro1 aMatveeva, Elizaveta1 aMayad, El, Hassan1 aMulder, Christian1 aMullin, Peter1 aNeilson, Roy1 aNguyen, T., A. Duong1 aNielsen, Uffe, N.1 aOkada, Hiroaki1 aRius, Juan, Emilio Pal1 aPan, Kaiwen1 aPeneva, Vlada1 aPellissier, Loïc1 ada Silva, Julio, Carlos Per1 aPitteloud, Camille1 aPowers, Thomas, O.1 aPowers, Kirsten1 aQuist, Casper, W.1 aRasmann, Sergio1 aMoreno, Sara, Sánchez1 aScheu, Stefan1 aSetälä, Heikki1 aSushchuk, Anna1 aTiunov, Alexei, V.1 aTrap, Jean1 avan der Putten, W1 aVestergård, Mette1 aVillenave, Cecile1 aWaeyenberge, Lieven1 aWall, Diana, H.1 aWilschut, Rutger1 aWright, Daniel, G.1 aYang, Jiue-in1 aCrowther, Thomas, Ward uhttps://www.nature.com/articles/s41586-019-1418-602017nas a2200133 4500008004100000245011800041210006900159260005700228490000900285520149000294100002001784700002101804856005801825 2019 eng d00aSpatiotemporal impact of snow on underwater photosynthetically active radiation in Taylor Valley, East Antarctica0 aSpatiotemporal impact of snow on underwater photosynthetically a aBaton Rouge, LAbLouisiana State Universityc08/20190 vM.S.3 a

The role of snow on underwater photosynthetically active radiation (UW PAR) in the McMurdo Dry Valleys (MDVs) has been understudied due to lack of a detailed snowfall record. Research has shown that a relationship between snow cover and UW PAR exists, but the extent has never been evaluated in great detail. Although annual snowfall values in the MDVs are low (3 to 50 mm water equivalent annually), trends of increasing snowfall on the continent under future warming conditions could lead to an increased role for snow in regulating UW PAR (and associated primary productivity). Here, I discuss evidence from the snowfall record, surface PAR, and UW PAR, of the influence of snowfall on UW PAR in the major lakes of Taylor Valley. This study aims to quantify the spatiotemporal impact of lake ice snow packs on UW PAR in Taylor Valley from field surveys, long-term UW PAR, and meteorological data. Lake Fryxell has the strongest seasonality to precipitation, which decreases inland. On average, Lake Fryxell also has the most days with snow cover on the lake ice. Lake Hoare is experiencing an increase in Fall snow persistence since the 2007 snow year. Snow less than 0.5 mm snow water equivalent (SWE) can suppress UW PAR by 40%. The calendar day that snow falls often determines whether phototrophs will switch from photosynthesis to respiration, which suggests the importance to seasonality in determining the impact of snow on photoautotrophs and lake-wide carbon budget.

1 aMyers, Madeline1 aDoran, Peter, T. uhttps://digitalcommons.lsu.edu/gradschool_theses/496502534nas a2200229 4500008004100000245010900041210006900150260001200219300001600231490000800247520179600255100002102051700001702072700002402089700001502113700002302128700001902151700002402170700001902194700001702213856007402230 2018 eng d00aAeolian material transport and its role in landscape connectivity in the McMurdo Dry Valleys, Antarctica0 aAeolian material transport and its role in landscape connectivit c12/2018 a3323 - 33370 v1233 a

Arid regions, particularly polar and alpine desert environments, have diminished landscape connectivity compared to temperate regions due to limited and/or seasonal hydrological processes. For these environments, aeolian processes play a particularly important role in landscape evolution and biotic community vitality through nutrient and solute additions. The McMurdo Dry Valleys (MDV) are the largest ice-free area in Antarctica and are potentially a major source of aeolian material for the continent. From this region, samples were collected at five heights (~5, 10, 20, 50, and 100 cm) above the surface seasonally for 2013 through 2015 from Alatna Valley, Victoria Valley, Miers Valley, and Taylor Valley (Taylor Glacier, East Lake Bonney, F6 (Lake Fryxell), and Explorer’s Cove). Despite significant geological separation and varying glacial histories, low-elevation and coastal sites had similar major ion chemistries, as did high-elevation and inland locations. This locational clustering of compositions was also evident in scanning electron microscopy images and principal component analyses, particularly for samples collected at ~100 cm above the surface. Compared to published soil literature, aeolian material in Taylor Valley demonstrates a primarily down-valley transport of material toward the coast. Soluble N:P ratios in the aeolian material reflect relative nutrient enrichments seen in MDV soils and lakes, where younger, coastal soils are relatively N depleted, while older, up-valley soils are relatively P depleted. The aeolian transport of materials, including water-soluble nutrients, is an important vector of connectivity within the MDV and provides a mechanism to help “homogenize” the geochemistry of both soil and aquatic ecosystems.

1 aDiaz, Melisa, A.1 aAdams, Byron1 aWelch, Kathleen, A.1 aWelch, Sue1 aOpiyo, Stephen, O.1 aKhan, Alia, L.1 aMcKnight, Diane, M.1 aCary, Craig, S1 aLyons, Berry uhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2017JF00458910050nas a2202965 4500008004100000245007300041210006900114260001200183300001200195490000700207520154900214653001701763653001101780653001201791653002101803653001301824653001301837100002001850700002201870700001601892700002201908700002301930700001701953700002801970700002001998700002502018700001802043700002402061700001602085700002202101700002002123700002702143700002002170700002202190700002302212700003102235700002002266700002302286700002702309700002202336700002702358700002702385700001602412700001902428700002302447700002102470700002202491700001802513700002302531700002802554700002502582700002302607700002002630700002902650700002502679700002002704700002602724700002602750700001702776700002402793700002502817700002302842700002202865700001902887700002002906700002102926700002202947700002102969700001802990700001703008700002203025700001703047700002503064700001903089700002603108700002203134700001903156700002103175700001903196700002703215700003003242700002403272700002403296700001703320700002303337700003203360700002103392700002403413700002203437700002903459700001403488700003103502700002303533700001903556700002303575700002603598700001803624700002103642700001603663700001803679700002403697700002103721700002003742700001903762700001703781700001903798700002103817700002003838700002603858700002003884700002003904700002003924700002503944700002003969700002703989700002404016700003304040700001804073700001504091700002304106700002204129700002004151700001704171700002404188700001804212700002404230700002104254700002204275700002104297700002004318700002004338700002804358700002604386700001704412700002104429700001904450700002304469700003104492700002604523700002004549700002704569700002204596700002104618700002204639700002004661700002804681700001804709700002204727700002604749700002004775700001904795700002404814700001804838700002404856700002604880700001804906700002304924700002504947700002804972700002205000700002505022700001505047700001705062700001505079700003105094700001905125700001805144700002605162700002405188700001905212700001805231700002205249700002605271700002405297700002005321700002405341700002105365700002905386700002105415700002205436700002005458700001905478700002405497700002505521700002105546700002805567700001905595700002205614700001505636700002605651700002105677700002105698700002505719700002205744700001905766700002805785700002305813700002605836700002105862700002105883700002705904700002805931700002105959700001905980700001905999700003006018700002106048700002406069700003206093700003606125700001806161700001606179700002206195700002306217700001906240700001806259700001506277700002106292700002606313700003306339700001706372700002006389700002106409700002406430700002106454700002206475700001906497700002306516700002106539700001806560700002806578700003406606700002406640700002106664700001806685700002006703700003206723700002606755700002706781700002906808700003106837700002106868700002306889700002506912700002106937700002306958700002506981700001607006856006207022 2018 eng d00aBioTIME: A database of biodiversity time series for the Anthropocene0 aBioTIME A database of biodiversity time series for the Anthropoc c07/2018 a760-7860 v273 a

Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.

Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.

Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1,000,000,000,000 cm2). Time period and grain BioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.

Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.

Software format: .csv and .SQL.

10abiodiversity10aglobal10aspatial10aspecies richness10atemporal10aturnover1 aDornelas, Maria1 aAntão, Laura, H.1 aMoyes, Faye1 aBates, Amanda, E.1 aMagurran, Anne, E.1 aAdam, Dušan1 aAkhmetzhanova, Asem, A.1 aAppeltans, Ward1 aArcos, José, Manuel1 aArnold, Haley1 aAyyappan, Narayanan1 aBadihi, Gal1 aBaird, Andrew, H.1 aBarbosa, Miguel1 aBarreto, Tiago, Egydio1 aBässler, Claus1 aBellgrove, Alecia1 aBelmaker, Jonathan1 aBenedetti-Cecchi, Lisandro1 aBett, Brian, J.1 aBjorkman, Anne, D.1 aBłażewicz, Magdalena1 aBlowes, Shane, A.1 aBloch, Christopher, P.1 aBonebrake, Timothy, C.1 aBoyd, Susan1 aBradford, Matt1 aBrooks, Andrew, J.1 aBrown, James, H.1 aBruelheide, Helge1 aBudy, Phaedra1 aCarvalho, Fernando1 aCastañeda-Moya, Edward1 aChen, Chaolun, Allen1 aChamblee, John, F.1 aChase, Tory, J.1 aCollier, Laura, Siegwart1 aCollinge, Sharon, K.1 aCondit, Richard1 aCooper, Elisabeth, J.1 aCornelissen, Hans, C.1 aCotano, Unai1 aCrow, Shannan, Kyle1 aDamasceno, Gabriella1 aDavies, Claire, H.1 aDavis, Robert, A.1 aDay, Frank, P.1 aDegraer, Steven1 aDoherty, Tim, S.1 aDunn, Timothy, E.1 aDurigan, Giselda1 aDuffy, Emmett1 aEdelist, Dor1 aEdgar, Graham, J.1 aElahi, Robin1 aElmendorf, Sarah, C.1 aEnemar, Anders1 aErnest, S., K. Morgan1 aEscribano, Rubén1 aEstiarte, Marc1 aEvans, Brian, S.1 aFan, Tung-Yung1 aFarah, Fabiano, Turini1 aFernandes, Luiz, Loureiro1 aFarneda, Fábio, Z.1 aFidelis, Alessandra1 aFitt, Robert1 aFosaa, Anna, Maria1 aFranco, Geraldo, Antonio Da1 aFrank, Grace, E.1 aFraser, William, R.1 aGarcía, Hernando1 aGatti, Roberto, Cazzolla1 aGivan, Or1 aGorgone-Barbosa, Elizabeth1 aGould, William, A.1 aGries, Corinna1 aGrossman, Gary, D.1 aGutierréz, Julio, R.1 aHale, Stephen1 aHarmon, Mark, E.1 aHarte, John1 aHaskins, Gary1 aHenshaw, Donald, L.1 aHermanutz, Luise1 aHidalgo, Pamela1 aHiguchi, Pedro1 aHoey, Andrew1 aVan Hoey, Gert1 aHofgaard, Annika1 aHoleck, Kristen1 aHollister, Robert, D.1 aHolmes, Richard1 aHoogenboom, Mia1 aHsieh, Chih-hao1 aHubbell, Stephen, P.1 aHuettmann, Falk1 aHuffard, Christine, L.1 aHurlbert, Allen, H.1 aIvanauskas, Natália, Macedo1 aJaník, David1 aJandt, Ute1 aJażdżewska, Anna1 aJohannessen, Tore1 aJohnstone, Jill1 aJones, Julia1 aJones, Faith, A. M.1 aKang, Jungwon1 aKartawijaya, Tasrif1 aKeeley, Erin, C.1 aKelt, Douglas, A.1 aKinnear, Rebecca1 aKlanderud, Kari1 aKnutsen, Halvor1 aKoenig, Christopher, C.1 aKortz, Alessandra, R.1 aKrál, Kamil1 aKuhnz, Linda, A.1 aKuo, Chao-Yang1 aKushner, David, J.1 aLaguionie-Marchais, Claire1 aLancaster, Lesley, T.1 aLee, Cheol, Min1 aLefcheck, Jonathan, S.1 aLévesque, Esther1 aLightfoot, David1 aLloret, Francisco1 aLloyd, John, D.1 aLópez-Baucells, Adrià1 aLouzao, Maite1 aMadin, Joshua, S.1 aMagnússon, Borgþór1 aMalamud, Shahar1 aMatthews, Iain1 aMcFarland, Kent, P.1 aMcGill, Brian1 aMcKnight, Diane, M.1 aMcLarney, William, O.1 aMeador, Jason1 aMeserve, Peter, L.1 aMetcalfe, Daniel, J.1 aMeyer, Christoph, F. J.1 aMichelsen, Anders1 aMilchakova, Nataliya1 aMoens, Tom1 aMoland, Even1 aMoore, Jon1 aMoreira, Carolina, Mathias1 aMüller, Jörg1 aMurphy, Grace1 aMyers-Smith, Isla, H.1 aMyster, Randall, W.1 aNaumov, Andrew1 aNeat, Francis1 aNelson, James, A.1 aNelson, Michael, Paul1 aNewton, Stephen, F.1 aNorden, Natalia1 aOliver, Jeffrey, C.1 aOlsen, Esben, M.1 aOnipchenko, Vladimir, G.1 aPabis, Krzysztof1 aPabst, Robert, J.1 aPaquette, Alain1 aPardede, Sinta1 aPaterson, David, M.1 aPélissier, Raphaël1 aPeñuelas, Josep1 aPérez-Matus, Alejandro1 aPizarro, Oscar1 aPomati, Francesco1 aPost, Eric1 aPrins, Herbert, H. T.1 aPriscu, John, C.1 aProvoost, Pieter1 aPrudic, Kathleen, L.1 aPulliainen, Erkki1 aRamesh, B., R.1 aRamos, Olivia, Mendivil1 aRassweiler, Andrew1 aRebelo, Jose, Eduardo1 aReed, Daniel, C.1 aReich, Peter, B.1 aRemillard, Suzanne, M.1 aRichardson, Anthony, J.1 aRichardson, Paul1 avan Rijn, Itai1 aRocha, Ricardo1 aRivera-Monroy, Victor, H.1 aRixen, Christian1 aRobinson, Kevin, P.1 aRodrigues, Ricardo, Ribeiro1 aRossa-Feres, Denise, de Cerquei1 aRudstam, Lars1 aRuhl, Henry1 aRuz, Catalina, S.1 aSampaio, Erica, M.1 aRybicki, Nancy1 aRypel, Andrew1 aSal, Sofia1 aSalgado, Beatriz1 aSantos, Flavio, A. M.1 aSavassi-Coutinho, Ana, Paula1 aScanga, Sara1 aSchmidt, Jochen1 aSchooley, Robert1 aSetiawan, Fakhrizal1 aShao, Kwang-Tsao1 aShaver, Gaius, R.1 aSherman, Sally1 aSherry, Thomas, W.1 aSiciński, Jacek1 aSievers, Caya1 ada Silva, Ana, Carolina1 ada Silva, Fernando, Rodrigues1 aSilveira, Fabio, L.1 aSlingsby, Jasper1 aSmart, Tracey1 aSnell, Sara, J.1 aSoudzilovskaia, Nadejda, A.1 aSouza, Gabriel, B. G.1 aSouza, Flaviana, Maluf1 aSouza, Vinícius, Castro1 aStallings, Christopher, D.1 aStanforth, Rowan1 aStanley, Emily, H.1 aSterza, José, Mauro1 aStevens, Maarten1 aStuart-Smith, Rick1 aSuarez, Yzel, Rondon1 aSupp, Sarah uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/geb.1272901630nas a2200169 4500008004100000245008200041210006900123260001200192490000600204520109200210100002201302700002401324700002101348700001701369700001601386856005801402 2018 eng d00aDrivers of solar radiation variability in the McMurdo Dry Valleys, Antarctica0 aDrivers of solar radiation variability in the McMurdo Dry Valley c03/20180 v83 a

 

Annually averaged solar radiation in the McMurdo Dry Valleys, Antarctica has varied by over 20 W m−2 during the past three decades; however, the drivers of this variability are unknown. Because small differences in radiation are important to water availability and ecosystem functioning in polar deserts, determining the causes are important to predictions of future desert processes. We examine the potential drivers of solar variability and systematically eliminate all but stratospheric sulfur dioxide. We argue that increases in stratospheric sulfur dioxide increase stratospheric aerosol optical depth and decrease solar intensity. Because of the polar location of the McMurdo Dry Valleys (77–78°S) and relatively long solar ray path through the stratosphere, terrestrial solar intensity is sensitive to small differences in stratospheric transmissivity. Important sources of sulfur dioxide include natural (wildfires and volcanic eruptions) and anthropogenic emission.

 

1 aObryk, Maciek, K.1 aFountain, Andrew, G1 aDoran, Peter, T.1 aLyons, Berry1 aEastman, R. uhttp://www.nature.com/articles/s41598-018-23390-7.pdf02633nas a2200133 4500008004100000245016300041210006900204260005700273490000900330520205900339100002202398700002102420856005802441 2018 eng d00aGroundwater and thermal legacy of a large paleolake in Taylor Valley, East Antarctica as evidenced by airborne electromagnetic and sedimentological techniques0 aGroundwater and thermal legacy of a large paleolake in Taylor Va aBaton Rouge, LAbLouisiana State Universityc07/20180 vM.S.3 a

During the Last Glacial Maximum, grounded ice in the Ross Sea extended into the otherwise ice-free McMurdo Dry Valleys, creating a series of large ice dammed paleolakes. Grounded ice within the mouth of Taylor Valley allowed for lake levels to reach elevations not possible at modern day and formed what is known as Glacial Lake Washburn (GLW). GLW extended from the eastern portion of Taylor Valley roughly 20 km west to a level ~300 m higher than modern day Lake Fryxell. The formation and existence of GLW has been debated, though previous studies correlate the timing of GLW with early Holocene grounded ice. Evidence of GLW has largely been constrained to the interpretation of glacial deposits and fluvial features such as lacustrine deposits, strandlines, and preserved paleodeltas. GIS and remote sensing techniques paired with regional resistivity data provide new insight into the paleohydrology of the region.

To quantify the extent of GLW, paleodelta locations were mapped using high resolution LiDAR digital elevation models and satellite imagery. Delta topset elevations were correlated between three streams in Fryxell basin to determine paleolake levels. Additionally, mean resistivity maps generated from airborne electromagnetic survey data (SkyTEM) reveal an extensive groundwater system within Fryxell basin which is interpreted as a legacy groundwater signal from GLW. Resistivity data suggests that active permafrost formation has been ongoing since onset of lake drainage, and that lake levels were over 60 m higher than modern only 1,000 – 2,000 yr BP. This coincides with a warmer than modern paleoclimate inferred by ice core records, indicating a dynamic hydrological system that is highly sensitive to small changes in climate. As global temperatures increase, Lake Fryxell will continue to experience highly variable lake levels. Lakes and groundwater within the McMurdo Dry Valleys are critical to understanding impacts on the broader ecosystem which is largely driven by the availability of liquid water.

1 aMyers, Krista, F.1 aDoran, Peter, T. uhttps://digitalcommons.lsu.edu/gradschool_theses/477602508nas a2200181 4500008004100000245017000041210006900211260001200280300001600292490000700308520183400315100002302149700002102172700002202193700002302215700002102238856006702259 2018 eng d00aThe physical limnology of a permanently ice-covered and chemically stratified Antarctic lake using high resolution spatial data from an autonomous underwater vehicle0 aphysical limnology of a permanently icecovered and chemically st c05/2018 a1234 - 12520 v633 a

We used an Environmentally Non-Disturbing Under-ice Robotic ANtarctic Explorer to make measurements of conductivity and temperature in Lake Bonney, a chemically stratified, permanently ice-covered Antarctic lake that abuts Taylor Glacier, an outlet glacier from the Polar Plateau. The lake is divided into two lobes – East Lobe Bonney (ELB) and West Lobe Bonney (WLB), each with unique temperature and salinity profiles. Most of our data were collected in November 2009 from WLB to examine the influence of the Taylor Glacier on the structure of the water column. Temperatures adjacent to the glacier face between 20 m and 22 m were 38C colder than in the rest of WLB, due to latent heat transfer associated with melting of the submerged glacier face and inflow of cold brines that originate beneath the glacier. Melting of the glacier face into the salinity gradient below the chemocline generates a series of nearly horizontal intrusions into WLB that were previously documented in profiles measured with 3 cm vertical resolution in 1990–1991. WLB and ELB are connected by a narrow channel through which water can be exchanged over a shallow sill that controls the position of the chemocline in WLB. A complex exchange flow appears to exist through the narrows, driven by horizontal density gradients and melting at the glacier face. Superimposed on the exchange is a net west- to-east flow generated by the higher volume of meltwater inflows to WLB. Both of these processes can be expected to be enhanced in the future as more meltwater is produced. 

1 aSpigel, Robert, H.1 aPriscu, John, C.1 aObryk, Maciek, K.1 aStone, William, C.1 aDoran, Peter, T. uhttp://onlinelibrary.wiley.com/wol1/doi/10.1002/lno.10768/full00851nas a2200265 4500008004100000245009100041210006900132260001200201300001400213490000600227100002500233700002200258700001700280700002100297700002400318700001700342700002400359700002100383700002000404700003300424700003100457700002300488700002000511856005400531 2017 eng d00aDecadal ecosystem response to an anomalous melt season in a polar desert in Antarctica0 aDecadal ecosystem response to an anomalous melt season in a pola c09/2017 a1334-13380 v11 aGooseff, Michael, N.1 aBarrett, John, E.1 aAdams, Byron1 aDoran, Peter, T.1 aFountain, Andrew, G1 aLyons, Berry1 aMcKnight, Diane, M.1 aPriscu, John, C.1 aSokol, Eric, R.1 aTakacs-Vesbach, Cristina, D.1 aVandegehuchte, Martijn, L.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://www.nature.com/articles/s41559-017-0253-002279nas a2200133 4500008004100000245013700041210006900178260004800247490000900295520174300304100001902047700002102066856005802087 2017 eng d00aEvidence of subglacial brine inflow and wind-induced mixing from high resolution temperature measurements in Lake Bonney, Antarctica0 aEvidence of subglacial brine inflow and windinduced mixing from  aBaton Rouge, LAbLouisiana State University0 vM.S.3 a

Hypersaline brine beneath Taylor Glacier enters proglacial West Lobe Lake Bonney (WLB) subglacially as well as from Blood Falls, a surface discharge point at the Taylor Glacier terminus. The brine strongly influences the water column of WLB. Because of the extremely high salinities below the chemocline in WLB, density is determined almost entirely by salinity and temperature can be used as a passive tracer. Cold brine intrusions enter WLB at the glacier face and intrude in to the water column at the depth of neutral buoyancy, where they can be identified by anomalously cold temperatures at that depth. This study is the first to definitively identify subglacial brine intrusions in WLB, since the absence of an open water moat in the winter prevents brine entry from the surface at Blood Falls. High resolution thermistors and CTDs deployed year-round beneath the perennial ice cover demonstrate that brine intrusions can influence the thermal stratification of the water column near the glacier terminus for the majority of the year, and that the effects diminish with distance from the glacier terminus. High volumes of brine inflow alter the density stratification of the water column at the depth of the intrusion and cause turbulent mixing near the glacier terminus. High resolution measurements also reveal internal water movements associated with katabatic wind events, a novel finding that challenges long held assumptions about the stability of the WLB water column. The long term records of Blood Falls flow and of temperature anomalies in WLB indicate that brine release from the subglacial system has been a persistent feature in the region for decades, with implications for the geochemistry and biology of WLB.

1 aLawrence, Jade1 aDoran, Peter, T. uhttps://digitalcommons.lsu.edu/gradschool_theses/434300637nas a2200157 4500008004100000245015300041210007000194260001200264300001200276490000700288100002200295700002100317700002100338700002700359856009300386 2017 eng d00aThe influence of föhn winds on Glacial Lake Washburn and palaeotemperatures in the McMurdo Dry Valleys, Antarctica, during the Last Glacial Maximum0 ainfluence of föhn winds on Glacial Lake Washburn and palaeotempe c10/2017 a457-4670 v291 aObryk, Maciek, K.1 aDoran, Peter, T.1 aWaddington, E.D.1 aMcKay, Christopher, P. uhttps://www.cambridge.org/core/product/identifier/S0954102017000062/type/journal_article03009nas a2200133 4500008004100000245011500041210006900156260002600225490000900251520251000260100002102770700001702791856006702808 2017 eng d00aSpatial and Temporal Geochemical Characterization of Aeolian Material from the McMurdo Dry Valleys, Antarctica0 aSpatial and Temporal Geochemical Characterization of Aeolian Mat bOhio State University0 vM.S.3 a

Aeolian processes play an important role in the transport of both geological and biological materials globally, on the biogeochemistry of ecosystems, and in landscape evolution. As the largest ice free area on the Antarctic continent (approximately 4800 km2), the McMurdo Dry Valleys (MDV) are potentially a major source of aeolian material for Antarctica, but information on the spatial and temporal variability of this material is needed to understand its soluble and bulk geochemistry, deposition and source, and hence influence on ecosystem dynamics. 53 samples of aeolian material from Alatna Valley, Victoria Valley, Miers Valley, and Taylor Valley (Taylor Glacier, East Lake Bonney, F6 (Lake Fryxell), and Explorer’s Cove) were collected at five heights (5, 10, 20, 50, 100 cm) above the surface seasonally for 2013 through 2015. The sediment was analyzed for soluble solids, total and organic carbon, minerology, and bulk chemistry. Of the soluble component, the major anions varied between Cl- and HCO3-, and the major cation was Na+ for all sites. Soluble N:P ratios in the aeolian material reflect nutrient limitations seen in MDV soils, where younger, coastal soils are N-limited, while older, up valley soils are P-limited. Material from East Lake Bonney was P-limited in the winter samples, but N-limited in the full year samples, suggesting different sources of material based on season. Analysis of soluble salts in aeolian material in Taylor Valley compared to published soil literature demonstrates a primarily down valley transport of materials from Taylor Glacier towards the coast. The bulk chemistry suggests that the aeolian material is highly unweathered (CIA values less than 60 %), but scanning electron microscope images show alteration for some individual sediment grains. The mineralogy was reflective of local rocks, specifically the McMurdo Volcanics, Ferrar Dolerite, Beacon Sandstone and granite, but variations in major oxide percentages and rare earth element signatures could not be explained by mixing lines between these four rock types. This potentially suggests that there may be an additional, and possibly distant, source of aeolian material to the MDV that is not accounted for. This work provides the first fully elevated spatial and temporal analysis of the geochemistry of aeolian material from the Dry Valleys, and contributes to a better understanding of sediment provenance and how aeolian deposition may affect surface biological communities.

1 aDiaz, Melisa, A.1 aLyons, Berry uhttp://rave.ohiolink.edu/etdc/view?acc_num=osu150046821614772502451nas a2200193 4500008004100000245011100041210006900152260001200221300001400233490000700247520180200254100002402056700002302080700002102103700002502124700002002149700002402169856006402193 2017 eng d00aThermal autecology describes the occurrence patterns of four benthic diatoms in McMurdo Dry Valley streams0 aThermal autecology describes the occurrence patterns of four ben c06/2017 a2381-23960 v403 a

Benthic microbial mats in the glacial-fed melt- water streams are hotspots of productivity in the McMurdo Dry Valleys (MDV), Antarctica. Benthic diatoms are common in these mats and the[45 primarily endemic taxa represent the most diverse group of eukaryotes in the MDV. In this harsh polar desert, streams are thermally dynamic with daily water temperatures varying 6–9 °C and daily maximum temperatures as high as 15 °C. Stream temperature may play a role in determining growth rates and survival strategies. To understand taxon-specific adaptations to their environment, we measured the growth rates of unialgal cultures of four diatom taxa (Psammothidium papilio, Hantzschia abundans, Hantzschia amphioxys, and Hantzschia amphioxys f. muelleri) under three temperature conditions (7.6, 10, and 15 °C) that were representative of maximum daily stream temperatures. We found that P. papilio exhibited a constant growth rate across the full temperature range; this species is most common in streams that begin to flow early in the summer and with less variable thermal regimes. Growth rates for H. abundans were greatest at 15 °C, but showed a non-linear relationship with temperature. H. amphioxys f. muelleri

grew faster than the other taxa studied and thrived at 10 °C. Hantzschia amphioxys grew only at the two lower temperatures. These results aligned with the observed relationships between each taxon’s relative abundance and stream temperatures in the long-term record maintained by the MDV Long-Term Ecological Research program. Overall, our observations suggest that differences in thermal optima may be one factor contributing to and maintaining the diversity of benthic diatom flora in the MDV.
1 aDarling, Joshua, P.1 aGarland, Deena, D.1 aStanish, Lee, F.1 aEsposito, Rhea, M.M.1 aSokol, Eric, R.1 aMcKnight, Diane, M. uhttps://link.springer.com/article/10.1007/s00300-017-2151-y01407nas a2200445 4500008004100000245007700041210006900118260001200187490005900199100002200258700002400280700001900304700002100323700002100344700001900365700002400384700002000408700001700428700002400445700001700469700002300486700001900509700002100528700002000549700002100569700002200590700002300612700002500635700001800660700002200678700002300700700002300723700002500746700001800771700002000789700002400809700002600833700002500859856007700884 2016 eng d00aAerobiology Over Antarctica – A New Initiative for Atmospheric Ecology0 aAerobiology Over Antarctica A New Initiative for Atmospheric Eco c02/20160 v7767961946103149272350113651344451428464791101239365741 aPearce, David, A.1 aAlekhina, Irina, A.1 aTerauds, Aleks1 aWilmotte, Annick1 aQuesada, Antonio1 aEdwards, Arwyn1 aDommergue, Aurelien1 aSattler, Birgit1 aAdams, Byron1 aMagalhaes, Catarina1 aChu, Wan-Loy1 aLau, Maggie, C. Y.1 aCary, Craig, S1 aSmith, David, J.1 aWall, Diana, H.1 aEguren, Gabriela1 aMatcher, Gwynneth1 aBradley, James, A.1 ade Vera, Jean-Pierre1 aElster, Josef1 aHughes, Kevin, A.1 aCuthbertson, Lewis1 aBenning, Liane, G.1 aGunde-Cimerman, Nina1 aConvey, Peter1 aHong, Soon, Gyu1 aPointing, Steve, B.1 aPellizari, Vivian, H.1 aVincent, Warwick, F. uhttp://journal.frontiersin.org/Article/10.3389/fmicb.2016.00016/abstract01022nas a2200289 4500008004100000245010700041210006900148260001200217300001400229490000700243100002800250700002200278700002500300700001900325700002000344700002700364700002500391700002600416700002300442700001700465700001900482700002000501700002100521700001800542700002100560856015100581 2016 eng d00aBiogeochemistry and microbial diversity in the marine cavity beneath the McMurdo Ice Shelf, Antarctica0 aBiogeochemistry and microbial diversity in the marine cavity ben c11/2015 a572 - 5860 v611 aVick-Majors, Trista, J.1 aAchberger, Amanda1 aSantibáñez, Pamela1 aDore, John, E.1 aHodson, Timothy1 aMichaud, Alexander, B.1 aChristner, Brent, C.1 aAi, Jill., Mikucki Ji1 aSkidmore, Mark, L.1 aPowell, Ross1 aAdkins, Peyton1 aBarbante, Carlo1 aMitchell, Andrew1 aScherer, Reed1 aPriscu, John, C. uhttp://doi.wiley.com/10.1002/lno.v61.2http://doi.wiley.com/10.1002/lno.10234http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Flno.1023401706nas a2200145 4500008004100000245009500041210006900136260001200205520122100217100001901438700001901457700001401476700002401490856004601514 2016 eng d00aDissolved black carbon in Antarctic lakes: chemical signatures of past and present sources0 aDissolved black carbon in Antarctic lakes chemical signatures of c06/20163 a

The perennially ice-covered, closed-basin lakes in the McMurdo Dry Valleys, Antarctica, serve as sentinels for understanding the fate of dissolved black carbon from glacial sources in aquatic ecosystems. Here we show that dissolved black carbon can persist in freshwater and saline surface waters for thousands of years, while preserving the chemical signature of the original source materials. The ancient brines of the lake bottom waters have retained dissolved black carbon with a woody chemical signature, representing long-range transport of black carbon from wildfires. In contrast, the surface waters are enriched in contemporary black carbon from fossil fuel combustion. Comparison of samples collected 25 years apart from the same lake suggests that the enrichment in anthropogenic black carbon is recent. Differences in the chemical composition of dissolved black carbon among the lakes are likely due to biogeochemical processing such as photochemical degradation and sorption on metal oxides.

1 aKhan, Alia, L.1 aJaffé, Rudolf1 aDing, Yan1 aMcKnight, Diane, M. uhttp://doi.wiley.com/10.1002/2016GL06860902953nas a2200169 4500008004100000245010500041210006900146260001200215300001400227490000700241520241100248100001502659700002302674700002202697700002102719856004302740 2016 eng d00aGrowth dynamics of a laminated microbial mat in response to variable irradiance in an Antarctic lake0 aGrowth dynamics of a laminated microbial mat in response to vari c02/2016 a396 - 4100 v613 a
  1. Laminated microbial mats are important ecosystem components of perennially ice-covered Antarctic dry valley lakes. In order to understand better their response to changing environment, we made observations and carried out a manipulation experiment to determine their response to variations in irradiance in Lake Hoare (77°38′ S, 162°53′ E).
  2. Ice transparency was the most variable parameter that affected benthic light dose, both spatially and between years. Patterns of lamina accrual corresponded to irradiance history, with laminae that were initiated in high transmission years thicker than those from low transmission years.
  3. A shading experiment confirmed that accrual of lamina thickness, calcite precipitation and ash-free dry mass were determined by irradiance, but photosynthetic biomass and phototrophic species composition were less affected.
  4. Buried laminae decomposed only slowly over time, with potentially viable phototrophs many laminae down into the microbial mat. Decay rate increased only slightly with shading.
  5. We conclude that the microbial mats in Lake Hoare are characterised by remarkable stability, with slow accumulation rates and turnover of biomass over time. Photosynthetic biomass and species composition appeared to be stable across long time periods, with interannual variation in lamination pattern due to differential accumulation of extracellular polysaccharide and representing the visible expression of annual growth conditions.
1 aHawes, Ian1 aJungblut, Anne, D.1 aObryk, Maciek, K.1 aDoran, Peter, T. uhttp://doi.wiley.com/10.1111/fwb.1271500649nas a2200169 4500008004100000022001400041245017800055210006900233260001200302300001600314490000700330100002200337700002300359700002200382700002100404856005400425 2016 eng d a0016-803300aHigh-resolution ground-penetrating radar profiles of perennial lake ice in the McMurdo Dry Valleys, Antarctica: Horizon attributes, unconformities, and subbottom penetration0 aHighresolution groundpenetrating radar profiles of perennial lak c01/2016 aWA13 - WA200 v811 aDugan, Hilary, A.1 aArcone, Steven, A.1 aObryk, Maciek, K.1 aDoran, Peter, T. uhttp://library.seg.org/doi/10.1190/geo2015-0159.101797nas a2200253 4500008004100000022001400041245007900055210006900134260001200203300001400215490000700229520101000236100002401246700001601270700001701286700002101303700002001324700002501344700002201369700002101391700002801412700002301440856008001463 2016 eng d a0006-356800aThe Impact of a Large-Scale Climate Event on Antarctic Ecosystem Processes0 aImpact of a LargeScale Climate Event on Antarctic Ecosystem Proc c10/2016 a848 - 8630 v663 a

Extreme climate and weather events, such as a drought, hurricanes, or ice storms, can strongly imprint ecosystem processing and may alter ecosystem structure. Ecosystems in extreme environments are particularly vulnerable because of their adaptation to severe limitations in energy, water, or nutrients. The vulnerability can be expressed as a relatively long-lasting ecosystem response to a small or brief change in environmental conditions. Such an event occurred in Antarctica and affected two vastly different ecosystems: a marine-dominated coastal system and a terrestrial polar desert. Both sites experienced winds that warmed air temperatures above the 0°C threshold, resulting in extensive snow and ice melt and triggering a series of cascading effects through the ecosystems that are continuing to play out more than a decade later. This highlights the sensitivity of Antarctic ecosystems to warming events, which should occur more frequently in the future with global climate warming.

1 aFountain, Andrew, G1 aSaba, Grace1 aAdams, Byron1 aDoran, Peter, T.1 aFraser, William1 aGooseff, Michael, N.1 aObryk, Maciek, K.1 aPriscu, John, C.1 aStammerjohn, Sharon, E.1 aVirginia, Ross, A. uhttp://academic.oup.com/bioscience/article-pdf/66/10/848/7510601/biw110.pdf00845nas a2200193 4500008004100000022001400041245014300055210006900198260001600267300001400283490000700297100002100304700002800325700002900353700003300382700002200415700002100437856019300458 2016 eng d a0006-356800aMicrobial Community Dynamics in Two Polar Extremes: The Lakes of the McMurdo Dry Valleys and the West Antarctic Peninsula Marine Ecosystem0 aMicrobial Community Dynamics in Two Polar Extremes The Lakes of  cJan-10-2016 a829 - 8470 v661 aBowman, Jeff, S.1 aVick-Majors, Trista, J.1 aMorgan-Kiss, Rachael, M.1 aTakacs-Vesbach, Cristina, D.1 aDucklow, Hugh, W.1 aPriscu, John, C. uhttps://academic.oup.com/bioscience/article-lookup/doi/10.1093/biosci/biw103https://academic.oup.com/bioscience/article/66/10/829/2236137/Microbial-Community-Dynamics-in-Two-Polar-Extremes00761nas a2200241 4500008004100000022001400041245009900055210006900154260001200223300001400235490000700249100002300256700001500279700002200294700001800316700002100334700002100355700002400376700001900400700002700419700001800446856005500464 2016 eng d a0099-224000aMicrobial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake0 aMicrobial Mat Communities along an Oxygen Gradient in a Perennia c01/2016 a620 - 6300 v821 aJungblut, Anne, D.1 aHawes, Ian1 aMackey, Tyler, J.1 aKrusor, Megan1 aDoran, Peter, T.1 aSumner, Dawn, Y.1 aEisen, Jonathan, A.1 aHillman, Colin1 aGoroncy, Alexander, K.1 aStams, A., J. uhttp://aem.asm.org/lookup/doi/10.1128/AEM.02699-1502208nas a2200181 4500008004100000022001400041245010400055210006900159260001200228300001100240520160100251100002201852700002101874700001801895700002701913700002101940856006501961 2016 eng d a0022-143000aModeling the thickness of perennial ice covers on stratified lakes of the Taylor Valley, Antarctica0 aModeling the thickness of perennial ice covers on stratified lak c06/2016 a1 - 103 a
A 1-D ice cover model was developed to predict and constrain drivers of long-term ice thickness trends in chemically stratified lakes of Taylor Valley, Antarctica. The model is driven by surface radiative heat fluxes and heat fluxes from the underlying water column. The model successfully reproduced 16 a (between 1996 and 2012) of ice thickness changes for the west lobe of Lake Bonney (average ice thickness = 3.53 m) and Lake Fryxell (average ice thickness = 4.22 m). Long-term ice thickness trends require coupling with the thermal structure of the water column. The heat stored within the temperature maximum of lakes exceeding a liquid water column depth of 20 m can either impede or facilitate ice thickness change depending on the predominant climatic trend (cooling or warming). As such, shallow (<20 m deep water columns) perennially ice-covered lakes without deep temperature maxima are more sensitive indicators of climate change. The long-term ice thickness trends are a result of surface energy flux and heat flux from the deep temperature maximum in the water column, the latter of which results from absorbed solar radiation.

 

1 aObryk, Maciek, K.1 aDoran, Peter, T.1 aHicks, J., A.1 aMcKay, Christopher, P.1 aPriscu, John, C. uhttp://www.journals.cambridge.org/abstract_S002214301600069101330nas a2200193 4500008004100000245009800041210006900139260004000208490000900248520071900257653001500976653001400991653001501005653001701020653001901037100002101056700002101077856003801098 2016 eng d00aNoble Gas Radioisotope Constraints on Water Residence Time and Solvent Sources in Lake Bonney0 aNoble Gas Radioisotope Constraints on Water Residence Time and S aChicago, ILbUniversity of Illinois0 vM.S.3 a

A noble gas radionuclide analysis of perennially ice covered West Lake Bonney was performed in order to determine water residence time and ice cover timing. Bulk gas samples were collected at four depths in the lake. Krypton and argon gases were selectively isolated from the bulk gas and measurements of 81Kr, 85Kr and 39Ar were made. Radiokrypton and radioargon analyses yielded lower limit ages of 78 to 285 years, significantly younger than expected based on previous dating efforts. It was determined that these new data do not invalidate previous work, but instead offer new insight into the timing of the most recent episode of direct communication between the atmosphere and West Lake Bonney waters.

10aAntarctica10anoble gas10aradioargon10aradiokrypton10aresidence time1 aCronin, Kyle, D.1 aDoran, Peter, T. uhttp://hdl.handle.net/10027/2157002591nas a2200193 4500008004100000245013100041210006900172260001200241300001100253490000700264520191200271100002202183700002402205700002402229700003302253700002402286700001702310856007002327 2016 eng d00aNutrient treatments alter microbial mat colonization in two glacial meltwater streams from the McMurdo Dry Valleys, Antarctica0 aNutrient treatments alter microbial mat colonization in two glac c03/2016 afiw0490 v923 a

Microbial mats are abundant in many alpine and polar aquatic ecosystems. With warmer temperatures, new hydrologic pathways are developing in these regions and increasing dissolved nutrient fluxes. In the McMurdo Dry Valleys, thermokarsting may release both nutrients and sediment, and has the potential to influence mats in glacial meltwater streams. To test the role of nutrient inputs on community structure, we created nutrient diffusing substrata (NDS) with agar enriched in N, P and N + P, with controls, and deployed them into two Dry Valley streams. We found N amendments (N and N + P) to have greater chlorophyll-a concentrations, total algal biovolume, more fine filamentous cyanobacteria and a higher proportion of live diatoms than other treatments. Furthermore, N treatments were substantially elevated in Bacteroidetes and the small diatom, Fistulifera pelliculosa. On the other hand, species richness was almost double in P and N + P treatments over others, and coccoid green algae and Proteobacteria were more abundant in both streams. Collectively, these data suggest that nutrients have the potential to stimulate growth and alter community structure in glacial meltwater stream microbial mats, and the recent erosion of permafrost and accelerated glacial melt will likely impact resident biota in polar lotic systems here and elsewhere.

1 aKohler, Tyler, J.1 aVan Horn, David, J.1 aDarling, Joshua, P.1 aTakacs-Vesbach, Cristina, D.1 aMcKnight, Diane, M.1 aWagner, Dirk uhttp://femsec.oxfordjournals.org/lookup/doi/10.1093/femsec/fiw04900836nas a2200229 4500008004100000245007200041210006900113260001600182490000600198100002800204700002100232700002200253700002500275700001900300700002700319700002200346700002400368700002300392700002100415710002900436856014100465 2016 eng d00aPhysiological Ecology of Microorganisms in Subglacial Lake Whillans0 aPhysiological Ecology of Microorganisms in Subglacial Lake Whill cMar-10-20180 v71 aVick-Majors, Trista, J.1 aMitchell, Andrew1 aAchberger, Amanda1 aChristner, Brent, C.1 aDore, John, E.1 aMichaud, Alexander, B.1 aMikucki, Jill, A.1 aPurcell, Alicia, M.1 aSkidmore, Mark, L.1 aPriscu, John, C.1 aThe WISSARD Science Team uhttp://journal.frontiersin.org/article/10.3389/fmicb.2016.01705/fullhttp://journal.frontiersin.org/article/10.3389/fmicb.2016.01705/full00943nas a2200253 4500008004100000022001400041245008700055210006900142260001600211300001400227490000700241100002200248700002100270700002600291700002500317700001200342700002900354700002100383700002100404700002800425700002700453700002200480856018700502 2016 eng d a0006-356800aResponses of Antarctic Marine and Freshwater Ecosystems to Changing Ice Conditions0 aResponses of Antarctic Marine and Freshwater Ecosystems to Chang cJan-10-2016 a864 - 8790 v661 aObryk, Maciek, K.1 aDoran, Peter, T.1 aFriedlaender, Ari, S.1 aGooseff, Michael, N.1 aLi, Wei1 aMorgan-Kiss, Rachael, M.1 aPriscu, John, C.1 aSchofield, Oscar1 aStammerjohn, Sharon, E.1 aSteinberg, Deborah, K.1 aDucklow, Hugh, W. uhttps://academic.oup.com/bioscience/article-lookup/doi/10.1093/biosci/biw109https://academic.oup.com/bioscience/article/66/10/864/2415532/Responses-of-Antarctic-Marine-and-Freshwater03338nas a2200193 4500008004100000022001400041245010600055210006900161260001600230300001400246490000600260520270300266100002102969700002302990700002503013700002603038700002703064856005303091 2015 eng d a1752-089400aAccumulation and marine forcing of ice dynamics in the western Ross Sea during the last deglaciation0 aAccumulation and marine forcing of ice dynamics in the western R cJan-07-2016 a625 - 6280 v83 a

The grounding line of the ice sheet in the Ross Sea, Antarctica, retreated between the Last Glacial Maximum and the present. However, the timing of the retreat and the interplay of factors controlling ice stability in this region1 remain uncertain. Here we use 180 radiocarbon dates to reconstruct the chronology of moraine construction on the headlands adjacent to western McMurdo Sound. On the basis of these dates we then assess the timing of ice expansion and retreat in the Ross drainage system that is fed from both the East and West Antarctic ice sheets. We find that grounded ice in the western Ross Sea achieved its greatest thickness and extent during the last termination, between 12,800 and 18,700 years ago. Maximum ice thickness at our site coincides with a period of high accumulation as recorded by the West Antarctic Ice Sheet Divide ice core2. Recession of the ice sheet from the headland moraines began about 12,800 years ago, despite continued high accumulation and the expansion of land-based glaciers at this time. We therefore suggest that the grounding-line retreat reflects an increased marine influence as sea levels rose and the ocean warmed. We suggest that future instability in the ice sheet grounding line may occur whenever the ocean forcing is stronger than forcing from accumulation.

 
 
1 aHall, Brenda, L.1 aDenton, George, H.1 aHeath, Stephanie, L.1 aJackson, Margaret, S.1 aKoffman, Tobias, N. B. uhttp://www.nature.com/doifinder/10.1038/ngeo247804921nas a2200181 4500008004100000022001400041245008200055210006900137260001200206300001300218520434700231100002104578700001504599700002204614700002304636700002104659856005904680 2015 eng d a0091-761300aAntarctic microbial mats: A modern analog for Archean lacustrine oxygen oases0 aAntarctic microbial mats A modern analog for Archean lacustrine  c10/2015 aG36966.13 a

The evolution of oxygenic photosynthesis was the most important geochemical event in

Earth history, causing the Great Oxidation Event (GOE) ~2.4 b.y. ago. However, evidence is mixed as to whether O2 production occurred locally as much as 2.8 b.y. ago, creating O2 oases, or initiated just prior to the GOE. The biogeochemical dynamics of possible O2 oases have been poorly constrained due to the absence of modern analogs. However, cyanobacteria in microbial mats in a perennially anoxic region of Lake Fryxell, Antarctica, create a 1–2 mm O2-containing layer in the upper mat during summer, providing the first known modern analog for formation of benthic O2 oases. In Lake Fryxell, benthic cyanobacteria are present below the oxycline in the lake. Mat photosynthesis rates were slow due to low photon flux rate (1–2 μmol m-2 s-1) under thick ice cover, but photosynthetic O2 production was sufficient to sustain up to 50 μmol O2 L-1, sandwiched between anoxic overlying water and anoxic sedi- ments. We hypothesize that Archean cyanobacteria could have similarly created O2 oases in benthic mats prior to the GOE. Analogous mats may have been at least partly responsible for geological evidence of oxidative weathering prior to the GOE, and habitats such as Lake Fryxell provide natural laboratories where the impact of benthic O2 oases on biogeochemical signatures can be investigated. 

 

1 aSumner, Dawn, Y.1 aHawes, Ian1 aMackey, Tyler, J.1 aJungblut, Anne, D.1 aDoran, Peter, T. uhttp://geology.gsapubs.org/lookup/doi/10.1130/G36966.103321nas a2200205 4500008004100000022001400041245008600055210006900141260001200210300001600222490000700238520262100245100001702866700002302883700002402906700002502930700001502955700002402970856012102994 2015 eng d a0091-761300aAntarctic streams as a potential source of iron for the Southern Ocean: Figure 1.0 aAntarctic streams as a potential source of iron for the Southern c11/2016 a1003 - 10060 v433 a

Due to iron’s role in oceanic primary production, there has been great interest in quantifying the importance of Fe in regions where concentrations are very low and macronutrients, nitrate and phosphate, are available. Measurements of filterable (i.e., <0.4 μm) Fe concentrations in streams from Taylor Valley, McMurdo Dry Valleys, Antarctica, suggest that coastal-zone stream Fe input to the Southern Ocean could potentially play an important role in primary production in nearshore regions. Filterable Fe (fFe) data from streams in the McMurdo Dry Valleys were used to represent glacier meltwater that flows through ice-free landscape with the potential of transporting Fe to the Antarctic coastal zone. Estimates of potential fFe flux to the Antarctic Peninsula region using our mean fFe concentration of 10.6 µg L–1 combined with an estimate of ice-free area for the Antarctic Peninsula result in an fFe flux of 1.2 × 107 g yr–1. Although small compared to iceberg and aeolian Fe fluxes, future stream input to the Southern Ocean could increase due to glacier retreat and 

1 aLyons, Berry1 aDailey, Kelsey, R.1 aWelch, Kathleen, A.1 aDeuerling, Kelly, M.1 aWelch, Sue1 aMcKnight, Diane, M. uhttp://geology.gsapubs.org/lookup/doi/10.1130/G36989.1http://geology.geoscienceworld.org/lookup/doi/10.1130/G36989.101657nas a2200229 4500008004100000245008700041210006900128260001600197300000900213490000600222520097300228100002201201700001401223700001601237700002301253700001701276700002201293700002101315700002201336700001401358856005501372 2015 eng d00aDeep groundwater and potential subsurface habitats beneath an Antarctic dry valley0 aDeep groundwater and potential subsurface habitats beneath an An cApr-04-2017 a68310 v63 aThe occurrence of groundwater in Antarctica, particularly in the ice-free regions and along the coastal margins is poorly understood. Here we use an airborne transient electromagnetic (AEM) sensor to produce extensive imagery of resistivity beneath Taylor Valley. Regional-scale zones of low subsurface resistivity were detected that are inconsistent with the high resistivity of glacier ice or dry permafrost in this region. We interpret these results as an indication that liquid, with sufficiently high solute content, exists at temperatures well below freezing and considered within the range suitable for microbial life. These inferred brines are widespread within permafrost and extend below glaciers and lakes. One system emanates from below Taylor Glacier into Lake Bonney and a second system connects the ocean with the eastern 18 km of the valley. A connection between these two basins was not detected to the depth limitation of the AEM survey (~350 m).1 aMikucki, Jill, A.1 aAuken, E.1 aTulaczyk, S1 aVirginia, Ross, A.1 aSchamper, C.1 aSørensen, K., I.1 aDoran, Peter, T.1 aDugan, Hilary, A.1 aFoley, N. uhttp://www.nature.com/doifinder/10.1038/ncomms783100801nas a2200253 4500008004100000022001400041245008400055210006900139260001200208300000800220490000700228100003400235700002400269700002200293700002600315700002500341700002400366700001700390700002200407700002300429700002600452700002200478856004700500 2015 eng d a1445-522600aMitochondrial DNA analyses reveal widespread tardigrade diversity in Antarctica0 aMitochondrial DNA analyses reveal widespread tardigrade diversit c12/2015 a5780 v291 aVelasco-Castrillon, Alejandro1 aMcInnes, Sandra, J.1 aSchultz, Mark, B.1 aArroniz-Crespo, Maria1 aD'Haese, Cyrille, A.1 aGibson, John, A. E.1 aAdams, Byron1 aPage, Timothy, J.1 aAustin, Andrew, D.1 aCooper, Steven, J. B.1 aStevens, Mark, I. uhttp://www.publish.csiro.au/?paper=IS1401904908nas a2200193 4500008004100000022001300041245008800054210006900142260001600211300001200227490000700239520413400246100002304380700002204403700002004425700001804445700002104463856023004484 2015 eng d a0883292700aReconstructing the evolution of Lake Bonney, Antarctica using dissolved noble gases0 aReconstructing the evolution of Lake Bonney Antarctica using dis cJan-07-2015 a46 - 610 v583 a

Lake Bonney (LB), located in Taylor valley, Antarctica, is a perennially ice-covered lake with two lobes, West Lake Bonney (WLB) and East Lake Bonney (ELB), which are separated by a narrow ridge. Numerous studies have attempted to reconstruct the evolution of LB because of its sensitivity to climatic variations and the lack of reliable millennial-scale continental records of climate in this region of Antarctica. However, these studies are limited by the availability of accurate lacustrine chronologies. Here, we attempt to better constrain the chronology of LB and thus, the evolution of past regional climate by estimating water residence times based on He, Ne and Ar concentrations and isotopic ratios in both WLB and ELB.

3He and 4He excesses up to two and three orders of magnitude and 35–150 times the atmospheric values are observed for WLB and ELB samples, respectively. In comparison, while measured 40Ar/36Ar ratios are atmospheric (∼295.5) in ELB, WLB samples display 40Ar/36Ar ratios of up to ∼315 reflecting addition of radiogenic 40Ar. Both4He and 40Ar excesses clearly identify the addition of subglacial discharge (SGD) from underneath Taylor Glacier into WLB at depths of 25 m and 35 m. He isotopic ratios suggest that He excesses are predominantly crustal (>93%) in origin with small mantle contributions (<7%). These crustal 4He and 40Ar excesses are used together with basement rock production rates of these isotopes to derive first-order approximations of water residence times for both lobes. Numerous factors capable of affecting water residence times are evaluated and corrected 4He and 40Ar water ages are used to place further constrains into the reconstruction of both WLB and ELB history. Combined 4He and 40Ar ages in WLB suggest maximum water residence times of ∼250 kyrs BP. These results support the presence of remnant water from proglacial lakes that existed during Marine Isotope Stage 7 (160–240 kyrs) in WLB, in agreement with previous studies. In comparison, 4He ages in ELB are much younger (<27 kyrs BP) and display a complex evolutionary history that is very different from WLB. 4He ages also suggest that the ELB ice cover formed significantly earlier (∼1.5 kyrs BP) than previously reported. The timing of these hydrologic changes in ELB appears to correspond to regional and global climatic events that are recorded in both the Taylor Dome ice-core record as well as in other Dry Valley Lakes.

1 aWarrier, Rohit, B.1 aCastro, Clara, M.1 aHall, Chris, M.1 aKenig, Fabien1 aDoran, Peter, T. uhttp://linkinghub.elsevier.com/retrieve/pii/S088329271500044Xhttp://api.elsevier.com/content/article/PII:S088329271500044X?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:S088329271500044X?httpAccept=text/plain04591nas a2201033 4500008004100000022001400041245009100055210006900146260001600215300001100231490000700242520199300249100002002242700002202262700001802284700001602302700002002318700001502338700001802353700001502371700001802386700001702404700001602421700001402437700001402451700001702465700001802482700002102500700001602521700001102537700001502548700002002563700001902583700001602602700001802618700001602636700001402652700001602666700001502682700001602697700001602713700001602729700001802745700001602763700001602779700001302795700001802808700001202826700001402838700001402852700001402866700001602880700001402896700001402910700002002924700001102944700001702955700001502972700002502987700001603012700001703028700001703045700001503062700001703077700001403094700001403108700001703122700001803139700001603157700002403173700002303197700001603220700001503236700001603251700001803267700001803285700001803303700001803321700001503339700001803354700002003372700001603392700001503408700001803423700001703441700001303458700002103471856006503492 2015 eng d a0954-102000aA roadmap for Antarctic and Southern Ocean science for the next two decades and beyond0 aroadmap for Antarctic and Southern Ocean science for the next tw cJan-02-2015 a3 - 180 v273 a

Antarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic community came together to ‘scan the horizon’ to identify the highest priority scientific questions that researchers should aspire to answer in the next two decades and beyond. Wide consultation was a fundamental principle for the development of a collective, international view of the most important future directions in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientific questions through structured debate, discussion, revision and voting. Questions were clustered into seven topics: i) Antarctic atmosphere and global connections, ii) Southern Ocean and sea ice in a warming world, iii) ice sheet and sea level, iv) the dynamic Earth, v) life on the precipice, vi) near-Earth space and beyond, and vii) human presence in Antarctica. Answering the questions identified by the horizon scan will require innovative experimental designs, novel applications of technology, invention of next-generation field and laboratory approaches, and expanded observing systems and networks. Unbiased, non-contaminating procedures will be required to retrieve the requisite air, biota, sediment, rock, ice and water samples. Sustained year-round access to Antarctica and the Southern Ocean will be essential to increase winter-time measurements. Improved models are needed that represent Antarctica and the Southern Ocean in the Earth System, and provide predictions at spatial and temporal resolutions useful for decision making. A co-ordinated portfolio of cross-disciplinary science, based on new models of international collaboration, will be essential as no scientist, programme or nation can realize these aspirations alone

1 aKennicutt, M.C.1 aChown, Steven, L.1 aCassano, J.J.1 aLiggett, D.1 aPeck, Lloyd, S.1 aMassom, R.1 aRintoul, S.R.1 aStorey, J.1 aVaughan, D.G.1 aWilson, T.J.1 aAllison, I.1 aAyton, J.1 aBadhe, R.1 aBaeseman, J.1 aBarrett, P.J.1 aBell, Elanor, R.1 aBertler, N.1 aBo, S.1 aBrandt, A.1 aBromwich, David1 aCary, Craig, S1 aClark, M.S.1 aConvey, Peter1 aCosta, E.S.1 aCowan, D.1 aDeconto, R.1 aDunbar, R.1 aElfring, C.1 aEscutia, C.1 aFrancis, J.1 aFricker, H.A.1 aFukuchi, M.1 aGilbert, N.1 aGutt, J.1 aHavermans, C.1 aHik, D.1 aHosie, G.1 aJones, C.1 aKim, Y.D.1 aLe Maho, Y.1 aLee, S.H.1 aLeppe, M.1 aLeitchenkov, G.1 aLi, X.1 aLipenkov, V.1 aLochte, K.1 aLópez-Martínez, J.1 aüdecke, C.1 aLyons, Berry1 aMarenssi, S.1 aMiller, H.1 aMorozova, P.1 aNaish, T.1 aNayak, S.1 aRavindra, R.1 aRetamales, J.1 aRicci, C.A.1 aRogan-Finnemore, M.1 aRopert-Coudert, Y.1 aSamah, A.A.1 aSanson, L.1 aScambos, T.1 aSchloss, I.R.1 aShiraishi, K.1 aSiegert, M.J.1 aSimões, J.C.1 aStorey, B.1 aSparrow, M.D.1 aWall, Diana, H.1 aWalsh, J.C.1 aWilson, G.1 aWinther, J.G.1 aXavier, J.C.1 aYang, H.1 aSutherland, W.J. uhttp://www.journals.cambridge.org/abstract_S095410201400067402038nas a2200181 4500008004100000022001400041245011000055210006900165260001200234300000900246490001400255520146300269100001801732700001501750700002201765700002101787856004801808 2015 eng d a1365-207900aSediment transport dynamics on an ice-covered lake: The “floating” boulders of Lake Hoare, Antarctica0 aSediment transport dynamics on an icecovered lake The floating b c04/2015 a1-120 vfirstview3 a

Between 1995 and 2011 a global positioning system survey of 13 boulders and three ablation stakes (long stakes frozen in the ice) on the frozen surface of Lake Hoare was undertaken. Data interpretation illustrates complexities of post-depositional transport dynamics of boulders. Earlier studies on comparable datasets have suggested linear ‘conveyor’ type transport mechanisms for lake surface boulders. Yet explanations for non-linear boulder displacements or ‘walks’ and the mechanisms responsible for movements are inadequate. Two modes of boulder specific movement were observed. First, localized changes in the ice surface promote individual boulder movement (rolling). Second, ice rafting, which indicates the displacement of ‘plates’ of lake ice on which the boulder is located. Ablation stakes used as fixed survey control points support the hypothesis that ice cover moves as discrete plates rather than as a single homogenous mass. Factors that create the conditions to generate either of the two modes of movement may be related to location specific energy budgets. A relationship between average orientations and prevailing wind direction was also observed. The investigation describes the local-scale behaviour of surveyed boulders, and offers methodologies and interpretive frameworks for additional studies of modern and ancient sediment transportation dynamics in Antarctic lacustrine environments.

1 aAllen, P., P.1 aHewitt, R.1 aObryk, Maciek, K.1 aDoran, Peter, T. uhttp://dx.doi.org/10.1017/S095410201400055802177nas a2200217 4500008004100000022001300041245014200054210006900196260001600265300001100281490000700292520131900299100002201618700002201640700002401662700002101686700002101707700003301728700002101761856017701782 2014 eng d a0025332400aAutonomous Year-Round Sampling and Sensing to Explore the Physical and Biological Habitability of Permanently Ice-Covered Antarctic Lakes0 aAutonomous YearRound Sampling and Sensing to Explore the Physica cJan-09-2014 a8 - 170 v483 a

The lakes of the McMurdo Dry Valleys, Antarctica, are some of the only systems on our planet that are perennially ice-covered and support year-round metabolism. As such, these ecosystems can provide important information on conditions and life in polar regions on Earth and on other icy worlds in our solar system. Working in these extreme environments of the Dry Valleys poses many challenges, particularly with respect to data collection during dark winter months when logistical constraints make fieldwork difficult. In this paper, we describe the motivation, design, and challenges for this recently deployed instrumentation in Lake Bonney, a lake that has been the subject of summer research efforts for more than 40 years. The instrumentation deployed includes autonomous water, phytoplankton, and sediment samplers as well as cable-mounted profiling platforms with dissolved gas and fluorometry sensors. Data obtained from these instruments will allow us, for the first time, to define the habitability of this environment during the polar night. We include lessons learned during deployment and recommendations for effective instrument operation in these extreme conditions.

1 aWinslow, Luke, A.1 aDugan, Hilary, A.1 aBuelow, Heather, N.1 aCronin, Kyle, D.1 aPriscu, John, C.1 aTakacs-Vesbach, Cristina, D.1 aDoran, Peter, T. uhttp://openurl.ingenta.com/content/xref?genre=article&issn=0025-3324&volume=48&issue=5&spage=8http://www.ingentaconnect.com/content/mts/mtsj/2014/00000048/00000005/art0000204850nas a2200217 4500008004100000022001300041245007600054210006900130260001200199300001400211490000800225520403500233100001704268700001704285700002204302700001904324700001404343700002404357700002104381856023004402 2014 eng d a0009254100aBoron isotopic geochemistry of the McMurdo Dry Valley lakes, Antarctica0 aBoron isotopic geochemistry of the McMurdo Dry Valley lakes Anta c10/2014 a152 - 1640 v3863 a

 

The geochemistry of boron was investigated in the ice-covered lakes and glacier meltwater streams within Taylor and Wright Valley of the McMurdo Dry Valleys (MCM), Antarctica, in order to achieve a greater understanding of the source of boron to these aquatic systems and how in-lake processes control boron concentration. Selected lake depths (surface and bottom water) and streams were analyzed for boron geochemistry. Boron stable isotope values in these waters span the range of + 12.3‰ to + 51.4‰, which corresponds to the variations from glacier meltwater streams to the hypolimnion of a highly evaporated hypersaline lake. The data demonstrate that the major sources of B to the aquatic system are via terrestrial chemical weathering of aluminosilicates within the stream channels, and a marine source, either currently being introduced by marine-derived aerosols or in the form of ancient seawater. Lakes Fryxell, Hoare, and upper waters of Lake Joyce, which experience more terrestrial influence of aluminosilicate chemical weathering via glacial meltwater streams, display a mixture of these two major sources, while the source of B in the bottom waters of Lake Joyce appears to be primarily of marine origin. Lakes Bonney and Vanda and the Blood Falls brine have a marine-like source whose δ11B values have become more positive by mineral precipitation and/or adsorption. Don Juan Pond displays a terrestrial aluminosilicate influence of a marine-like source. These hypersaline lake waters from Antarctica are similar in δ11B to other hypersaline lake waters globally, suggesting that similar processes control their B geochemistry.

 

 

1 aLeslie, D.L.1 aLyons, Berry1 aWarner, Nathaniel1 aVengosh, Avner1 aOlesik, J1 aWelch, Kathleen, A.1 aDeuerling, Kelly uhttp://linkinghub.elsevier.com/retrieve/pii/S000925411400391Xhttp://api.elsevier.com/content/article/PII:S000925411400391X?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:S000925411400391X?httpAccept=text/plain02515nas a2200169 4500008004100000022001400041245016900055210006900224260001600293300001400309490000700323520188900330100002102219700002302240700001702263856006502280 2014 eng d a0954-102000aThe effects of high meltwater on the limnology of Lake Fryxell and Lake Hoare, Taylor Valley, Antarctica, as shown by dissolved gas, tritium and chlorofluorocarbons0 aeffects of high meltwater on the limnology of Lake Fryxell and L cJan-08-2014 a331 - 3400 v263 a

Small changes in the availability of liquid water can have profound effects on the water levels, aqueous chemistry and biogeochemical dynamics of the closed-basin, perennially ice-covered lakes of the McMurdo Dry Valleys, Antarctica. We have compiled the published and unpublished data on dissolved gas, tritium and chlorofluorocarbons (CFCs) for Lake Fryxell and Lake Hoare to determine the effects of a high meltwater year (2001–02 summer) on the lakes. The dissolved gas, tritium and CFC data indicate that the pulse of freshwater that flowed onto the surfaces of the lakes did not mix extensively with the upper water column. At the bottom of Lake Hoare, the measurable CFC and lower dissolved gas values suggest that the recent meltwater may have mixed with bottom waters. The probable mechanism for this transportation is weak density currents with c. 0.1–1.5% surface water being transported downwards in Lake Hoare. This deep water input, while not constant, may have a significant effect on the chemistry of the bottom waters in Lake Hoare over time. In Lake Fryxell, the tritium and CFC data indicate that the recent meltwater did not significantly affect the bottom water chemistry; therefore, weak density currents may not be present in Lake Fryxell.

1 aDowling, Carolyn1 aPoreda, Robert, J.1 aLyons, Berry uhttp://www.journals.cambridge.org/abstract_S095410201300062X03186nas a2200181 4500008004100000245010400041210006900145260003900214490001000253520255800263653002002821653001602841653002202857653001202879100002102891700002902912856006302941 2014 eng d00aEnvironmental impacts on RubisCO from green algal laboratory isolates to Antarctic lake communities0 aEnvironmental impacts on RubisCO from green algal laboratory iso aOxford, OHbMiami Universityc20140 vPh.D.3 a

Ribulose-1,5-bisphosphate carboxylase oxygenase (RubisCO) is found in a variety of autotrophic microorganisms ranging from green algae, cyanobacteria, and chemoautotrophic bacteria. As this enzyme has the potential to catalyze carboxylation (carbon fixation) or oxygenation (photorespiration) reactions, it is regulated in response to environmental variables at the levels of transcription, translation, and post-translation by the enzyme, RubisCO activase. A combination of laboratory experiments on green algal isolates and field experiments were utilized to gain insight on carbon fixation in permanently ice-covered Antarctic lakes. RubisCO was investigated as a potential target for cold adaptation of carbon fixation in the psychrophilic green alga, Chlamydomonas raudensis UWO241 (UWO241), isolated from Lake Bonney, Antarctica. RubisCO activity, stability, and whole cell carbon fixation were measured for the psychrophile and compared to a closely related mesophilic alga, C. raudensis SAG49.72 (SAG49.72). The effect of environmental factors including light and temperature on UWO241 and SAG49.72 RubisCO activation state, an indirect measurement of RubisCO activase activity, and abundance was investigated using a modified RubisCO carboxylase assay and immunoblotting, respectively. Lastly, maximum potential RubisCO carboxylase activity was determined using a modified activity assay in multiple ice covered Antarctic lakes including Lake Bonney. This data was complemented with lake depth profiles of enzyme abundance determined by quantitative real-time PCR and RubisCO-harboring organism diversity. While purified RubisCO of the psychrophilic green alga did not function optimally at low temperature, whole cell carbon fixation was greater under such conditions, suggesting that the overall process of carbon fixation is modified to function in UWO241. Increased RubisCO abundance at low temperature may contribute to this phenomenon. Low light levels may be important in regulation of RubisCO via RubisCO activase and should be further investigated. Based on community level RubsiCO activity and enzyme abundance, light and RubisCO harboring organisms including eukaryotic algae and cyanobacteria were positively correlated, but this was variable between lakes. Dark carbon fixation was potentially important in lakes west lobe Bonney and Fryxell and this community was negatively correlated with light. Results of targeted physiology and community level experiments led to development of a carbon fixation model for Lake Bonney.

10acarbon fixation10agreen algae10aice-covered lakes10aRubisCO1 aDolhi, Jenna, M.1 aMorgan-Kiss, Rachael, M. uhttp://rave.ohiolink.edu/etdc/view?acc_num=miami140705678302341nas a2200157 4500008004100000245017500041210006900216260001200285300001200297490000700309520168800316100001502004700001402019700002102033856012902054 2014 eng d00aEstimating photosynthetic activity in microbial mats in an ice-covered Antarctic lake using automated oxygen microelectode profiling and variable chlorophyll fluorescence0 aEstimating photosynthetic activity in microbial mats in an iceco c08/2014 a674-6880 v593 a An automated oxygen microprofiler measured a positive flux of oxygen from microbial mats in ice-covered Lake Hoare, Antarctica, from noon, at a photon flux of 20 µmol m−2 s−1, through to midnight (< 2 µmol photons m−2 s−1). Daily average oxygen flux was 200 µmol m−2 h−1; and, whereas it was maximal at noon, when a 10 mm broad concentration peak was observed 5 mm below the mat surface, flux correlated only weakly with irradiance. In contrast, relative electron transfer rate, estimated from variable chlorophyll fluorescence, suggested a linear relationship between photosystem activity and irradiance. This contradiction arose because of the conjunction of photosynthetic production of oxygen deep into these transparent, gelatinous mats (diel oxygen change was observed to 17 mm depth) and oxygen diffusion rates too slow to allow equilibration of oxygen concentration profiles with instantaneous production and consumption of oxygen. To confirm this, we developed a mathematical simulation of oxygen dynamics that included diffusion, photosynthesis, and respiration. The simulation further indicated that (1) net oxygen evolution is light limited is and confined to the upper few millimeters of the mat, (2) below 5–7 mm, respiration balanced photosynthesis, (3) below 17 mm, respiration and photosynthesis approached zero, even though organic carbon and dissolved oxygen were present, and (4) photosynthesis deep into the mat was dependent on high light transmission through the gelatinous matrix. These conclusions are consistent with current understanding of mat growth dynamics and point to approaches for long-term analysis of microbial mat productivity.1 aHawes, Ian1 aGiles, H.1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/estimating-photosynthetic-activity-microbial-mats-ice-covered-antarctic-lake-using-automated02215nas a2200205 4500008004100000245009200041210006900133260004000202490001000242520158200252653001501834653001001849653001301859653002401872653001601896653001601912100002201928700002101950856003801971 2014 eng d00aGeophysics, Water Balance, and History of Thick Perennial Ice Covers on Antarctic Lakes0 aGeophysics Water Balance and History of Thick Perennial Ice Cove aChicago, ILbUniversity of Illinois0 vPh.D.3 a

Antarctic lakes are studied as sentinels of future change, for paleolimnological records contained in the sediments, and as habitats for the simple food webs that can exist in inhospitable environments. Understanding how lakes are formed and are sustained in response to landscape and climate conditions is critical in addressing the aforementioned research themes. This thesis is governed by the overarching hypothesis that an understanding of hydrologic and sediment transport processes associated with lake ice formation and preservation can be used to reveal past climatic changes, and further our awareness of current changes in climate and water balance in the McMurdo Dry Valleys of Antarctica. The first chapter focuses on water loss from closed basin lakes in Taylor Valley, Antarctica, and presents updated estimates of sublimation and ablation rates from long-term empirical measurements. The second and third chapters address the formation of Lake Vida, Antarctica. The former investigates the accretion of a 27 m ice cover, and considers the origin of thick sediment layers in the ice cover, and the latter uses two geophysical methods to quantify the extent and volume of the brine network in the subsurface beneath the lake. The results presented herein advance the study of hydrogeology in continuous permafrost, provide additional evidence for fluctuating climate states in the McMurdo Dry Valleys throughout the mid to late Holocene, and provide a case study for the preservation of water in a cold, desert environment analogous to neighboring planets.

10aAntarctica10abrine10alake ice10aMcMurdo Dry Valleys10apolar lakes10asublimation1 aDugan, Hilary, A.1 aDoran, Peter, T. uhttp://hdl.handle.net/10027/1940702874nas a2200133 4500008004100000245008500041210006900126260004000195490001000235520241400245100002202659700002102681856003802702 2014 eng d00aHydrological and Biogeochemical Modeling of Taylor Valley Lakes, East Antarctica0 aHydrological and Biogeochemical Modeling of Taylor Valley Lakes  aChicago, ILbUniversity of Illinois0 vPh.D.3 a

Taylor Valley, McMurdo Dry Valleys, East Antarctica contains three perennially ice-covered lakes located in closed basins. The lakes respond to climatic changes on seasonal and decadal scales due to their existence on a very narrow climatic spectrum. The climate has to be sufficiently warm during the austral summer to induce glacial melt yet cold enough to maintain the ice covers year round. This thesis is focused on better understanding and constraining the sensitivity of past and present lakes to changes in climatic forcings. Melt water generation for large proglacial lakes, that existed during the Last Glacial Maximum, is attributed to strong westerly winds that increase surface air temperature above freezing, prolonging the melt season. The high frequency of westerly winds during the Last Glacial Maximum, based on the ice core record from Taylor Dome, is responsible for generation of enough glacial melt to sustain large proglacial lakes during this time period, suggesting that summer surface air temperatures were as warm as present day. Contemporary lakes are much smaller, however, the effect of strong westerly winds on modern lakes is equally profound. Strong winds are responsible for aeolian sediment deposition on the surface of the ice covers. The deposited sediment, on the other hand, absorbs more solar radiation and preferentially decreases the ice thickness around it. The localized ice thinning allows a greater amount of light penetration into the water column, which is negatively correlated with chlorophyll-a concentration. This negative correlation does not indicate changes in biomass; rather, it is a result of the short-term photo-adaptation of phytoplankton to the light intensity by increasing/decreasing light harvesting antenna size. The ice thicknesses in Taylor Valley lakes have been fluctuating since the first measurements were obtained. A one-dimensional physics-based ice thickness model was developed capable of reproducing 16 years of ice thickness trends for two different lakes. The model is based on surface radiative fluxes while considering heat fluxes from the water column. Deep lakes with well-developed temperature maximum can facilitate or hinder ice thickness growth/decay due to the heat flux from the underlying water column. This finding suggests that not all perennially ice-covered lakes can be used as a proxy for climatic changes.

1 aObryk, Maciek, K.1 aDoran, Peter, T. uhttp://hdl.handle.net/10027/1890903712nas a2200157 4500008004100000245021300041210006900254260001200323300001600335490000800351520308500359100002203444700002103466700002103487856004603508 2014 eng d00aThe permanent ice cover of Lake Bonney, Antarctica: The influence of thickness and sediment distribution on photosynthetically available radiation and chlorophyll-a distribution in the underlying water column0 apermanent ice cover of Lake Bonney Antarctica The influence of t c09/2014 a1879 - 18910 v1193 a

The thick permanent ice cover on the lakes of the McMurdo Dry Valleys, Antarctica, inhibits spatial lake sampling due to logistical constraints of penetrating the ice cover. To date most sampling of these lakes has been made at only a few sites with the assumption that there is a spatial homogeneity of the physical and biogeochemical properties of the ice cover and the water column at any given depth. To test this underlying assumption, an autonomous underwater vehicle (AUV) was deployed in Lake Bonney, Taylor Valley. Measurements were obtained over the course of 2 years in a 100 × 100 m horizontal sampling grid (at a 0.2 m vertical resolution). Additionally, the AUV measured the ice thickness (in water equivalent) and collected images looking up through the ice, which were used to quantify sediment distribution on the surface and within the ice. Satellite imagery was used to map sediment distribution on the surface of the ice. We present results of the spatial investigation of the sediment distribution on the ice cover and its effects on biological processes, with particular emphasis on photosynthetically active radiation (PAR). The surface sediment is a secondary controller of the ice cover thickness, which in turn controls the depth-integrated PAR in the water column. Our data revealed that depth-integrated PAR was negatively correlated with depth-integrated chlorophyll-a (r = 0.88, p < 0.001, n = 83), which appears to be related to short-term photoadaptation of phytoplanktonic communities to spatial and temporal variation in PAR within the water column.

1 aObryk, Maciek, K.1 aDoran, Peter, T.1 aPriscu, John, C. uhttp://doi.wiley.com/10.1002/2014JG00267200623nas a2200169 4500008004100000245009600041210006900137260001200206300001200218490000700230100002100237700001800258700002100276700002200297700001700319856011700336 2014 eng d00aRadiocarbon abundance and reservoir effects in lakes of the McMurdo Dry Valleys, Antarctica0 aRadiocarbon abundance and reservoir effects in lakes of the McMu c05/2014 a811-8260 v591 aDoran, Peter, T.1 aKenig, Fabien1 aKnoepfle, Lawson1 aMikucki, Jill, A.1 aLyons, Berry uhttps://mcm.lternet.edu/content/radiocarbon-abundance-and-reservoir-effects-lakes-mcmurdo-dry-valleys-antarctica03560nas a2200397 4500008004100000022001400041245005200055210004800107260001200155300001400167490000700181520243500188100001802623700002202641700001902663700002502682700001902707700002002726700002202746700002102768700002402789700002102813700002302834700002702857700002302884700002802907700001702935700001902952700002202971700002002993700002103013700002503034700002603059700002003085856005703105 2014 eng d a0012-961500aThe spatial structure of Antarctic biodiversity0 aspatial structure of Antarctic biodiversity c05/2014 a203 - 2440 v843 a

Patterns of environmental spatial structure lie at the heart of the most fundamental and familiar patterns of diversity on Earth. Antarctica contains some of the strongest environmental gradients on the planet and therefore provides an ideal study ground to test hypotheses on the relevance of environmental variability for biodiversity. To answer the pivotal question, “How does spatial variation in physical and biological environmental properties across the Antarctic drive biodiversity?” we have synthesized current knowledge on environmental variability across terrestrial, freshwater, and marine Antarctic biomes and related this to the observed biotic patterns. The most important physical driver of Antarctic terrestrial communities is the availability of liquid water, itself driven by solar irradiance intensity. Patterns of biota distribution are further strongly influenced by the historical development of any given location or region, and by geographical barriers. In freshwater ecosystems, free water is also crucial, with further important influences from salinity, nutrient availability, oxygenation, and characteristics of ice cover and extent. In the marine biome there does not appear to be one major driving force, with the exception of the oceanographic boundary of the Polar Front. At smaller spatial scales, ice cover, ice scour, and salinity gradients are clearly important determinants of diversity at habitat and community level. Stochastic and extreme events remain an important driving force in all environments, particularly in the context of local extinction and colonization or recolonization, as well as that of temporal environmental variability. Our synthesis demonstrates that the Antarctic continent and surrounding oceans provide an ideal study ground to develop new biogeographical models, including life history and physiological traits, and to address questions regarding biological responses to environmental variability and change.

 

1 aConvey, Peter1 aChown, Steven, L.1 aClarke, Andrew1 aBarnes, David, K. A.1 aBokhorst, Stef1 aCummings, Vonda1 aDucklow, Hugh, W.1 aFrati, Francesco1 aGreen, T., G. Allan1 aGordon, Shulamit1 aGriffiths, Huw, J.1 aHoward-Williams, Clive1 aHuiskes, Ad, H. L.1 aLaybourn-Parry, Johanna1 aLyons, Berry1 aMcMinn, Andrew1 aMorley, Simon, A.1 aPeck, Lloyd, S.1 aQuesada, Antonio1 aRobinson, Sharon, A.1 aSchiaparelli, Stefano1 aWall, Diana, H. uhttp://www.esajournals.org/doi/abs/10.1890/12-2216.100634nas a2200181 4500008004100000245007700041210006900118260001200187490000600199100002100205700002400226700002300250700002000273700001900293700002400312700002000336856009600356 2013 eng d00aAccelerated thermokarst formation in the McMurdo Dry Valleys, Antarctica0 aAccelerated thermokarst formation in the McMurdo Dry Valleys Ant c07/20130 v31 aLevy, Joseph, S.1 aFountain, Andrew, G1 aDickson, James, L.1 aHead, James, W.1 aOkal, Marianne1 aMarchant, David, R.1 aWatters, Jaclyn uhttp://www.nature.com/srep/2013/130724/srep02269/full/srep02269.html?WT.ec_id=SREP-2013073002237nas a2200337 4500008004100000024003300041245010300074210006900177260001200246300001300258490000700271520126700278100001301545700001701558700001901575700001401594700002001608700001801628700001801646700001301664700001701677700001401694700002001708700001801728700001401746700002101760700001801781700002001799700001701819856006301836 2013 eng d ahdl: 10013 / epic.42531.d00100aAntarctic Thresholds - Ecosystem Resilience and Adaptation (AnT-ERA), a new SCAR-biology programme0 aAntarctic Thresholds Ecosystem Resilience and Adaptation AnTERA  c10/2013 a147-150.0 v823 a

Stresses on Antarctic ecosystems result from environmental change, including extreme events, and from (other) human impacts. Consequently, Antarctic habitats are changing, some at a rapid pace while others are relatively stable. A cascade of responses from molecular through organismic to the community level are expected. The differences in biological complexity and evolutionary histories between both polar regions and the rest of the planet suggest that stresses on polar ecosystem function may have fundamentally different outcomes from those at lower latitudes. Polar ecosystem processes are therefore key to informing wider ecological debate about the nature of stability and potential changes across the biosphere. The main goal of AnT-ERA is to facilitate the science required to examine changes in biological processes in Antarctic and sub-Antarctic marine-, freshwater and terrestrial ecosystems. Tolerance limits, as well as thresholds, resistance and resilience to environmental change will be determined. AnT-ERA is classified into three overlapping themes, which represent three levels of biological organisation: (1) molecular and physiological performance, (2) population processes and species traits, (3) ecosystem function and services.

1 aGutt, J.1 aAdams, Byron1 aBracegirdle, T1 aCowan, D.1 aCummings, Vonda1 adi Prisco, G.1 aGradinger, R.1 aIsla, E.1 aMcIntyre, T.1 aMurphy, E1 aPeck, Lloyd, S.1 aSchloss, I.R.1 aSmith, C.1 aSuckling, C., C.1 aTakahashi, A.1 aWall, Diana, H.1 aXavier, J.C. uhttp://epic.awi.de/34238/1/Polarforschung_82-2_147-150.pdf07866nas a2200205 4500008004100000022001400041245011200055210006900167260001200236300001400248490000700262520715200269100001907421700001907440700001807459700002707477700001807504700002107522856011707543 2013 eng d a1380-616500aCarbon Sequestration and Release from Antarctic Lakes: Lake Vida and West Lake Bonney (McMurdo Dry Valleys)0 aCarbon Sequestration and Release from Antarctic Lakes Lake Vida  c03/2013 a135 - 1450 v193 a

Perennial ice covers on many Antarctic lakes have resulted in high lake inorganic carbon contents. The objective of this paper was to evaluate and compare the brine and CO2 chemistries of Lake Vida (Victoria Valley) and West Lake Bonney (Taylor Valley), two lakes of the McMurdo Dry Valleys (East Antarctica), and their potential consequences during global warming. An existing geochemical model (FREZCHEM-15) was used to convert measured molarity into molality needed for the FREZCHEM model, and this model added a new algorithm that converts measured DIC into carbonate alkalinity needed for the FREZCHEM model. While quite extensive geochemical information exists for ice-covered Taylor Valley lakes, such as West Lake Bonney, only limited information exists for the recently sampled brine of >25 m ice-thick Lake Vida. Lake Vida brine had a model-calculated pCO2 = 0.60 bars at the field pH (6.20); West Lake Bonney had a model-calculated pCO2 = 5.23 bars at the field pH (5.46). Despite the high degree of atmospheric CO2supersaturation in West Lake Bonney, it remains significantly undersaturated with the gas hydrate, CO2·6H2O, unless these gas hydrates are deep in the sediment layer or are metastable having formed under colder temperatures or greater pressures. Because of lower temperatures, Lake Vida could start forming CO2·6H2O at lower pCO2 values than West Lake Bonney; but both lakes are significantly undersaturated with the gas hydrate, CO2·6H2O. For both lakes, simulation of global warming from current subzero temperatures (−13.4 °C in Lake Vida and −4.7 °C in West Lake Bonney) to 10 °C has shown that a major loss of solution-phase carbon as CO2 gases and carbonate minerals occurred when the temperatures rose above 0 °C and perennial ice covers would disappear. How important these Antarctic CO2 sources will be for future global warming remains to be seen. But a recent paper has shown that methane increased in atmospheric concentration due to deglaciation about 10,000 years ago. So, CO2 release from ice lakes might contribute to atmospheric gases in the future.

1 aMarion, G., M.1 aMurray, A., E.1 aWagner, Bernd1 aFritsen, Christian, H.1 aKenig, Fabien1 aDoran, Peter, T. uhttp://link.springer.com/10.1007/s10498-012-9184-1http://link.springer.com/content/pdf/10.1007/s10498-012-9184-102340nas a2200241 4500008004100000245013800041210006900179260001200248300001100260490000600271520148800277100002301765700002401788700002301812700001901835700002001854700002201874700001901896700001701915700001801932700002701950856012101977 2013 eng d00aCharacterization of fulvic acid fractions of dissolved organic matter during ice-out in a hyper-eutrophic, coastal pond in Antarctica0 aCharacterization of fulvic acid fractions of dissolved organic m c12/2013 a0450150 v83 aDissolved humic material (HDOM) is ubiquitous to all natural waters and its source material influences its chemical structure, reactivity, and bioavailability. While terrestrially derived HDOM reference materials distributed by the International Humic Substances Society (IHSS) have been readily available to engineering and scientific communities, a microbially derived reference HDOM was not, despite the well-characterized differences in the chemistry and reactivity of HDOM derived from terrestrial versus microbial sources. To address this gap, we collected a microbial reference fulvic acid from Pony Lake (PLFA) for distribution through the IHSS. Pony Lake is a saline coastal pond on Ross Island, Antarctica, where the landscape is devoid of terrestrial plants. Sample collection occurred over a 17-day period in the summer season at Pony Lake. During this time, the dissolved organic carbon (DOC) concentrations increased nearly two-fold, and the fulvic acid fraction (collected using the XAD-8 method) accounted for 14.6% of the DOC. During the re-concentration and desalting procedures we isolated two other chemically distinct fulvic acid fractions: (1) PLFA-2, which was high in carbohydrates and (2) PLFA-CER, which was high in nitrogen. The chemical characteristics (elemental analysis, optical characterization with UV–vis and fluorescence spectroscopy, and 13C NMR spectroscopy) of the three fulvic acid fractions helped to explain their behavior during isolation.1 aCawley, Kaelin, M.1 aMcKnight, Diane, M.1 aMiller, Penney, L.1 aCory, Rose, M.1 aFimmen, Ryan, L1 aGuerard, Jennifer1 aDieser, Markus1 aJaros, Chris1 aChin, Yu-Ping1 aForeman, Christine, M. uhttps://mcm.lternet.edu/content/characterization-fulvic-acid-fractions-dissolved-organic-matter-during-ice-out-hyper00663nas a2200157 4500008004100000245019300041210006900234260001200303300001200315490000700327100002600334700002700360700002300387700002400410856007100434 2013 eng d00aCharacterization of IHSS Pony Lake fulvic acid dissolved organic matter by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and fluorescence spectroscopy0 aCharacterization of IHSS Pony Lake fulvic acid dissolved organic c12/2013 a19 - 280 v651 aD’Andrilli, Juliana1 aForeman, Christine, M.1 aMarshall, Alan, G.1 aMcKnight, Diane, M. uhttp://www.sciencedirect.com/science/article/pii/S014663801300216700625nas a2200145 4500008004100000245013000041210006900171260001100240490000600251100002300257700002000280700002100300700002400321856013400345 2013 eng d00aCORRIGENDUM: Don Juan Pond, Antarctica: Near-surface CaCl2-brine feeding Earth’s most saline lake and implications for Mars0 aCORRIGENDUM Don Juan Pond Antarctica Nearsurface CaCl2brine feed c3/20130 v31 aDickson, James, L.1 aHead, James, W.1 aLevy, Joseph, S.1 aMarchant, David, R. uhttps://mcm.lternet.edu/content/corrigendum-don-juan-pond-antarctica-near-surface-cacl2-brine-feeding-earth%E2%80%99s-most-saline00502nas a2200133 4500008004100000245007800041210006900119260000900188300001400197490000700211100002600218700002100244856010300265 2013 eng d00aDistribution of Siliceous-Walled Algae in Taylor Valley, Antarctica Lakes0 aDistribution of SiliceousWalled Algae in Taylor Valley Antarctic c2013 a688 - 6990 v041 aWarnock, Jonathan, P.1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/distribution-siliceous-walled-algae-taylor-valley-antarctica-lakes00577nas a2200145 4500008004100000245011500041210006900156260001200225490000600237100002300243700002000266700002100286700002400307856010000331 2013 eng d00aDon Juan Pond, Antarctica: Near-surface CaCl2-brine feeding Earth's most saline lake and implications for Mars0 aDon Juan Pond Antarctica Nearsurface CaCl2brine feeding Earths m c01/20130 v31 aDickson, James, L.1 aHead, James, W.1 aLevy, Joseph, S.1 aMarchant, David, R. uhttp://www.nature.com/srep/2013/130130/srep01166/full/srep01166.html?WT.ec_id=SREP-704-2013020100501nas a2200133 4500008004100000245007300041210006900114260001200183490000700195100002200202700002200224700002100246856010000267 2013 eng d00aLake ice ablation rates from permanently ice-covered Antarctic lakes0 aLake ice ablation rates from permanently icecovered Antarctic la c01/20130 v591 aDugan, Hilary, A.1 aObryk, Maciek, K.1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/lake-ice-ablation-rates-permanently-ice-covered-antarctic-lakes00572nas a2200145 4500008004100000245015400041210006900195260001200264300001400276490000700290100001900297700002100316700001800337856007100355 2013 eng d00aMicro-hole and multigrain quartz luminescence dating of Paleodeltas at Lake Fryxell, McMurdo Dry Valleys (Antarctica), and relevance for lake history0 aMicrohole and multigrain quartz luminescence dating of Paleodelt c12/2013 a119 - 1340 v181 aBerger, G., W.1 aDoran, Peter, T.1 aThomsen, K.J. uhttp://www.sciencedirect.com/science/article/pii/S187110141300042300803nas a2200217 4500008004100000245011600041210006900157260001200226300001400238490000700252100001900259700002700278700001700305700002000322700002400342700002800366700002300394700001800417700002400435856012600459 2013 eng d00aPhysicochemical and biological dynamics in a coastal Antarctic lake as it transitions from frozen to open water0 aPhysicochemical and biological dynamics in a coastal Antarctic l c12/2013 a663–6750 v251 aDieser, Markus1 aForeman, Christine, M.1 aJaros, Chris1 aLisle, John, T.1 aGreenwood, Mark, C.1 aLaybourn-Parry, Johanna1 aMiller, Penney, L.1 aChin, Yu-Ping1 aMcKnight, Diane, M. uhttps://mcm.lternet.edu/content/physicochemical-and-biological-dynamics-coastal-antarctic-lake-it-transitions-frozen-open00753nas a2200193 4500008004100000245014000041210006900181260001200250300000800262490000700270100002100277700002300298700001700321700002500338700002400363700002400387700002200411856012600433 2012 eng d00aAntarctic Tardigrada: a first step in understanding molecular operational taxonomic units (MOTUs) and biogeography of cryptic meiofauna0 aAntarctic Tardigrada a first step in understanding molecular ope c12/2012 a5260 v261 aCzechowski, Paul1 aSands, Chester, J.1 aAdams, Byron1 aD'Haese, Cyrille, A.1 aGibson, John, A. E.1 aMcInnes, Sandra, J.1 aStevens, Mark, I. uhttps://mcm.lternet.edu/content/antarctic-tardigrada-first-step-understanding-molecular-operational-taxonomic-units-motus02734nas a2200229 4500008004100000245012900041210006900170260001600239300001100255490000600266520197000272100002402242700002202266700001902288700001602307700002202323700002002345700001702365700002102382700002402403856007702427 2012 eng d00aAt Limits of Life: Multidisciplinary Insights Reveal Environmental Constraints on Biotic Diversity in Continental Antarctica0 aAt Limits of Life Multidisciplinary Insights Reveal Environmenta cJul-09-2013 ae445780 v73 a

Multitrophic communities that maintain the functionality of the extreme Antarctic terrestrial ecosystems, while the simplest of any natural community, are still challenging our knowledge about the limits to life on earth. In this study, we describe and interpret the linkage between the diversity of different trophic level communities to the geological morphology and soil geochemistry in the remote Transantarctic Mountains (Darwin Mountains, 80°S). We examined the distribution and diversity of biota (bacteria, cyanobacteria, lichens, algae, invertebrates) with respect to elevation, age of glacial drift sheets, and soil physicochemistry. Results showed an abiotic spatial gradient with respect to the diversity of the organisms across different trophic levels. More complex communities, in terms of trophic level diversity, were related to the weakly developed younger drifts (Hatherton and Britannia) with higher soil C/N ratio and lower total soluble salts content (thus lower conductivity). Our results indicate that an increase of ion concentration from younger to older drift regions drives a succession of complex to more simple communities, in terms of number of trophic levels and diversity within each group of organisms analysed. This study revealed that integrating diversity across multi-trophic levels of biotic communities with abiotic spatial heterogeneity and geological history is fundamental to understand environmental constraints influencing biological distribution in Antarctic soil ecosystems.

 
1 aMagalhaes, Catarina1 aStevens, Mark, I.1 aCary, Craig, S1 aBall, Becky1 aStorey, Bryan, C.1 aWall, Diana, H.1 aTürk, Roman1 aRuprecht, Ulrike1 ade Bello, Francesco uhttp://journals.plos.org/plosone/article?id=10.1371/journal.pone.004457804191nas a2200445 4500008004100000022001400041245005900055210005900114260001600173300001400189490000800203520302300211100002203234700001603256700001903272700001503291700001803306700002003324700001503344700001903359700001603378700001303394700001503407700001803422700001303440700002203453700001503475700001503490700002303505700001303528700001903541700001703560700001503577700001703592700001803609700002003627700001603647700002003663856006203683 2012 eng d a0036-807500aChallenges to the Future Conservation of the Antarctic0 aChallenges to the Future Conservation of the Antarctic cJan-07-2013 a158 - 1590 v3373 a

The Antarctic Treaty System, acknowledged as a successful model of cooperative regulation of one of the globe's largest commons (1), is under substantial pressure. Concerns have been raised about increased stress on Antarctic systems from global environmental change and growing interest in the region's resources (23). Although policy-makers may recognize these challenges, failure to respond in a timely way can have substantial negative consequences. We provide a horizon scan, a systematic means for identifying emerging trends and assisting decision-makers in identifying policies that address future challenges (23). Previous analyses of conservation threats in the Antarctic have been restricted to matters for which available evidence is compelling (4). We reconsider these concerns because they might escalate quickly, judging from recent rapid environmental change in parts of Antarctica and increasing human interest in the region (see the map). We then focus on a more distant time horizon.

1 aChown, Steven, L.1 aLee, J., E.1 aHughes, K., A.1 aBarnes, J.1 aBarrett, P.J.1 aBergstrom, D.M.1 aConvey, P.1 aCowan, Don, A.1 aCrosbie, K.1 aDyer, G.1 aFrenot, Y.1 aGrant, S., M.1 aHerr, D.1 aKennicutt, M., C.1 aLamers, M.1 aMurray, A.1 aPossingham, H., P.1 aReid, K.1 aRiddle, M., J.1 aRyan, P., G.1 aSanson, L.1 aShaw, J., D.1 aSparrow, M.D.1 aSummerhayes, C.1 aTerauds, A.1 aWall, Diana, H. uhttp://www.sciencemag.org/cgi/doi/10.1126/science.122282100624nas a2200181 4500008004100000245009000041210006900131260001200200300001400212490000700226100002400233700002300257700002600280700002800306700002300334700002200357856006300379 2012 eng d00aThe Disappearing Cryosphere: Impacts and Ecosystem Responses to Rapid Cryosphere Loss0 aDisappearing Cryosphere Impacts and Ecosystem Responses to Rapid c04/2012 a405 - 4150 v621 aFountain, Andrew, G1 aCampbell, John, L.1 aSchuur, Edward, A. G.1 aStammerjohn, Sharon, E.1 aWilliams, Mark, W.1 aDucklow, Hugh, W. uhttp://bioscience.oxfordjournals.org/content/62/4/405.full00583nas a2200169 4500008004100000245008400041210006900125260001200194300001400206490000700220100001800227700002100245700002000266700002100286700002900307856007700336 2012 eng d00aEvidence of form II RubisCO ( cbbM) in a perennially ice-covered Antarctic lake0 aEvidence of form II RubisCO cbbM in a perennially icecovered Ant c11/2012 a491 - 5000 v821 aKong, Weidong1 aDolhi, Jenna, M.1 aChiuchiolo, Amy1 aPriscu, John, C.1 aMorgan-Kiss, Rachael, M. uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1574-6941.2012.01431.x/full00619nas a2200193 4500008004100000245006400041210005800105260001100163300001100174490000700185100001700192700002400209700002900233700001700262700002400279700001600303700002100319856008500340 2012 eng d00aThe geochemistry of upland ponds, Taylor Valley, Antarctica0 ageochemistry of upland ponds Taylor Valley Antarctica c2/2012 a3 - 140 v241 aLyons, Berry1 aWelch, Kathleen, A.1 aGardner, Christopher, B.1 aJaros, Chris1 aMoorhead, Daryl, L.1 aKnoepfle, J1 aDoran, Peter, T. uhttp://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=848335101017nas a2200337 4500008004100000022001400041245007500055210006900130260001200199300001800211490000800229100001900237700001800256700002700274700002700301700002300328700002000351700001900371700002400390700002500414700001700439700001800456700002100474700002700495700002400522700001800546700001900564700001900583700002100602856005600623 2012 eng d a0027-842400aMicrobial life at -13  C in the brine of an ice-sealed Antarctic lake0 aMicrobial life at 13 C in the brine of an icesealed Antarctic la c12/2012 a20626 - 206310 v1091 aMurray, A., E.1 aKenig, Fabien1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aCawley, Kaelin, M.1 aEdwards, R., L.1 aKuhn, Emanuele1 aMcKnight, Diane, M.1 aOstrom, Nathaniel, E1 aPeng, Vivian1 aPonce, Adrian1 aPriscu, John, C.1 aSamarkin, Vladimir, A.1 aTownsend, Ashley, T1 aWagh, Protima1 aYoung, Seth, A1 aYung, Pung, To1 aDoran, Peter, T. uhttp://www.pnas.org/cgi/doi/10.1073/pnas.120860710900621nas a2200181 4500008004100000245010500041210006900146260001200215300001200227490000700239100002000246700002400266700001900290700001700309700002100326700002100347856007100368 2012 eng d00aPerchlorate and chlorate biogeochemistry in ice-covered lakes of the McMurdo Dry Valleys, Antarctica0 aPerchlorate and chlorate biogeochemistry in icecovered lakes of  c12/2012 a19 - 300 v981 aJackson, Andrew1 aDavila, Alfonso, F.1 aEstrada, Nubia1 aLyons, Berry1 aCoates, John, D.1 aPriscu, John, C. uhttp://www.sciencedirect.com/science/article/pii/S001670371200511X01724nam a2200385 4500008004100000020002200041245011900063210006900182260005100251300001400302490000900316520052100325100002500846700002200871700001900893700002500912700002700937700002000964700002300984700002101007700002101028700001801049700001901067700001901086700001901105700002201124700001401146700002001160700002101180700002101201700002001222700001901242700001901261856005801280 2012 eng d a978-3-642-33179-400aPoisson Reconstruction of Extreme Submersed Environments: The ENDURANCE Exploration of an Under-Ice Antarctic Lake0 aPoisson Reconstruction of Extreme Submersed Environments The END aBerlin, HeidelbergbSpringer Berlin Heidelberg a394 - 4030 v74313 a

We evaluate the use of Poisson reconstruction to generate a 3D bathymetric model of West Lake Bonney, Antarctica. The source sonar dataset has been collected by the ENDURANCE autonomous ve- hicle in the course of two Antarctic summer missions. The reconstruction workflow involved processing 200 million datapoints to generate a high resolution model of the lake bottom, Narrows region and underwater glacier face. A novel and flexible toolset has been developed to automate the processing of the Bonney data.

1 aFebretti, Alessandro1 aRichmond, Kristof1 aGulati, Shilpa1 aFlesher, Christopher1 aHogan, Bartholomew, P.1 aJohnson, Andrew1 aStone, William, C.1 aPriscu, John, C.1 aDoran, Peter, T.1 aBebis, George1 aBoyle, Richard1 aParvin, Bahram1 aKoracin, Darko1 aFowlkes, Charless1 aWang, Sen1 aChoi, Min-Hyung1 aMantler, Stephan1 aSchulze, Jürgen1 aAcevedo, Daniel1 aMueller, Klaus1 aPapka, Michael uhttp://www.springerlink.com/content/hg97w43588229087/00655nas a2200181 4500008004100000245012000041210006900161260001100230300001400241490000700255100002200262700002300284700002200307700002500329700002800354700003300382856005800415 2011 eng d00aBacterial Community Structure Along Moisture Gradients in the Parafluvial Sediments of Two Ephemeral Desert Streams0 aBacterial Community Structure Along Moisture Gradients in the Pa c4/2011 a543 - 5560 v611 aZeglin, Lydia, H.1 aDahm, Clifford, N.1 aBarrett, John, E.1 aGooseff, Michael, N.1 aFitpatrick, Shannon, K.1 aTakacs-Vesbach, Cristina, D. uhttp://www.springerlink.com/content/r83j53334v5n505w/00571nas a2200157 4500008004100000245011700041210006900158260001200227300001400239490000700253100002600260700002600286700002200312700002100334856005800355 2011 eng d00aA diatom record of environmental change in Fryxell Basin, Taylor Valley, Antarctica, late Pleistocene to present0 adiatom record of environmental change in Fryxell Basin Taylor Va c08/2011 a257 - 2720 v461 aKonfirst, Matthew, A.1 aSjunneskog, Charlotte1 aScherer, Reed, P.1 aDoran, Peter, T. uhttp://www.springerlink.com/content/y3483576u8220081/00566nas a2200133 4500008004100000245008000041210006900121260006700190300001200257490000800269100002100277700002500298856010900323 2011 eng d00aEnvironmental Protection and Stewardship of Subglacial Aquatic Environments0 aEnvironmental Protection and Stewardship of Subglacial Aquatic E aBaltimorebAmerican Geophysical Union, Washington, DCc03/2011 a149-1570 v1921 aDoran, Peter, T.1 aVincent, Warwick, F. uhttps://mcm.lternet.edu/content/environmental-protection-and-stewardship-subglacial-aquatic-environments00641nas a2200181 4500008004100000245011500041210006900156260001100225300001400236490000700250100001800257700002100275700002100296700001800317700001900335700002000354856008500374 2011 eng d00aThe Holocene environmental history of Lake Hoare, Taylor Valley, Antarctica, reconstructed from sediment cores0 aHolocene environmental history of Lake Hoare Taylor Valley Antar c6/2011 a307 - 3190 v231 aWagner, Bernd1 aOrtlepp, Sabrina1 aDoran, Peter, T.1 aKenig, Fabien1 aMelles, Martin1 aBurkemper, Andy uhttp://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=827537400581nas a2200169 4500008004100000245008600041210006900127260001200196300001400208490000600222100002500228700002400253700002100277700002400298700001700322856007200339 2011 eng d00aHydrological Connectivity of the Landscape of the McMurdo Dry Valleys, Antarctica0 aHydrological Connectivity of the Landscape of the McMurdo Dry Va c09/2011 a666 - 6810 v51 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aDoran, Peter, T.1 aFountain, Andrew, G1 aLyons, Berry uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1749-8198.2011.00445.x00776nas a2200229 4500008004100000245011100041210006900152260001200221300001400233490000700247100002700254700001900281700002000300700001900320700002800339700002000367700001700387700002300404700001800427700002400445856007700469 2011 eng d00aWhen a habitat freezes solid: microorganisms over-winter within the ice column of a coastal Antarctic lake0 aWhen a habitat freezes solid microorganisms overwinter within th c06/2011 a401 - 4120 v761 aForeman, Christine, M.1 aDieser, Markus1 aGreenwood, Mark1 aCory, Rose, M.1 aLaybourn-Parry, Johanna1 aLisle, John, T.1 aJaros, Chris1 aMiller, Penney, L.1 aChin, Yu-Ping1 aMcKnight, Diane, M. uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1574-6941.2011.01061.x/full05611nas a2200229 4500008004100000245006100041210006000102260004000162490000900202520491500211653002205126653001505148653000905163653002605172653001705198653002405215653002405239653001505263100002505278700001705303856006105320 2010 eng d00aAeolian sediments of the McMurdo Dry Valleys, Antarctica0 aAeolian sediments of the McMurdo Dry Valleys Antarctica aColumbus, OHbOhio State University0 vM.S.3 a

The role of dust has become a topic of increasing interest in the interface between climate and geological/ecological sciences. Dust emitted from major sources, the majority of which are desert regions in the Northern Hemisphere, is transported via suspension in global wind systems and incorporated into the biogeochemical cycles of the ecosystems where it is ultimately deposited. While emissions within the McMurdo Dry Valleys (MDV) region of Antarctica are small compared to other source regions, the redistribution of new, reactive material by wind may be important to sustaining life in the ecosystem.


The interaction of the dry, warm foehn winds and the cool, moist coastal breezes “recycles” soil particles throughout the landscape. The bulk of sediment movement occurs during foehn events in the winter that redistribute material throughout the MDV. To understand the source and transfer of this material samples were collected early in the austral summer (November 2008) prior to the initiation of extensive ice melt from glacial and lake surfaces, aeolian landforms, and elevated sediment traps. These were preserved and processed for grain size distribution and major element composition at the sand and silt particle sizes. Major elemental oxide analysis indicated that the silt and sand size particles are of different composition: SiO2 values for silt range from 50 to 59% by weight and for sand range from 59 to 74%. When compared to the elemental oxide composition four rock types present in the MDV, the composition of the silt indicates a mixing influenced mostly by the igneous rock types (Ferrar Dolerite and McMurdo Volcanic basanite) and sand a mixing influenced largely by the sedimentary rocks (Beacon Sandstone and the metasedimentary Basement Complex). This could imply a local source of the aeolian material that is corroborated by low CIA values at both particle sizes (44-57%) indicating low degrees of chemical weathering. In addition, comparison of 87Sr/86Sr and 143Nd/144Nd to values published for the major MDV rock types and ice core dust to values analyzed in 3 silt size glacier sample and one bulk glacier sample also indicates a local source of sediments and that it is not likely to be transferred inland.


During the melt season, the aeolian material is actively solubilized where it interacts with water, releasing solutes and vital bioavailable nutrients throughout the aquatic system. Differences in the chemistry of supra- and proglacial streams as well as lake surface waters may be derived from the deposition and dissolution of these aeolian sediments. To simulate these conditions, a two-step leaching method using deionized water to represent glacial melt in field conditions was employed and leachates analyzed for major ion and nutrient constituents. Leachates represent a small degree (<0.7%) of dissolution of major elements, and are solubilized to a greater extent from samples closer to the coast or with increased silt content. The composition of the leachates reflects the dissolution of the major salts found in the MDV. Leach 1 (cold water) indicates that Na- and Cl-bearing salt phases are dissolved to a greater extent than seen in Leach 2 (freeze-thaw). Conversely, Leach 2 compositions indicate that carbonate mineral dissolution and Mg-bearing silicate weathering are proceeding to a greater extent than in Leach 1.


Inorganic N:P ratios follow the same patterns of nutrient limitations based on the Redfield Ratio found by Priscu (1995) in the terminal lakes of the Taylor Valley: N-limited in the Fryxell and Hoare basins (east) and P-limited in the Bonney basin (west). This is also consistent with the age of the tills in the area, as found by Gudding (2003). The concentration of soluble Fe in the leachates is about the same as soluble inorganic P, and thus is not a limiting nutrient in the leachates. Comparison of total dissolved N and P to their inorganic counterparts reveals increased organic nutrients in the glacier and lake leachates that may indicate the influence of biota. Nutrient fluxes based on known sediment fluxes from elevated sediment traps deployed throughout the MDV and the composition of these leachates range from 0.34-330 g a-1 for N, 0.02-8.3 g a-1 for P, and 0.03-8.6 g a-1 for Fe. These are at least two orders of magnitude less than calculated loads from streams to the lakes in the Taylor Valley and, thus, should be considered underestimations or minima.


This work provides the first investigation into the composition and source of aeolian transported materials in the MDV, as well of what is potentially solubilized from it during the austral summer melt season. In addition, it will contribute to the understanding of the interplay between aeolian and aquatic processes in the MDV and further the understanding of this unique ecosystem.

10aaeolian transport10aAntarctica10adust10aexperimental leaching10ageochemistry10aMcMurdo Dry Valleys10asediment provenance10aweathering1 aDeuerling, Kelly, M.1 aLyons, Berry uhttp://rave.ohiolink.edu/etdc/view?acc_num=osu129052486200618nas a2200169 4500008004100000245011400041210006900155260001200224300001800236490000800254100002100262700002300283700002400306700002100330700002600351856007100377 2010 eng d00aAntarctic lakes suggest millennial reorganizations of Southern Hemisphere atmospheric and oceanic circulation0 aAntarctic lakes suggest millennial reorganizations of Southern H c12/2010 a21355 - 213590 v1071 aHall, Brenda, L.1 aDenton, George, H.1 aFountain, Andrew, G1 aHendy, Chris, H.1 aHenderson, Gideon, M. uhttp://www.pnas.org/content/107/50/21355.full.pdf#page=1&view=FitH00722nas a2200193 4500008004100000020001800041245008800059210006900147260004200216300001400258100002500272700002400297700001700321700001700338700002100355700001700376700002400393856011100417 2010 eng d a978052188919300aAntarctic McMurdo Dry Valley stream ecosystems as analog to fluvial systems on Mars0 aAntarctic McMurdo Dry Valley stream ecosystems as analog to fluv aCambridgebCambridge University Press a139 - 1591 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aCarr, M., H.1 aBaeseman, J.1 aDoran, Peter, T.1 aLyons, Berry1 aMcKnight, Diane, M. uhttps://mcm.lternet.edu/content/antarctic-mcmurdo-dry-valley-stream-ecosystems-analog-fluvial-systems-mars00861nas a2200253 4500008004100000245013000041210006900171260001200240300001400252490000800266100001300274700002600287700001500313700001400328700002200342700001500364700001500379700001500394700001400409700001600423700002100439700002100460856012600481 2010 eng d00aDesign and deployment of a four-degrees-of-freedom hovering autonomous underwater vehicle for sub-ice exploration and mapping0 aDesign and deployment of a fourdegreesoffreedom hovering autonom c11/2010 a341 - 3610 v2241 aStone, W1 aHogan, Bartholomew, P1 aFlesher, C1 aGulati, S1 aRichmond, Kristof1 aMurarka, A1 aKuhlman, G1 aIdharan, M1 aSiegel, V1 aPrice, R, M1 aDoran, Peter, T.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/design-and-deployment-four-degrees-freedom-hovering-autonomous-underwater-vehicle-sub-ice00571nas a2200145 4500008004100000245009100041210006900132260001500201300001200216100001700228700002400245700002100269700002400290856011100314 2010 eng d00aA dynamic physical model for soil temperature and water in Taylor Valley, Antarctica.0 adynamic physical model for soil temperature and water in Taylor  c05/13/2010 a419-4341 aHunt, H., W.1 aFountain, Andrew, G1 aDoran, Peter, T.1 aBasagic, Hassan, J. uhttps://mcm.lternet.edu/content/dynamic-physical-model-soil-temperature-and-water-taylor-valley-antarctica00672nas a2200157 4500008004100000245016900041210006900210260001200279300001400291490000700305100002700312700001200339700002400351700001700375856012200392 2010 eng d00aLatitudinal distribution and mitochondrial DNA (COI) variability of Stereotydeus spp. (Acari: Prostigmata) in Victoria Land and the central Transantarctic Mountains0 aLatitudinal distribution and mitochondrial DNA COI variability o c12/2010 a749 - 7560 v221 aDemetras, Nicholas, J.1 aHogg, I1 aBanks, Jonathan, C.1 aAdams, Byron uhttps://mcm.lternet.edu/content/latitudinal-distribution-and-mitochondrial-dna-coi-variability-stereotydeus-spp-acari00763nam a2200241 4500008004100000020001800041245005800059210005800117260004300175300000800218490000600226653002200232100002100254700001700275700002400292700002400316700002500340700003300365700002200398700002000420700001800440856006300458 2010 eng d a978051171225800aLife in Antarctic Deserts and Other Cold Environments0 aLife in Antarctic Deserts and Other Cold Environments aCambridgebCambridge University Press. a3070 v510aPlanetary Science1 aDoran, Peter, T.1 aLyons, Berry1 aMcKnight, Diane, M.1 aMcKnight, Diane, M.1 aGooseff, Michael, N.1 aTakacs-Vesbach, Cristina, D.1 aMikucki, Jill, A.1 aTranter, Martyn1 aSun, Henry, J uhttp://ebooks.cambridge.org/ebook.jsf?bid=CBO978051171225800662nas a2200181 4500008004100000245013300041210006900174260001200243300001400255490000800269100002400277700002200301700002000323700002100343700001800364700002700382856007100409 2010 eng d00aNew insights into the origin and evolution of Lake Vida, McMurdo Dry Valleys, Antarctica — A noble gas study in ice and brines0 aNew insights into the origin and evolution of Lake Vida McMurdo  c01/2010 a112 - 1220 v2891 aMalone, Jessica, L.1 aCastro, Clara, M.1 aHall, Chris, M.1 aDoran, Peter, T.1 aKenig, Fabien1 aMcKay, Christopher, P. uhttp://www.sciencedirect.com/science/article/pii/S0012821X0900633500684nas a2200169 4500008004100000245012300041210006900164260001100233300001400244490000700258100002800265700002400293700002900317700002100346700001800367856012900385 2010 eng d00aOrigin and tentative identification of tri to pentaunsaturated ketones in sediments from Lake Fryxell, East Antarctica0 aOrigin and tentative identification of tri to pentaunsaturated k c4/2010 a386 - 3970 v411 aJaraula, Caroline, M.B.1 aBrassell, Simon, C.1 aMorgan-Kiss, Rachael, M.1 aDoran, Peter, T.1 aKenig, Fabien uhttps://mcm.lternet.edu/content/origin-and-tentative-identification-tri-pentaunsaturated-ketones-sediments-lake-fryxell-east00643nas a2200169 4500008004100000245011300041210006900154260001200223300001400235490000700249100001800256700002100274700001800295700002100313700001900334856012000353 2010 eng d00aPalaeoenvironmental implications derived from a piston core from east lobe Bonney, Taylor Valley, Antarctica0 aPalaeoenvironmental implications derived from a piston core from c10/2010 a522 - 5300 v221 aWagner, Bernd1 aOrtlepp, Sabrina1 aKenig, Fabien1 aDoran, Peter, T.1 aMelles, Martin uhttps://mcm.lternet.edu/content/palaeoenvironmental-implications-derived-piston-core-east-lobe-bonney-taylor-valley00649nas a2200169 4500008004100000020001800041245010800059210006900167260004200236300001400278100002200292700001700314700001500331700002200346700002100368856009000389 2010 eng d a978052188919300aSaline lakes and ponds in the McMurdo Dry Valleys: ecological analogs to martian paleolake environments0 aSaline lakes and ponds in the McMurdo Dry Valleys ecological ana aCambridgebCambridge University Press a160 - 1941 aMikucki, Jill, A.1 aLyons, Berry1 aHawes, Ian1 aLanoil, Brian, D.1 aDoran, Peter, T. uhttp://ebooks.cambridge.org/chapter.jsf?bid=CBO9780511712258&cid=CBO9780511712258A01300598nas a2200145 4500008004100000245012800041210006900169260001200238300001400250490000600264100001900270700002100289700001800310856012400328 2010 eng d00aSingle-grain and multigrain luminescence dating of on-ice and lake-bottom deposits at Lake Hoare, Taylor Valley, Antarctica0 aSinglegrain and multigrain luminescence dating of onice and lake c12/2010 a679 - 6900 v51 aBerger, G., W.1 aDoran, Peter, T.1 aThomsen, K.J. uhttps://mcm.lternet.edu/content/single-grain-and-multigrain-luminescence-dating-ice-and-lake-bottom-deposits-lake-hoare00839nas a2200217 4500008004100000020002200041245013600063210007100199260003300270300001400303100001400317700002200331700001500353700002600368700001500394700002200409700002100431700001300452700002100465856013500486 2010 eng d a978-1-4244-5038-100aToward autonomous scientific exploration of ice-covered lakes—Field experiments with the ENDURANCE AUV in an Antarctic Dry Valley0 aToward autonomous scientific exploration of icecovered lakes—Fie aAnchorage, AKbIEEEc05/2010 a308 - 3151 aGulati, S1 aRichmond, Kristof1 aFlesher, C1 aHogan, Bartholomew, P1 aMurarka, A1 aKuhlmann, Gregory1 aSridharan, Mohan1 aStone, W1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/toward-autonomous-scientific-exploration-ice-covered-lakes%E2%80%94field-experiments-endurance-auv01928nas a2200169 4500008004100000245010300041210006900144260001200213300001400225490000700239520131500246100001901561700002001580700002101600700002701621856011001648 2010 eng d00aViable microbes in ice: application of molecular assays to McMurdo Dry Valley lake ice communities0 aViable microbes in ice application of molecular assays to McMurd c10/2010 a470 - 4760 v223 a

The permanent ice covers of the McMurdo Dry Valley lakes, Antarctica, are colonized by a diverse microbial assemblage. We collected ice cores from Lakes Fryxell, Hoare and Bonney. Propidium monoazide (PMA) was used in combination with quantitative PCR (qPCR) and denaturing gradient gel electrophoresis (DGGE) to examine membrane integrity of prokaryotes in these extreme environments. PMA selectively penetrates cells with compromised membranes and modifies their DNA resulting in the suppression of PCR amplification. Our results based on analysis of 16S rRNA genes demonstrate that despite the hostile conditions of the Dry Valleys, the permanent ice covers of the lakes support a ‘potentially viable’ microbial community. The level of membrane integrity, as well as diversity, was higher in samples where sediment was entrapped in the ice cover. Pronounced differences in the fraction of cells with intact and compromised cell membranes were found for Lake Fryxell and east lobe of Lake Bonney, both expressed in differences in DGGE banding patterns and qPCR signal reductions. Limitations in the ability to distinguish between intact or compromised cells occurred in samples from Lake Hoare and west lobe of Lake Bonney due to low DNA template concentrations recovered from the samples.

1 aDieser, Markus1 aNocker, Andreas1 aPriscu, John, C.1 aForeman, Christine, M. uhttp://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=7909836&fileId=S095410201000040400627nas a2200157 4500008004100000245011700041210006900158300001400227490000700241100001500248700001800263700002100281700002100302700002400323856012200347 2009 eng d00aComposition and Biodegradation of a Synthetic Oil Spilled on the Perennial Ice Cover of Lake Fryxell, Antarctica0 aComposition and Biodegradation of a Synthetic Oil Spilled on the a2708-27130 v431 aJaraula, C1 aKenig, Fabien1 aDoran, Peter, T.1 aPriscu, John, C.1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/composition-and-biodegradation-synthetic-oil-spilled-perennial-ice-cover-lake-fryxell00419nas a2200133 4500008004100000245005700041210005700098260000900155300000700164490000700171100002100178700002600199856006000225 2009 eng d00aExamining the Scientific Consensus on Climate Change0 aExamining the Scientific Consensus on Climate Change c2009 a220 v901 aDoran, Peter, T.1 aZimmerman, Maggie, K. uhttp://www.agu.org/pubs/crossref/2009/2009EO030002.shtm01451nas a2200481 4500008004100000245006900041210006900110260001200179300001600191490001400207100002200221700002200243700002200265700002500287700002400312700002600336700001800362700001800380700002100398700002200419700002800441700001700469700001800486700002200504700002000526700002300546700002400569700002100593700001900614700002200633700001800655700002500673700001800698700002600716700002500742700002100767700002000788700002300808700002700831700002700858700002600885856005800911 2009 eng d00aLakes and reservoirs as regulators of carbon cycling and climate0 aLakes and reservoirs as regulators of carbon cycling and climate c11/2009 a2298–23140 v54 part 21 aTranvik, Lars, J.1 aDowning, John, A.1 aCotner, James, B.1 aLoiselle, Steven, A.1 aStriegl, Robert, G.1 aBallatore, Thomas, J.1 aDillon, Peter1 aFinlay, Kerri1 aFortino, Kenneth1 aKnoll, Lesley, B.1 aKortelainen, Pirkko, L.1 aKutser, Tiit1 aLarsen, Soren1 aLaurion, Isabelle1 aLeech, Dina, M.1 aMcCallister, Leigh1 aMcKnight, Diane, M.1 aMelack, John, M.1 aOverholt, Erin1 aPorter, Jason, A.1 aPrairie, Yves1 aRenwick, William, H.1 aRoland, Fabio1 aSherman, Bradford, S.1 aSchindler, David, W.1 aSobek, Sebastian1 aTremblay, Alain1 aVanni, Michael, J.1 aVerschoor, Antonie, M.1 avon Wachenfeldt, Eddie1 aWeyhenmeyer, Gesa, A. uhttp://aslo.org/lo/toc/vol_54/issue_6_part_2/2298.pdf00641nas a2200157 4500008004100000245014100041210006900182300001200251490000800263100001600271700002100287700001800308700001700326700001700343856012300360 2009 eng d00aParticulate organic and dissolved inorganic carbon stable isotopic compositions in Taylor Valley lakes, Antarctica: the effect of legacy0 aParticulate organic and dissolved inorganic carbon stable isotop a139-1560 v6321 aKnoepfle, J1 aDoran, Peter, T.1 aKenig, Fabien1 aLyons, Berry1 aGalchenko, V uhttps://mcm.lternet.edu/content/particulate-organic-and-dissolved-inorganic-carbon-stable-isotopic-compositions-taylor00514nas a2200133 4500008004100000245008400041210006900125260000900194300000800203490000700211100002100218700002600239856011500265 2009 eng d00aReply to Comments on “Examining the Scientific Consensus on Climate Change”0 aReply to Comments on Examining the Scientific Consensus on Clima c2009 a2330 v901 aDoran, Peter, T.1 aZimmerman, Maggie, K. uhttps://mcm.lternet.edu/content/reply-comments-%E2%80%9Cexamining-scientific-consensus-climate-change%E2%80%9D00639nas a2200169 4500008004100000245009800041210006900139300001200208490000600220100002100226700002700247700001900274700001800293700002700311700001200338856011900350 2008 eng d00aEntry approach into pristine ice-sealed lakes - Lake Vida, East Antarctica, a model ecosystem0 aEntry approach into pristine icesealed lakes Lake Vida East Anta a542-5470 v61 aDoran, Peter, T.1 aFritsen, Christian, H.1 aMurray, A., E.1 aKenig, Fabien1 aMcKay, Christopher, P.1 aKyne, J uhttps://mcm.lternet.edu/content/entry-approach-pristine-ice-sealed-lakes-lake-vida-east-antarctica-model-ecosystem01642nas a2200541 4500008004100000245010100041210006900142260001200211300001400223490000700237100002000244700002300264700002100287700002300308700002900331700002300360700002200383700002400405700001700429700002000446700002100466700002600487700002000513700002200533700002400555700002400579700001900603700002200622700002200644700002100666700001700687700002200704700002300726700001500749700001900764700002100783700002100804700002400825700002200849700002300871700002600894700002300920700001900943700002900962700001500991700001701006856007701023 2008 eng d00aGlobal decomposition experiment shows soil animal impacts on decomposition are climate dependent0 aGlobal decomposition experiment shows soil animal impacts on dec c11/2008 a2661-26770 v141 aWall, Diana, H.1 aBradford, Mark, A.1 aStJohn, Mark, G.1 aTrofymow, John, A.1 aBehan-Pelletier, Valerie1 aBignell, David, E.1 aDangerfield, Mark1 aParton, William, J.1 aRusek, Josef1 aVoigt, Winfried1 aWolters, Volkmar1 aGardel, Holley, Zadeh1 aAyuke, Fred, O.1 aBashford, Richard1 aBeljakova, Olga, I.1 aBohlen, Patrick, J.1 aBrauman, Alain1 aFlemming, Stephen1 aHenschel, Joh, R.1 aJohnson, Dan, L.1 aJones, Hefin1 aKovarova, Marcela1 aKranabetter, Marty1 aKutny, Les1 aLin, Kuo-Chuan1 aMaryati, Mohamed1 aMasse, Dominique1 aPokarzhevsk, Andrei1 aRahman, Homathevi1 aSabara, Millor, G.1 aSalamon, Joerg-Alfred1 aSwift, Michael, J.1 aVarela, Amanda1 aVasconcelos, Heraldo, L.1 aWhite, Don1 aZou, Xiaming uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2008.01672.x/full00775nas a2200217 4500008004100000245010100041210006900142260001500211300001200226490000700238653002100245653001200266100002100278700002700299700002400326700002200350700002400372700001700396700002200413856012200435 2008 eng d00aHydrologic response to extreme warm and cold summers in the McMurdo Dry Valleys, East Antarctica0 aHydrologic response to extreme warm and cold summers in the McMu c05/16/2008 a499-5090 v2010aClimate Response10astreams1 aDoran, Peter, T.1 aMcKay, Christopher, P.1 aFountain, Andrew, G1 aNylen, Thomas, H.1 aMcKnight, Diane, M.1 aJaros, Chris1 aBarrett, John, E. uhttps://mcm.lternet.edu/content/hydrologic-response-extreme-warm-and-cold-summers-mcmurdo-dry-valleys-east-antarctica00672nas a2200193 4500008004100000245008200041210006900123300001400192490000700206100002500213700002500238700002400263700001700287700001600304700001600320700002100336700001700357856010400374 2008 eng d00aInland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica0 aInland diatoms from the McMurdo Dry Valleys and James Ross Islan a1378-13920 v121 aEsposito, Rhea, M.M.1 aSpaulding, Sarah, A.1 aMcKnight, Diane, M.1 aDe Vijver, B1 aKopalova, K1 aLubinski, D1 aHall, Brenda, L.1 aWhittaker, T uhttps://mcm.lternet.edu/content/inland-diatoms-mcmurdo-dry-valleys-and-james-ross-island-antarctica00528nas a2200145 4500008004100000245005900041210005900100260003600159100001500195700002100210700001700231700002500248700002800273856008100301 2008 eng d00aOrigin and geomorphology of lakes in the polar regions0 aOrigin and geomorphology of lakes in the polar regions aOxfordbOxford University Press1 aPienitz, R1 aDoran, Peter, T.1 aLamoureuz, S1 aVincent, Warwick, F.1 aLaybourn-Parry, Johanna uhttps://mcm.lternet.edu/content/origin-and-geomorphology-lakes-polar-regions00556nas a2200121 4500008004100000245011000041210006900151260003600220490000900256100002600265700002100291856012200312 2008 eng d00aProvenance of organic matter in Taylor Valley, Antarctica lakes: Scanning Electron Microscopy of sediment0 aProvenance of organic matter in Taylor Valley Antarctica lakes S bUniversity of Illinois, Chicago0 vM.S.1 aWarnock, Jonathan, P.1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/provenance-organic-matter-taylor-valley-antarctica-lakes-scanning-electron-microscopy00685nas a2200205 4500008004100000245010300041210006900144260000900213490000700222100002300229700002300252700002900275700001500304700002300319700002100342700001500363700001500378700002500393856006100418 2008 eng d00aReply to comment by K. Gajewski on “Abrupt environmental change in Canada's northernmost lake”0 aReply to comment by K Gajewski on Abrupt environmental change in c20080 v351 aAntoniades, Dermot1 aCrawley, Catherine1 aDouglas, Marianne, S. V.1 aPienitz, R1 aAndersen, Dale, T.1 aDoran, Peter, T.1 aHawes, Ian1 aPollard, W1 aVincent, Warwick, F. uhttp://www.agu.org/pubs/crossref/2008/2007GL032889.shtml00645nas a2200157 4500008004100000245012900041210006900170300001200239490000800251100001500259700001800274700002100292700002100313700002400334856012900358 2008 eng d00aSPME-GCMS study of the natural attenuation of aviation diesel spilled on the perennial ice cover of Lake Fryxell, Antarctica0 aSPMEGCMS study of the natural attenuation of aviation diesel spi a250-2620 v4071 aJaraula, C1 aKenig, Fabien1 aDoran, Peter, T.1 aPriscu, John, C.1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/spme-gcms-study-natural-attenuation-aviation-diesel-spilled-perennial-ice-cover-lake-fryxell00658nas a2200181 4500008004100000245013600041210006900177300001400246490000700260100002100267700002500288700001900313700002400332700002000356700002500376700001700401856005800418 2008 eng d00aSupersaturated N2O in a perennially ice-covered Antarctic lake: Molecular and stable isotopic evidence for a biogeochemical relict.0 aSupersaturated N2O in a perennially icecovered Antarctic lake Mo a2439-24500 v531 aPriscu, John, C.1 aChristner, Brent, C.1 aDore, John, E.1 aWestley, Marian, B.1 aPopp, Brian, N.1 aCasciotti, Karen, L.1 aLyons, Berry uhttp://brent.xner.net/pdf/Priscu_etal2008_ELB-N2O.pdf03147nas a2200241 4500008004100000245006800041210006800109260001200177300001400189490000800203520239000211653001102601100002202612700002302634700001702657700002402674700002102698700002402719700002002743700002402763700002102787856009702808 2007 eng d00aBiogeochemical stoichiometry of Antarctic Dry Valley ecosystems0 aBiogeochemical stoichiometry of Antarctic Dry Valley ecosystems c02/2007 aG01010+120 v1123 a

Among aquatic and terrestrial landscapes of the McMurdo Dry Valleys, Antarctica, ecosystem stoichiometry ranges from values near the Redfield ratios for C:N:P to nutrient concentrations in proportions far above or below ratios necessary to support balanced microbial growth. This polar desert provides an opportunity to evaluate stoichiometric approaches to understand nutrient cycling in an ecosystem where biological diversity and activity are low, and controls over the movement and mass balances of nutrients operate over 10–106 years. The simple organisms (microbial and metazoan) comprising dry valley foodwebs adhere to strict biochemical requirements in the composition of their biomass, and when activated by availability of liquid water, they influence the chemical composition of their environment according to these ratios. Nitrogen and phosphorus varied significantly in terrestrial and aquatic ecosystems occurring on landscape surfaces across a wide range of exposure ages, indicating strong influences of landscape development and geochemistry on nutrient availability. Biota control the elemental ratio of stream waters, while geochemical stoichiometry (e.g., weathering, atmospheric deposition) evidently limits the distribution of soil invertebrates. We present a conceptual model describing transformations across dry valley landscapes facilitated by exchanges of liquid water and biotic processing of dissolved nutrients. We conclude that contemporary ecosystem stoichiometry of Antarctic Dry Valley soils, glaciers, streams, and lakes results from a combination of extant biological processes superimposed on a legacy of landscape processes and previous climates.

10aBiggie1 aBarrett, John, E.1 aVirginia, Ross, A.1 aLyons, Berry1 aMcKnight, Diane, M.1 aPriscu, John, C.1 aFountain, Andrew, G1 aWall, Diana, H.1 aMoorhead, Daryl, L.1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/biogeochemical-stoichiometry-antarctic-dry-valley-ecosystems00541nas a2200121 4500008004100000245010000041210006900141260003600210490000900246100002000255700002100275856012300296 2007 eng d00aLacustrine History of Lake Hoare, McMurdo Dry Valleys, Antarctica, Based on Long Sediment Cores0 aLacustrine History of Lake Hoare McMurdo Dry Valleys Antarctica  bUniversity of Illinois, Chicago0 vM.S.1 aBurkemper, Andy1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/lacustrine-history-lake-hoare-mcmurdo-dry-valleys-antarctica-based-long-sediment-cores00393nas a2200121 4500008004100000245004600041210004600087490000700133100001700140700002400157700001500181856007500196 2007 eng d00aOrganic carbon in Antarctic precipitation0 aOrganic carbon in Antarctic precipitation0 v341 aLyons, Berry1 aWelch, Kathleen, A.1 aDoggett, J uhttps://mcm.lternet.edu/content/organic-carbon-antarctic-precipitation00625nas a2200169 4500008004100000245010600041210006900147300001200216490000700228100001700235700002000252700001300272700001500285700001500300700001200315856012800327 2007 eng d00aThe southernmost worm, Scottnema lindsayae (Nematoda): diversity, dispersal and ecological stability.0 asouthernmost worm Scottnema lindsayae Nematoda diversity dispers a809-8150 v301 aAdams, Byron1 aWall, Diana, H.1 aGozel, U1 aDillman, A1 aChaston, J1 aHogg, I uhttps://mcm.lternet.edu/content/southernmost-worm-scottnema-lindsayae-nematoda-diversity-dispersal-and-ecological-stability00498nas a2200121 4500008004100000245007800041210006900119260003600188490000900224100002100233700002100254856010100275 2007 eng d00aStable Carbon Isotope Analyses of Sediments from Lake Fryxell, Antarctica0 aStable Carbon Isotope Analyses of Sediments from Lake Fryxell An bUniversity of Illinois, Chicago0 vM.S.1 aMoore-Topinka, N1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/stable-carbon-isotope-analyses-sediments-lake-fryxell-antarctica00704nas a2200169 4500008004100000245010300041210006900144260005400213100002500267700002400292700002100316700001700337700001700354700001900371700002700390856011700417 2007 eng d00aTrends in discharge and flow season timing of the Onyx River, Wright Valley, Antarctica since 19690 aTrends in discharge and flow season timing of the Onyx River Wri bU.S. Geological Survey Open-File Report 2007-10471 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aDoran, Peter, T.1 aLyons, Berry1 aCooper, Alan1 aRaymond, Carol1 aTeam, ISAES, Editorial uhttps://mcm.lternet.edu/content/trends-discharge-and-flow-season-timing-onyx-river-wright-valley-antarctica-196901738nas a2200229 4500008004100000245008300041210006900124260001200193300001100205490000700216520101800223653001101241100002501252700001201277700002401289700001101313700001301324700002501337700002101362700001601383856010901399 2006 eng d00aAntarctic Climate Cooling and Response of Diatoms in Glacial Meltwater Streams0 aAntarctic Climate Cooling and Response of Diatoms in Glacial Mel c04/2006 aL074060 v333 a

To understand biotic responses to an Antarctic cooling trend, we analyzed diatom samples from glacial meltwater streams in the McMurdo Dry Valleys, the largest ice-free area in Antarctica. Diatoms are abundant in these streams, and 24 of 40 species have only been found in the Antarctic. The percentage of these Antarctic diatom species increased with decreasing annual stream flow and increasing harshness of the stream habitat. The species diversity of assemblages reached a maximum when the Antarctic species accounted for 40–60% of relative diatom abundance. Decreased solar radiation and air-temperatures reduce annual stream flow, raising the dominance of these Antarctic species to levels above 60%. Thus, cooling favors the Antarctic species, and lowers diatom species diversity in this region.

10aBiggie1 aEsposito, Rhea, M.M.1 aHorn, S1 aMcKnight, Diane, M.1 aCox, M1 aGrant, M1 aSpaulding, Sarah, A.1 aDoran, Peter, T.1 aCozzetto, K uhttps://mcm.lternet.edu/content/antarctic-climate-cooling-and-response-diatoms-glacial-meltwater-streams00655nas a2200181 4500008004100000245011400041210006900155300000800224490000800232100001400240700001400254700002100268700001800289700001400307700001400321700001300335856012500348 2006 eng d00aGlacial and postglacial sedimentation in the Fryxell basin, Taylor Valley, Southern Victoria Land, Antarctica0 aGlacial and postglacial sedimentation in the Fryxell basin Taylo a3200 v3411 aWagner, B1 aMelles, M1 aDoran, Peter, T.1 aKenig, Fabien1 aForman, S1 aPierau, R1 aAllan, P uhttps://mcm.lternet.edu/content/glacial-and-postglacial-sedimentation-fryxell-basin-taylor-valley-southern-victoria-land00551nas a2200145 4500008004100000245008500041210006900126300000800195490000700203100002400210700002200234700001600256700002000272856011300292 2006 eng d00aGlacier mass balances (1993-2001) Taylor Valley, McMurdo Dry Valleys, Antarctica0 aGlacier mass balances 19932001 Taylor Valley McMurdo Dry Valleys a4510 v521 aFountain, Andrew, G1 aNylen, Thomas, H.1 aMacClune, K1 aDana, Gayle, L. uhttps://mcm.lternet.edu/content/glacier-mass-balances-1993-2001-taylor-valley-mcmurdo-dry-valleys-antarctica00687nas a2200181 4500008004100000245010500041210006900146260001200215300001000227490000700237100002500244700001700269700002400286700002200310700002400332700002100356856012800377 2006 eng d00aA stable isotopic investigation of a polar desert hydrologic system, McMurdo Dry Valleys, Antarctica0 astable isotopic investigation of a polar desert hydrologic syste c02/2006 a60-710 v381 aGooseff, Michael, N.1 aLyons, Berry1 aMcKnight, Diane, M.1 aVaughn, Bruce, H.1 aFountain, Andrew, G1 aDowling, Carolyn uhttps://mcm.lternet.edu/content/stable-isotopic-investigation-polar-desert-hydrologic-system-mcmurdo-dry-valleys-antarctica00559nas a2200157 4500008004100000245008000041210006900121490000700190100001300197700001400210700001500224700001500239700002100254700001700275856010900292 2005 eng d00aBiogeological Raman spectroscopic studies of Antarctic lacustrine sediments0 aBiogeological Raman spectroscopic studies of Antarctic lacustrin0 v611 aMoody, C1 aVillar, S1 aEdwards, H1 aHodgson, D1 aDoran, Peter, T.1 aBishop, J.L. uhttps://mcm.lternet.edu/content/biogeological-raman-spectroscopic-studies-antarctic-lacustrine-sediments00884nas a2200265 4500008004100000245007800041210007000119300001100189490000700200653002500207100002100232700001900253700002700272700002700299700002400326700002100350700001700371700001300388700002400401700002400425700002400449700002300473700002000496856010200516 2005 eng d00aComment on ``El Niño suppresses Antarctic warming'' by N. Bertler et al.0 aComment on El Niño suppresses Antarctic warming by N Bertler et  aL077060 v3210aTropical meteorology1 aDoran, Peter, T.1 aClow, Gary, D.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aParsons, Andrew, N.1 aPriscu, John, C.1 aLyons, Berry1 aWalsh, J1 aFountain, Andrew, G1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/comment-el-ni%C3%B1o-suppresses-antarctic-warming-n-bertler-et-al00618nas a2200181 4500008004100000245006900041210006800110300000900178490000700187100001700194700002100211700002400232700001400256700002300270700002100293700002400314856009800338 2005 eng d00aDating water and solute additions to ice-covered Antarctic lakes0 aDating water and solute additions to icecovered Antarctic lakes aA7200 v691 aLyons, Berry1 aDowling, Carolyn1 aWelch, Kathleen, A.1 aSnyder, G1 aPoreda, Robert, J.1 aDoran, Peter, T.1 aFountain, Andrew, G uhttps://mcm.lternet.edu/content/dating-water-and-solute-additions-ice-covered-antarctic-lakes00549nas a2200157 4500008004100000245009600041210006900137300001200206490000800218100002500226700002200251700002700273700001400300700002100314856005600335 2005 eng d00aGlacial ice cores: a model system for developing extraterrestrial decontamination protocols0 aGlacial ice cores a model system for developing extraterrestrial a572-5840 v1741 aChristner, Brent, C.1 aMikucki, Jill, A.1 aForeman, Christine, M.1 aDenson, J1 aPriscu, John, C. u/reports/lakes/ChristnerEtAl2005Decontamination.pdf00711nas a2200205 4500008004100000245008900041210006900130300001200199490000700211100001700218700002400235700002000259700002000279700002300299700002400322700002100346700001400367700001500381856010900396 2005 eng d00aGroundwater seeps in Taylor Valley Antarctica: An example of a subsurface melt event0 aGroundwater seeps in Taylor Valley Antarctica An example of a su a200-2060 v401 aLyons, Berry1 aWelch, Kathleen, A.1 aCarey, Anne, E.1 aWall, Diana, H.1 aVirginia, Ross, A.1 aFountain, Andrew, G1 aDoran, Peter, T.1 aCsatho, B1 aTremper, C uhttps://mcm.lternet.edu/content/groundwater-seeps-taylor-valley-antarctica-example-subsurface-melt-event00443nas a2200121 4500008004100000245005800041210005800099260003600157490001000193100001400203700002100217856008300238 2005 eng d00aLacustrine Biogeochemistry of the McMurdo Dry Valleys0 aLacustrine Biogeochemistry of the McMurdo Dry Valleys bUniversity of Illinois, Chicago0 vPh.D.1 aLawson, J1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/lacustrine-biogeochemistry-mcmurdo-dry-valleys00755nas a2200217 4500008004100000245008700041210006900128260003100197300001000228100002100238700002200259700002000281700002700301700001900328700002000347700002000367700002200387700001900409700001700428856009200445 2005 eng d00aPerennial Antarctic lake ice: A refuge for cyanobacteria in an extreme environment0 aPerennial Antarctic lake ice A refuge for cyanobacteria in an ex bPrinceton University Press a22-491 aPriscu, John, C.1 aAdams, Edward, E.1 aPaerl, Hans, W.1 aFritsen, Christian, H.1 aDore, John, E.1 aLisle, John, T.1 aWolf, Craig, F.1 aMikucki, Jill, A.1 aRogers, S., O.1 aCastello, J. uhttp://www.montana.edu/lkbonney/DOCS/Publications/PriscuEtAl2005CyanobacteriaRefuge.pdf00662nas a2200193 4500008004100000245008500041210006900126260004000195300001200235100002700247700002300274700001500297700001600312700002100328700002700349700002100376700002000397856005100417 2005 eng d00aPolar lakes, streams, and springs as analogs for the hydrological cycle on Mars.0 aPolar lakes streams and springs as analogs for the hydrological  aBerlin, HeidelbergbSpringer Verlag a219-2331 aMcKay, Christopher, P.1 aAndersen, Dale, T.1 aPollard, W1 aHeldmann, J1 aDoran, Peter, T.1 aFritsen, Christian, H.1 aPriscu, John, C.1 aTokano, Tetsuya u/reports/lakes/McKayEtAl2005StreamsSprings.pdf00875nas a2200361 4500008004100000245001800041210001800059260001700077300001200094100001900106700001500125700001500140700002300155700001300178700001300191700001900204700001500223700001400238700002000252700001500272700001400287700001700301700001800318700001900336700001400355700002200369700001400391700001500405700001500420700001600435700001200451856005000463 2005 eng d00aPolar Systems0 aPolar Systems bIsland Press a717-7431 aChapin, F., S.1 aMcGuire, A1 aNuttall, M1 aVirginia, Ross, A.1 aYoung, O1 aZimov, S1 aChristensen, T1 aGodduhn, A1 aMurphy, E1 aWall, Diana, H.1 aZockler, C1 aBerman, M1 aCallaghan, T1 aConvey, Peter1 aCrepin, A., S.1 aDanell, K1 aDucklow, Hugh, W.1 aForbes, B1 aKofinas, G1 aHassan, R.1 aScholes, R.1 aAsh, N. uhttps://mcm.lternet.edu/content/polar-systems00468nas a2200157 4500008004100000245002900041210002900070260003100099100001500130700002400145700002100169700001500190700002900205700001500234856006100249 2004 eng d00aAntarctic Paleolimnology0 aAntarctic Paleolimnology bKluwer Academic Publishers1 aHodgson, D1 aGibson, John, A. E.1 aDoran, Peter, T.1 aPienitz, R1 aDouglas, Marianne, S. V.1 aSmol, J.P. uhttps://mcm.lternet.edu/content/antarctic-paleolimnology00642nas a2200145 4500008004100000245014700041210006900188490000700257100001900264700001700283700002100300700002500321700002400346856012600370 2004 eng d00aThe Carbon Isotopic Composition of Dissolved Inorganic Carbon in Perennially Ice-Covered Antarctica Lakes: Searching for a Biogenic Signature.0 aCarbon Isotopic Composition of Dissolved Inorganic Carbon in Per0 v391 aNeumann, Klaus1 aLyons, Berry1 aPriscu, John, C.1 aDesMarais, David, J.1 aWelch, Kathleen, A. uhttps://mcm.lternet.edu/content/carbon-isotopic-composition-dissolved-inorganic-carbon-perennially-ice-covered-antarctica00523nas a2200121 4500008004100000245009800041210006900139490000800208100002200216700002400238700002100262856011800283 2004 eng d00aClimatology of Katabatic Winds in the McMurdo Dry Valleys, Southern Victoria Land, Antarctica0 aClimatology of Katabatic Winds in the McMurdo Dry Valleys Southe0 v1091 aNylen, Thomas, H.1 aFountain, Andrew, G1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/climatology-katabatic-winds-mcmurdo-dry-valleys-southern-victoria-land-antarctica00630nas a2200157 4500008004100000245011600041210006900157260001200226300001400238490000700252100002500259700002400284700002300308700001900331856012200350 2004 eng d00aDenitrification and hydrologic transient storage in a glacial meltwater stream, McMurdo Dry Valleys, Antarctica0 aDenitrification and hydrologic transient storage in a glacial me c09/2004 a1884-18950 v491 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aRunkel, Robert, L.1 aDuff, John, H. uhttps://mcm.lternet.edu/content/denitrification-and-hydrologic-transient-storage-glacial-meltwater-stream-mcmurdo-dry00811nas a2200301 4500008004100000245004900041210004700090300001200137490000600149100001300155700001300168700001900181700001700200700001200217700001200229700001200241700002300253700002000276700001400296700002300310700002500333700001200358700001500370700001500385700001400400700001600414856007900430 2004 eng d00aDetritus, trophic dynamics and biodiversity.0 aDetritus trophic dynamics and biodiversity a584-6000 v71 aMoore, J1 aMorin, P1 aNadelhoffer, K1 aRosemound, A1 aPost, D1 aSabo, J1 aScow, K1 aVanni, Michael, J.1 aWall, Diana, H.1 aBerlow, E1 aColeman, David, C.1 aDe Ruiter, Peter, C.1 aDong, Q1 aHasting, A1 aJohnson, N1 aMcCann, K1 aMelville, K uhttps://mcm.lternet.edu/content/detritus-trophic-dynamics-and-biodiversity00627nas a2200169 4500008004100000245010400041210006900145300001400214490000700228100001100235700002100246700001900267700001500286700001500301700001400316856012700330 2004 eng d00aElevated levels of dimethylated-sulfur compounds in Lake Bonney, a poorly ventilated Antarctic lake0 aElevated levels of dimethylatedsulfur compounds in Lake Bonney a a1044-10550 v491 aLee, P1 aPriscu, John, C.1 aDiTullio, G, R1 aRiseman, S1 aTursich, N1 aDeMora, S uhttps://mcm.lternet.edu/content/elevated-levels-dimethylated-sulfur-compounds-lake-bonney-poorly-ventilated-antarctic-lake00594nas a2200193 4500008004100000245005000041210005000091260003100141100001200172700001400184700001300198700001400211700002100225700001600246700001500262700002900277700001500306856007900321 2004 eng d00aGeochronology of high latitude lake sediments0 aGeochronology of high latitude lake sediments bKluwer Academic Publishers1 aWolf, A1 aMiller, G1 aOlsen, C1 aForman, S1 aDoran, Peter, T.1 aHolmgren, S1 aPienitz, R1 aDouglas, Marianne, S. V.1 aSmol, J.P. uhttps://mcm.lternet.edu/content/geochronology-high-latitude-lake-sediments00681nas a2200157 4500008004100000245015800041210006900199300001200268490000700280100002400287700002300311700001900334700002000353700002400373856012600397 2004 eng d00aInorganic nitrogen and phosphorus dynamics of Antarctic glacial meltwater streams as controlled by hyporheic exchange and benthic autotrophic communities0 aInorganic nitrogen and phosphorus dynamics of Antarctic glacial  a171-1880 v231 aMcKnight, Diane, M.1 aRunkel, Robert, L.1 aDuff, John, H.1 aTate, Cathy, M.1 aMoorhead, Daryl, L. uhttps://mcm.lternet.edu/content/inorganic-nitrogen-and-phosphorus-dynamics-antarctic-glacial-meltwater-streams-controlled00791nas a2200217 4500008004100000020002200041245008200063210006900145260005900214300001200273100002100285700002100306700001700327700001400344700002300358700002300381700001500404700002900419700001500448856011000463 2004 eng d a978-1-4020-2125-100aPaleolimnology of extreme cold terrestrial and extraterrestrial environments.0 aPaleolimnology of extreme cold terrestrial and extraterrestrial  aDordrecht, The NetherlandsbKluwer Academic Publishers a475-5071 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aPowell, R1 aPoreda, Robert, J.1 aAndersen, Dale, T.1 aPienitz, R1 aDouglas, Marianne, S. V.1 aSmol, J.P. uhttps://mcm.lternet.edu/content/paleolimnology-extreme-cold-terrestrial-and-extraterrestrial-environments00602nas a2200193 4500008004100000245004700041210004600088260003100134300001200165100002100177700002100198700001700219700001400236700002300250700001500273700002900288700001500317856007600332 2004 eng d00aPaleolimnology of Ice-covered Environments0 aPaleolimnology of Icecovered Environments bKluwer Academic Publishers a475-5071 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aPowell, R1 aPoreda, Robert, J.1 aPienitz, R1 aDouglas, Marianne, S. V.1 aSmol, John uhttps://mcm.lternet.edu/content/paleolimnology-ice-covered-environments00661nas a2200157 4500008004100000245015000041210006900191300001200260490000700272100001400279700002100293700001800314700002500332700002100357856012500378 2004 eng d00aStable carbon and nitrogen isotopic compositions of benthic and pelagic organic matter in four polar lakes of the McMurdo Dry Valleys, Antarctica0 aStable carbon and nitrogen isotopic compositions of benthic and  a269-3010 v101 aLawson, J1 aDoran, Peter, T.1 aKenig, Fabien1 aDesMarais, David, J.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/stable-carbon-and-nitrogen-isotopic-compositions-benthic-and-pelagic-organic-matter-four00726nas a2200205 4500008004100000245011200041210006900153300000900222490000700231100001100238700002200249700002700271700002100298700001900319700001500338700001400353700002000367700001400387856011900401 2004 eng d00aThermodynamic constraints on microbially mediated processes in lakes of the McMurdo Dry Valleys, Antarctica0 aThermodynamic constraints on microbially mediated processes in l a1-170 v211 aLee, P1 aMikucki, Jill, A.1 aForeman, Christine, M.1 aPriscu, John, C.1 aDiTullio, G, R1 aRiseman, S1 aDeMora, S1 aWolf, Craig, F.1 aKester, L uhttps://mcm.lternet.edu/content/thermodynamic-constraints-microbially-mediated-processes-lakes-mcmurdo-dry-valleys00681nas a2200205 4500008004100000245009300041210006900134300001200203490000600215100001600221700001700237700001500254700001500269700001300284700001200297700001400309700001300323700002000336856011900356 2004 eng d00aTrophic interactions in a changing world: modelling aboveground-belowground interactions0 aTrophic interactions in a changing world modelling abovegroundbe a515-5280 v51 aSchroter, D1 aBrussaard, L1 aDe Deyn, G1 aProveda, K1 aBrown, V1 aBerg, M1 aWardle, D1 aMoore, J1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/trophic-interactions-changing-world-modelling-aboveground-belowground-interactions00679nas a2200169 4500008004100000245011200041210006900153260001700222100002400239700001900263700001700282700002400299700002700323700001700350700001500367856012700382 2003 eng d00aChemistry and lake dynamics of the Taylor Valley lakes, Antarctica: The importance of long-term monitoring.0 aChemistry and lake dynamics of the Taylor Valley lakes Antarctic bCaxton Press1 aWelch, Kathleen, A.1 aNeumann, Klaus1 aLyons, Berry1 aMcKnight, Diane, M.1 aHoward-Williams, Clive1 aDavidson, W.1 aBroady, P. uhttps://mcm.lternet.edu/content/chemistry-and-lake-dynamics-taylor-valley-lakes-antarctica-importance-long-term-monitoring00482nas a2200121 4500008004100000245007500041210006900116260003600185490000900221100001300230700002100243856009600264 2003 eng d00aDistribution of 210Pb and 137Cs in the McMurdo Dry Valleys, Antarctica0 aDistribution of 210Pb and 137Cs in the McMurdo Dry Valleys Antar bUniversity of Illinois, Chicago0 vM.S.1 aOlsen, C1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/distribution-210pb-and-137cs-mcmurdo-dry-valleys-antarctica00567nas a2200169 4500008004100000245009200041210006900133260001200202300001000214490000800224100002100232700002700253700002700280700002100307700002200328856004700350 2003 eng d00aFormation and character of an ancient 19 m ice cover and underlying trapped brine in an0 aFormation and character of an ancient 19 m ice cover and underly c01/2003 a26-310 v1001 aDoran, Peter, T.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aPriscu, John, C.1 aAdams, Edward, E. uhttp://www.pnas.org/content/100/1/26.short00733nas a2200193 4500008004100000245014900041210006900190300001200259490000600271100001500277700002100292700001900313700001400332700001400346700001900360700001500379700002100394856012400415 2003 eng d00aFourier-transform raman spectroscopic studies of organic and inorganic chemical components in stromatolitic cores from Antarctic lake sediments0 aFouriertransform raman spectroscopic studies of organic and inor a325-3310 v11 aEdwards, H1 aWynn-Williams, D1 aEllis-Evans, J1 aNewton, E1 aLittle, S1 ade Oliveira, L1 aHodgson, D1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/fourier-transform-raman-spectroscopic-studies-organic-and-inorganic-chemical-components00682nas a2200169 4500008004100000245012300041210006900164300001200233490000700245100001700252700002400269700002400293700002000317700002200337700002400359856012900383 2003 eng d00aSurface glaciochemistry of Taylor Valley, southern Victoria Land, Antarctica and its relationship to stream chemistry.0 aSurface glaciochemistry of Taylor Valley southern Victoria Land  a115-1300 v171 aLyons, Berry1 aWelch, Kathleen, A.1 aFountain, Andrew, G1 aDana, Gayle, L.1 aVaughn, Bruce, H.1 aMcKnight, Diane, M. uhttps://mcm.lternet.edu/content/surface-glaciochemistry-taylor-valley-southern-victoria-land-antarctica-and-its-relationship00890nas a2200277 4500008004100000245006500041210006500106260001200171300001200183490000800195653002100203100002100224700002100245700001700266700002000283700002400303700002400327700002400351700002300375700002000398700001900418700002700437700002700464700002400491856009700515 2002 eng d00aAntarctic climate cooling and terrestrial ecosystem response0 aAntarctic climate cooling and terrestrial ecosystem response c01/2002 a517-5200 v41510aClimate Response1 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aWalsh, John, E.1 aFountain, Andrew, G1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aVirginia, Ross, A.1 aWall, Diana, H.1 aClow, Gary, D.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aParsons, Andrew, N. uhttps://mcm.lternet.edu/content/antarctic-climate-cooling-and-terrestrial-ecosystem-response00772nas a2200253 4500008004100000245004700041210004700088300001200135490000800147100002000155700001900175700002700194700002700221700002400248700002100272700002100293700001700314700002400331700002400355700002400379700002300403700002000426856007200446 2002 eng d00aRecent Temperature Trends in the Antarctic0 aRecent Temperature Trends in the Antarctic a291-2920 v4181 aWalsh, John, E.1 aClow, Gary, D.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aParsons, Andrew, N.1 aDoran, Peter, T.1 aPriscu, John, C.1 aLyons, Berry1 aFountain, Andrew, G1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/recent-temperature-trends-antarctic00540nas a2200145 4500008004100000245007900041210006900120300001400189490000700203100002000210700001300230700002400243700002400267856010300291 2002 eng d00aSatellite-Derived Indices of Stream Discharge in Taylor Valley,Antarctica.0 aSatelliteDerived Indices of Stream Discharge in Taylor ValleyAnt a1603-16160 v161 aDana, Gayle, L.1 aDavis, R1 aFountain, Andrew, G1 aWharton, Robert, A. uhttps://mcm.lternet.edu/content/satellite-derived-indices-stream-discharge-taylor-valleyantarctica00760nas a2200229 4500008004100000245012700041210006900168260001200237300001000249490000700259653001100266100002500277700002200302700002100324700002400345700001700369700002400386700001800410700002300428700002000451856005900471 2002 eng d00aSnow patch influence on soil biogeochemical processes and invertebrate distribution in the McMurdo Dry Valleys, Antarctica0 aSnow patch influence on soil biogeochemical processes and invert c02/2003 a91-990 v3510aBiggie1 aGooseff, Michael, N.1 aBarrett, John, E.1 aDoran, Peter, T.1 aFountain, Andrew, G1 aLyons, Berry1 aParsons, Andrew, N.1 aPorazinska, D1 aVirginia, Ross, A.1 aWall, Diana, H. uhttp://instaar.metapress.com/content/r086455ju7213711/03551nas a2200217 4500008004100000245009000041210006900131260001200200300001400212490000800226520282700234653001103061100002103072700002703093700001903120700002003139700002403159700002203183700001703205856011103222 2002 eng d00aValley floor climate observations from the McMurdo Dry Valleys, Antarctica, 1986-20000 aValley floor climate observations from the McMurdo Dry Valleys A c12/2002 a4772-47840 v1073 a

Climate observations from the McMurdo dry valleys, East Antarctica are presented from a network of seven valley floor automatic meteorological stations during the period 1986 to 2000. Mean annual temperatures ranged from −14.8°C to −30.0°C, depending on the site and period of measurement. Mean annual relative humidity is generally highest near the coast. Mean annual wind speed increases with proximity to the polar plateau. Site-to-site variation in mean annual solar flux and PAR is due to exposure of each station and changes over time are likely related to changes in cloudiness. During the nonsummer months, strong katabatic winds are frequent at some sites and infrequent at others, creating large variation in mean annual temperature owing to the warming effect of the winds. Katabatic wind exposure appears to be controlled to a large degree by the presence of colder air in the region that collects at low points and keeps the warm less dense katabatic flow from the ground. The strong influence of katabatic winds makes prediction of relative mean annual temperature based on geographical position (elevation and distance from the coast) alone, not possible. During the summer months, onshore winds dominate and warm as they progress through the valleys creating a strong linear relationship (r2 = 0.992) of increasing potential temperature with distance from the coast (0.09°C km−1). In contrast to mean annual temperature, summer temperature lends itself quite well to model predictions, and is used to construct a statistical model for predicting summer dry valley temperatures at unmonitored sites.

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aPriscu, John, C.1 aDonahoe, R uhttps://mcm.lternet.edu/content/co2-concentrations-perennially-ice-covered-lakes-taylor-valley-antarctica00462nas a2200121 4500008004100000245007200041210006900113300001200182490000700194100001900201700002100220856009900241 2001 eng d00aLuminescence zeroing tests in Lake Hoare, Taylor Valley, Antarctica0 aLuminescence zeroing tests in Lake Hoare Taylor Valley Antarctic a519-5290 v251 aBerger, G., W.1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/luminescence-zeroing-tests-lake-hoare-taylor-valley-antarctica00774nas a2200193 4500008004100000245014400041210006900185300001200254490000700266100001700273700002400290700002100314700002800335700002400363700002400387700002100411700002000432856012800452 2001 eng d00aThe McMurdo Dry Valleys Long-Term Ecological Research Program: new understanding of the biogeochemistry of the Dry Valley lakes: a review.0 aMcMurdo Dry Valleys LongTerm Ecological Research Program new und a202-2170 v251 aLyons, Berry1 aWelch, 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4500008004100000245012200041210006900163300001400232490000700246100001400253700001500267700002200282700001600304700001700320700001400337700001400351700001500365700001500380700001300395700001700408700002200425700002000447700001400467700002300481700001400504856012400518 2000 eng d00aInteractions between above and belowground biodiversity in terrestrial ecosystems: patterns, mechanisms and feedbacks0 aInteractions between above and belowground biodiversity in terre a1049-10610 v501 aHooper, D1 aLavelle, P1 avan der Putten, W1 aDeRuiter, P1 aRusek, Josef1 aSilver, W1 aTiedje, J1 aWolters, V1 aBignell, D1 aBrown, V1 aBrussaard, L1 aDangerfield, Mark1 aWall, Diana, H.1 aWardle, D1 aColeman, David, C.1 aGiller, K uhttps://mcm.lternet.edu/content/interactions-between-above-and-belowground-biodiversity-terrestrial-ecosystems-patterns00606nas a2200157 4500008004100000245008300041210006900124260001700193100002800210700002300238700002100261700002700282700001700309700001500326856010700341 2000 eng 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4500008004100000245008100041210006900122260001200191300001200203490000800215653001400223100002100237700001900258700001700277700002400294700002100318700001600339700001700355856010600372 1999 eng d00aDating quaternary lacustrine sediments in the McMurdo Dry Valleys Antarctica0 aDating quaternary lacustrine sediments in the McMurdo Dry Valley c03/1999 a223-2390 v14710asediments1 aDoran, Peter, T.1 aBerger, G., W.1 aLyons, Berry1 aWharton, Robert, A.1 aDavisson, M., L.1 aSouthon, J.1 aDibb, J., E. uhttps://mcm.lternet.edu/content/dating-quaternary-lacustrine-sediments-mcmurdo-dry-valleys-antarctica00521nas a2200145 4500008004100000245006200041210006200103100001700165700001600182700002400198700002100222700002300243700002300266856008600289 1999 eng d00aEffects of research diving on a stratified antarctic lake0 aEffects of research diving on a stratified antarctic lake1 aKepner, R.L.1 aKortyna, A.1 aWharton, Robert, A.1 aDoran, Peter, T.1 aAndersen, Dale, T.1 aRoberts, Emily, C. uhttps://mcm.lternet.edu/content/effects-research-diving-stratified-antarctic-lake00514nas a2200109 4500008004100000245006200041210006000103260010700163100002400270700002100294856008900315 1999 eng d00aMcMurdo Dry Valley Lakes: Impacts of Research Activities.0 aMcMurdo Dry Valley Lakes Impacts of Research Activities bDesert Research Institute, University and Community College System of Nevada, USA, special publication1 aWharton, Robert, A.1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/mcmurdo-dry-valley-lakes-impacts-research-activities00878nas a2200277 4500008004100000245006500041210006400106260001200170300001200182490000700194653002300201100002400224700001700248700002400265700002000289700002100309700002100330700002400351700002400375700002400399700002100423700002000444700002400464700002300488856008900511 1999 eng d00aPhysical controls on the Taylor Valley Ecosystem, Antarctica0 aPhysical controls on the Taylor Valley Ecosystem Antarctica c12/1999 a961-9720 v4910aWater availability1 aFountain, Andrew, G1 aLyons, Berry1 aBurkins, Melody, B.1 aDana, Gayle, L.1 aDoran, Peter, T.1 aLewis, Karen, J.1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aParsons, Andrew, N.1 aPriscu, John, C.1 aWall, Diana, H.1 aWharton, Robert, A.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/physical-controls-taylor-valley-ecosystem-antarctica00570nas a2200157 4500008004100000245007400041210006900115260001200184300001600196490000800212100002100220700002400241700002500265700002700290856009500317 1998 eng d00aAntarctic paleolake sediments and the search for extinct life on Mars0 aAntarctic paleolake sediments and the search for extinct life on c05/1998 a28481-284930 v1031 aDoran, Peter, T.1 aWharton, Robert, A.1 aDesMarais, David, J.1 aMcKay, Christopher, P. uhttps://mcm.lternet.edu/content/antarctic-paleolake-sediments-and-search-extinct-life-mars00540nas a2200133 4500008004100000245009300041210006900134300001200203490000700215100002100222700002400243700002000267856011900287 1998 eng d00aEnergy balance studies of Canada Glacier, Taylor Valley, McMurdo Dry Valleys, Antarctica0 aEnergy balance studies of Canada Glacier Taylor Valley McMurdo D a603-6090 v271 aLewis, Karen, J.1 aFountain, Andrew, G1 aDana, Gayle, L. uhttps://mcm.lternet.edu/content/energy-balance-studies-canada-glacier-taylor-valley-mcmurdo-dry-valleys-antarctica00605nas a2200169 4500008004100000245008000041210006900121300001200190490000700202100002100209700002000230700001900250700002200269700002100291700001700312856010600329 1998 eng d00aEvidence of deep circulation in two perennially ice-covered Antarctic lakes0 aEvidence of deep circulation in two perennially icecovered Antar a625-6350 v431 aTyler, Scott, W.1 aCook, Peter, G.1 aButt, Anya, Z.1 aThomas, James, M.1 aDoran, Peter, T.1 aLyons, Berry uhttps://mcm.lternet.edu/content/evidence-deep-circulation-two-perennially-ice-covered-antarctic-lakes00571nas a2200157 4500008004100000245007600041210006900117300001000186490000700196100002400203700002000227700002100247700002200268700002400290856009900314 1998 eng d00aGlaciers of the McMurdo Dry Valleys, Southern Victoria Land, Antarctica0 aGlaciers of the McMurdo Dry Valleys Southern Victoria Land Antar a65-750 v721 aFountain, Andrew, G1 aDana, Gayle, L.1 aLewis, Karen, J.1 aVaughn, Bruce, H.1 aMcKnight, Diane, M. uhttps://mcm.lternet.edu/content/glaciers-mcmurdo-dry-valleys-southern-victoria-land-antarctica00591nas a2200145 4500008004100000245010800041210006900149260001200218300001200230490000700242100002100249700002400270700002400294856012700318 1998 eng d00aMcMurdo Dry Valleys LTER: Geophysical determination of bathymetry and morphology of Taylor Valley lakes0 aMcMurdo Dry Valleys LTER Geophysical determination of bathymetry c01/1996 a198-2000 v311 aDoran, Peter, T.1 aWharton, Robert, A.1 aSchmok, Jeffrey, P. uhttps://mcm.lternet.edu/content/mcmurdo-dry-valleys-lter-geophysical-determination-bathymetry-and-morphology-taylor-valley00538nas a2200121 4500008004100000245012400041210006900165300001200234490000700246100001900253700002100272856012300293 1998 eng d00aMcMurdo Dry Valleys LTER: Phosphorus deficiency and alkaline phosphatase activity in lakes of Taylor Valley, Antarctica0 aMcMurdo Dry Valleys LTER Phosphorus deficiency and alkaline phos a206-2080 v311 aDore, John, E.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/mcmurdo-dry-valleys-lter-phosphorus-deficiency-and-alkaline-phosphatase-activity-lakes00529nas a2200133 4500008004100000245008700041210006900128300001200197490000700209100002000216700002400236700002400260856011100284 1998 eng d00aMcMurdo Dry Valleys LTER: Solar radiation on glaciers in Taylor Valley, Antarctica0 aMcMurdo Dry Valleys LTER Solar radiation on glaciers in Taylor V a191-1930 v311 aDana, Gayle, L.1 aWharton, Robert, A.1 aFountain, Andrew, G uhttps://mcm.lternet.edu/content/mcmurdo-dry-valleys-lter-solar-radiation-glaciers-taylor-valley-antarctica00554nas a2200133 4500008004100000245010100041210006900142300001200211490000700223100002400230700002100254700002000275856012500295 1998 eng d00aMcMurdo Dry Valleys LTER: Spatial variation of glacier mass balance in Taylor Valley, Antarctica0 aMcMurdo Dry Valleys LTER Spatial variation of glacier mass balan a194-1950 v311 aFountain, Andrew, G1 aLewis, Karen, J.1 aDana, Gayle, L. uhttps://mcm.lternet.edu/content/mcmurdo-dry-valleys-lter-spatial-variation-glacier-mass-balance-taylor-valley-antarctica00762nas a2200241 4500008004100000245007100041210006900112260001200181300001400193490000800207653001100215100002100226700002700247700002200274700002800296700002000324700002700344700002100371700002400392700002200416700002400438856005800462 1998 eng d00aPerennial Antarctic Lake Ice: An Oasis for Life in a Polar Desert0 aPerennial Antarctic Lake Ice An Oasis for Life in a Polar Desert c06/1998 a2095-20980 v28010aBiggie1 aPriscu, John, C.1 aFritsen, Christian, H.1 aAdams, Edward, E.1 aGiovannoni, Stephen, J.1 aPaerl, Hans, W.1 aMcKay, Christopher, P.1 aDoran, Peter, T.1 aGordon, Douglas, A.1 aLanoil, Brian, D.1 aPinckney, James, L. uhttp://www.sciencemag.org/content/280/5372/2095.short00452nas a2200133 4500008004100000245005900041210005800100300001000158490000700168100002000175700002400195700001600219856008300235 1998 eng d00aSolar Radiation in the McMurdo Dry Valleys, Antarctica0 aSolar Radiation in the McMurdo Dry Valleys Antarctica a39-640 v721 aDana, Gayle, L.1 aWharton, Robert, A.1 aDubayah, R. uhttps://mcm.lternet.edu/content/solar-radiation-mcmurdo-dry-valleys-antarctica00569nas a2200121 4500008004100000245013800041210006900179260002600248490000900274100001300283700002400296856012700320 1998 eng d00aSpatial-temporal patterns of primary production in phytoplankton communities of Taylor Valley lakes, Antartica: A modelling synthesis0 aSpatialtemporal patterns of primary production in phytoplankton  bTexas Tech University0 vM.S.1 aDavis, W1 aMoorhead, Daryl, L. uhttps://mcm.lternet.edu/content/spatial-temporal-patterns-primary-production-phytoplankton-communities-taylor-valley-lakes00560nas a2200133 4500008004100000245010400041210006900145300001200214490000700226100002100233700002400254700002000278856012800298 1998 eng d00aSurface energy balance and meltwater production for a Dry Valley glacier, Taylor Valley, Antarctica0 aSurface energy balance and meltwater production for a Dry Valley a603-6090 v271 aLewis, Karen, J.1 aFountain, Andrew, G1 aDana, Gayle, L. uhttps://mcm.lternet.edu/content/surface-energy-balance-and-meltwater-production-dry-valley-glacier-taylor-valley-antarctica00672nas a2200181 4500008004100000245007800041210006900119260005900188300001000247100002000257700001300277700002400290700002400314700001900338700001600357700001600373856010100389 1998 eng d00aA Temperature area index of stream discharge in Taylor Valley, Antarctica0 aTemperature area index of stream discharge in Taylor Valley Anta bNational Water Research Institute , Environment Canada a29-391 aDana, Gayle, L.1 aDavis, R1 aFountain, Andrew, G1 aWharton, Robert, A.1 aPietroniro, A.1 aGranger, R.1 aPultz, T.J. uhttps://mcm.lternet.edu/content/temperature-area-index-stream-discharge-taylor-valley-antarctica00625nas a2200205 4500008004100000245005100041210005100092300001200143490000700155100001700162700002900179700002300208700001600231700001500247700001800262700001600280700002400296700001900320856008000339 1997 eng d00aBiodiversity and Ecosystem Functioning in Soil0 aBiodiversity and Ecosystem Functioning in Soil a563-5700 v261 aBrussaard, L1 aBehan-Pelletier, Valerie1 aBignell, David, E.1 aBrown, V.K.1 aDidden, W.1 aFolgarait, P.1 aFragoso, C.1 aFreckman, Diana, W.1 aGupt, V.V.S.R. uhttps://mcm.lternet.edu/content/biodiversity-and-ecosystem-functioning-soil00661nas a2200169 4500008004100000245009900041210006900140260002900209300001200238100002400250700001700274700002400291700001700315700002700332700001500359856011700374 1997 eng d00aCarbon dynamics of aquatic microbial mats in the Antarctic dry valleys: A modelling synthesis0 aCarbon dynamics of aquatic microbial mats in the Antarctic dry v bBalkema Press, Rotterdam a181-1961 aMoorhead, Daryl, L.1 aDavis, Shane1 aWharton, Robert, A.1 aLyons, Berry1 aHoward-Williams, Clive1 aHawes, Ian uhttps://mcm.lternet.edu/content/carbon-dynamics-aquatic-microbial-mats-antarctic-dry-valleys-modelling-synthesis00670nas a2200181 4500008004100000245009200041210006900133260002900202300001200231100001700243700002200260700002300282700002100305700001700326700002700343700001500370856010300385 1997 eng d00aClimate history of the McMurdo Dry Valleys since the last glacial maximum: A synthesis0 aClimate history of the McMurdo Dry Valleys since the last glacia bBalkema Press, Rotterdam a155-1621 aLyons, Berry1 aBartek, Louis, R.1 aMayewski, Paul, A.1 aDoran, Peter, T.1 aLyons, Berry1 aHoward-Williams, Clive1 aHawes, Ian uhttps://mcm.lternet.edu/content/climate-history-mcmurdo-dry-valleys-last-glacial-maximum-synthesis00640nas a2200145 4500008004100000245015200041210006900193300001200262490000700274100002500281700002400306700001900330700002100349856012400370 1997 eng d00aDiatoms in sediments of perennially ice-covered Lake Hoare, and implications for interpreting lake history in the McMurdo Dry Valleys of Antarctica0 aDiatoms in sediments of perennially icecovered Lake Hoare and im a403-4200 v171 aSpaulding, Sarah, A.1 aMcKnight, Diane, M.1 aStoermer, E.F.1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/diatoms-sediments-perennially-ice-covered-lake-hoare-and-implications-interpreting-lake00516nas a2200133 4500008004100000245008200041210006900123260001100192300001200203100002000215700001700235700002400252856010600276 1997 eng d00aSatellite-derived surface temperatures in the McMurdo Dry Valleys, Antarctica0 aSatellitederived surface temperatures in the McMurdo Dry Valleys bDeepak a530-5331 aDana, Gayle, L.1 aWetzel, M.A.1 aWharton, Robert, A. uhttps://mcm.lternet.edu/content/satellite-derived-surface-temperatures-mcmurdo-dry-valleys-antarctica00795nas a2200193 4500008004100000245015600041210006900197260002900266300001200295100002000307700002000327700002400347700001900371700002500390700001700415700002700432700001500459856012700474 1997 eng d00aSpecies composition and primary production of algal communities in Dry Valley streams in Antarctica: Examination of the functional role of biodiversity0 aSpecies composition and primary production of algal communities  bBalkema Press, Rotterdam a171-1791 aNiyogi, Dev, K.1 aTate, Cathy, M.1 aMcKnight, Diane, M.1 aDuff, John, H.1 aAlger, Alexander, S.1 aLyons, Berry1 aHoward-Williams, Clive1 aHawes, Ian uhttps://mcm.lternet.edu/content/species-composition-and-primary-production-algal-communities-dry-valley-streams-antarctica00527nas a2200133 4500008004100000245008300041210006900124300001400193490000700207100002100214700002400235700002700259856010700286 1996 eng d00aExtreme Supersaturation of Nitrous Oxide in a Poorly Ventilated Antarctic Lake0 aExtreme Supersaturation of Nitrous Oxide in a Poorly Ventilated  a1544-15510 v411 aPriscu, John, C.1 aDownes, Malcolm, T.1 aMcKay, Christopher, P. uhttps://mcm.lternet.edu/content/extreme-supersaturation-nitrous-oxide-poorly-ventilated-antarctic-lake00623nas a2200157 4500008004100000245009800041210006900139300001200208490000700220100002000227700002500247700001800272700002300290700002400313856012800337 1996 eng d00aMicrocosms and Soil Ecology: Critical Linkages Between Field Studies and Modelling Food Webs0 aMicrocosms and Soil Ecology Critical Linkages Between Field Stud a694-7050 v771 aMoore, John, C.1 aDe Ruiter, Peter, C.1 aHunt, William1 aColeman, David, C.1 aFreckman, Diana, W. uhttps://mcm.lternet.edu/content/microcosms-and-soil-ecology-critical-linkages-between-field-studies-and-modelling-food-webs00487nas a2200121 4500008004100000245006700041210006600108260004000174490001000214100002100224700002400245856009600269 1996 eng d00aPaleolimnology of Perenially Ice-Covered Antarctic Oasis Lakes0 aPaleolimnology of Perenially IceCovered Antarctic Oasis Lakes aReno, NVbUniversity of Nevada Reno0 vPh.D.1 aDoran, Peter, T.1 aWharton, Robert, A. uhttps://mcm.lternet.edu/content/paleolimnology-perenially-ice-covered-antarctic-oasis-lakes00519nas a2200145 4500008004100000245005300041210005300094260004900147100001600196700002400212700002400236700001800260700001600278856007900294 1996 eng d00aSoil invertebrates as indicators of soil quality0 aSoil invertebrates as indicators of soil quality aMadison, WIbSoil Science Society of America1 aBlair, J.M.1 aBohlen, Patrick, J.1 aFreckman, Diana, W.1 aDoran, J., W.1 aJones, A.J. uhttps://mcm.lternet.edu/content/soil-invertebrates-indicators-soil-quality00378nas a2200109 4500008004100000245005700041210005400098300000600152490000600158100002100164856008300185 1996 eng d00aA weather network in McMurdo Dry Valleys, Antarctica0 aweather network in McMurdo Dry Valleys Antarctica a30 v71 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/weather-network-mcmurdo-dry-valleys-antarctica00596nas a2200145 4500008004100000245010000041210006900141300001200210490000700222100002100229700002000250700002900270700002400299856012700323 1995 eng d00aMcMurdo Dry Valleys Long-Term Ecological Research (LTER): LTER automatic weather network (LAWN)0 aMcMurdo Dry Valleys LongTerm Ecological Research LTER LTER autom a276-2800 v301 aDoran, Peter, T.1 aDana, Gayle, L.1 aHastings, Jordan, Towner1 aWharton, Robert, A. uhttps://mcm.lternet.edu/content/mcmurdo-dry-valleys-long-term-ecological-research-lter-lter-automatic-weather-network-lawn00544nas a2200145 4500008004100000245008200041210006900123300001200192490000700204100002100211700002000232700002100252700002400273856010100297 1995 eng d00aMcMurdo LTER: The surface-energy balance of the Canada Glacier, Taylor Valley0 aMcMurdo LTER The surfaceenergy balance of the Canada Glacier Tay a280-2820 v301 aLewis, Karen, J.1 aDana, Gayle, L.1 aTyler, Scott, W.1 aFountain, Andrew, G uhttps://mcm.lternet.edu/content/mcmurdo-lter-surface-energy-balance-canada-glacier-taylor-valley00501nas a2200121 4500008004100000245009300041210006900134300001200203490000700215100002400222700002100246856011200267 1995 eng d00aProfiles of electrode potential and dissolved oxygen in lakes of the McMurdo Dry Valleys0 aProfiles of electrode potential and dissolved oxygen in lakes of a305-3070 v301 aDownes, Malcolm, T.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/profiles-electrode-potential-and-dissolved-oxygen-lakes-mcmurdo-dry-valleys00492nas a2200133 4500008004100000245006900041210006700110300001200177490000700189100002400196700002200220700002000242856009600262 1994 eng d00aMcMurdo LTER: Glacier mass balances of Taylor Valley, Antarctica0 aMcMurdo LTER Glacier mass balances of Taylor Valley Antarctica a226-2280 v291 aFountain, Andrew, G1 aVaughn, Bruce, H.1 aDana, Gayle, L. uhttps://mcm.lternet.edu/content/mcmurdo-lter-glacier-mass-balances-taylor-valley-antarctica00506nas a2200145 4500008004100000245006200041210006000103300001200163490000700175100002100182700002400203700002500227700001900252856008900271 1994 eng d00aMcMurdo LTER: Paleolimnology of Taylor Valley, Antarctica0 aMcMurdo LTER Paleolimnology of Taylor Valley Antarctica a234-2370 v291 aDoran, Peter, T.1 aWharton, Robert, A.1 aSpaulding, Sarah, A.1 aFoster, J., S. uhttps://mcm.lternet.edu/content/mcmurdo-lter-paleolimnology-taylor-valley-antarctica00562nas a2200133 4500008004100000245011400041210006900155300001200224490000700236100002000243700002000263700002200283856012300305 1994 eng d00aMcMurdo LTER: Using narrow band spectroradiometry to assess algal and moss communities in a dry valley stream0 aMcMurdo LTER Using narrow band spectroradiometry to assess algal a232-2340 v291 aDana, Gayle, L.1 aTate, Cathy, M.1 aDewey, Sharon, L. uhttps://mcm.lternet.edu/content/mcmurdo-lter-using-narrow-band-spectroradiometry-assess-algal-and-moss-communities-dry00452nas a2200133 4500008004100000245005800041210005700099300001100156490000700167100002100174700002400195700001700219856008200236 1994 eng d00aPaleolimnology of the McMurdo Dry Valleys, Antarctica0 aPaleolimnology of the McMurdo Dry Valleys Antarctica a85-1140 v101 aDoran, Peter, T.1 aWharton, Robert, A.1 aLyons, Berry uhttps://mcm.lternet.edu/content/paleolimnology-mcmurdo-dry-valleys-antarctica00576nas a2200145 4500008004100000245009000041210006900131300001200200490000700212100002500219700002400244700002300268700002100291856011800312 1994 eng d00aPhytoplankton population dynamics in perennially ice-covered Lake Fryxell, Antarctica0 aPhytoplankton population dynamics in perennially icecovered Lake a527-5410 v161 aSpaulding, Sarah, A.1 aMcKnight, Diane, M.1 aSmith, Richard, L.1 aDufford, Richard uhttps://mcm.lternet.edu/content/phytoplankton-population-dynamics-perennially-ice-covered-lake-fryxell-antarctica00554nas a2200133 4500008004100000245010200041210006900143300001200212490000700224100002100231700001900252700002400271856012500295 1993 eng d00aWater column transformations of nitrogen in Lake Bonney, a perennially ice-covered antarctic lake0 aWater column transformations of nitrogen in Lake Bonney a perenn a237-2390 v281 aPriscu, John, C.1 aWard, Bess, B.1 aDownes, Malcolm, T. uhttps://mcm.lternet.edu/content/water-column-transformations-nitrogen-lake-bonney-perennially-ice-covered-antarctic-lake00513nas a2200121 4500008004100000245010000041210006900141300001000210490000800220100002200228700002100250856012000271 1990 eng d00aDevelopment and Application of a Technique for Estimating Nutrient Deficiency in Soft Sediments0 aDevelopment and Application of a Technique for Estimating Nutrie a93-970 v2031 aDodds, Walter, K.1 aPriscu, John, C. uhttps://mcm.lternet.edu/content/development-and-application-technique-estimating-nutrient-deficiency-soft-sediments