@article {4940, title = {McMurdo Dry Valley lake edge {\textquoteleft}moats{\textquoteright}: The ecological intersection between terrestrial and aquatic polar desert habitat}, journal = {Antarctic Science}, year = {2024}, month = {04/2024}, pages = {1 - 17}, abstract = {

Aquatic ecosystems - lakes, ponds and streams - are hotspots of biodiversity in the cold and arid environment of Continental Antarctica. Environmental change is expected to increasingly alter Antarctic aquatic ecosystems and modify the physical characteristics and interactions within the habitats that they support. Here, we describe physical and biological features of the peripheral \‘moat\’ of a closed-basin Antarctic lake. These moats mediate connectivity amongst streams, lake and soils. We highlight the cyclical moat transition from a frozen winter state to an active open-water summer system, through refreeze as winter returns. Summer melting begins at the lakebed, initially creating an ice-constrained lens of liquid water in November, which swiftly progresses upwards, creating open water in December. Conversely, freezing progresses slowly from the water surface downwards, with water at 1 m bottom depth remaining liquid until May. Moats support productive, diverse benthic communities that are taxonomically distinct from those under the adjacent permanent lake ice. We show how ion ratios suggest that summer exchange occurs amongst moats, streams, soils and sub-ice lake water, perhaps facilitated by within-moat density-driven convection. Moats occupy a small but dynamic area of lake habitat, are disproportionately affected by recent lake-level rises and may thus be particularly vulnerable to hydrological change.

}, keywords = {LTER-MCM, connectivity, ecosystem, ice, microbial mats, transition}, issn = {0954-1020}, doi = {10.1017/S0954102024000087}, url = {https://www.cambridge.org/core/journals/antarctic-science/article/mcmurdo-dry-valley-lake-edge-moats-the-ecological-intersection-between-terrestrial-and-aquatic-polar-desert-habitats/31D94DD51E651603482A3AE6E8A52A57}, author = {Stone, Michael S. and Devlin, Shawn and Ian Hawes and Kathleen A. Welch and Michael N. Gooseff and Cristina D. Takacs-Vesbach and Rachael M. Morgan-Kiss and Byron Adams and John E. Barrett and John C. Priscu and Peter T. Doran} } @article {4841, title = {Postglacial adaptations enabled colonization and quasi-clonal dispersal of ammonia-oxidizing archaea in modern European large lakes}, journal = {Science Advances}, volume = {9}, year = {2023}, month = {02/2023}, pages = {eadc9392}, abstract = {

Ammonia-oxidizing archaea (AOA) play a key role in the aquatic nitrogen cycle. Their genetic diversity is viewed as the outcome of evolutionary processes that shaped ancestral transition from terrestrial to marine habitats. However, current genome-wide insights into AOA evolution rarely consider brackish and freshwater representatives or provide their divergence timeline in lacustrine systems. An unbiased global assessment of lacustrine AOA diversity is critical for understanding their origins, dispersal mechanisms, and ecosystem roles. Here, we leveraged continental-scale metagenomics to document that AOA species diversity in freshwater systems is remarkably low compared to marine environments. We show that the uncultured freshwater AOA, \“Candidatus Nitrosopumilus limneticus,\” is ubiquitous and genotypically static in various large European lakes where it evolved 13 million years ago. We find that extensive proteome remodeling was a key innovation for freshwater colonization of AOA. These findings reveal the genetic diversity and adaptive mechanisms of a keystone species that has survived clonally in lakes for millennia.

}, keywords = {LTER-MCM}, doi = {10.1126/sciadv.adc9392}, url = {https://www.science.org/doi/10.1126/sciadv.adc9392}, author = {Ngugi, David Kamanda and Salcher, Michaela M. and Andrei, Adrian-Stefan and Ghai, Rohit and Klotz, Franziska and Chiriac, Maria-Cecilia and Ionescu, Danny and B{\"u}sing, Petra and Grossart, Hans-Peter and Xing, Peng and John C. Priscu and Alymkulov, Salmor and Pester, Michael} } @article {4866, title = {Sediment oxygen consumption in Antarctic subglacial environments}, journal = {Limnology and Oceanography}, volume = {68}, year = {2023}, month = {07/2023}, pages = {1557 - 1566}, abstract = {

Oxygen consumption in aquatic sediments is an indicator of overall biological activity of the ecosystem. As such, rates of sedimentary oxygen utilization are well documented for much of the open oceans and freshwater lakes. However, there are few direct measurements of sedimentary oxygen consumption from Antarctic subglacial aquatic sediments. We report the first microsensor oxygen profiles and derived sedimentary oxygen consumption rates from beneath the Ross Ice Shelf and a subglacial lake beneath the West Antarctic Ice Sheet. Rates of oxygen consumption in these two environments are relatively low, but comparable to those reported from ice-free polar oceans and oligotrophic Arctic lakes. Our study demonstrates the presence of oxygen within Antarctic subglacial aquatic sediments and its importance for oxygen-consuming microorganisms living in these ecosystems.

}, keywords = {LTER-MCM}, issn = {0024-3590}, doi = {10.1002/lno.12366}, url = {https://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lno.12366}, author = {Alexander B. Michaud and John C. Priscu} } @article {4814, title = {Antarctic lake phytoplankton and bacteria from near-surface waters exhibit high sensitivity to climate-driven disturbance}, journal = {Environmental Microbiology}, year = {2022}, month = {07/2022}, abstract = {

The McMurdo Dry Valleys (MDVs), Antarctica, represent a cold, desert ecosystem poised on the threshold of melting and freezing water. The MDVs have experienced dramatic signs of climatic change, most notably a warm austral summer in 2001\–2002 that caused widespread flooding, partial ice cover loss and lake level rise. To understand the impact of these climatic disturbances on lake microbial communities, we simulated lake level rise and ice-cover loss by transplanting dialysis-bagged communities from selected depths to other locations in the water column or to an open water perimeter moat. Bacteria and eukaryote communities residing in the surface waters (5 m) exhibited shifts in community composition when exposed to either disturbance, while microbial communities from below the surface were largely unaffected by the transplant. We also observed an accumulation of labile dissolved organic carbon in the transplanted surface communities. In addition, there were taxa-specific sensitivities: cryptophytes and Actinobacteria were highly sensitive particularly to the moat transplant, while chlorophytes and several bacterial taxa increased in relative abundance or were unaffected. Our results reveal that future climate-driven disturbances will likely undermine the stability and productivity of MDV lake phytoplankton and bacterial communities in the surface waters of this extreme environment.

}, keywords = {LTER-MCM}, doi = {10.1111/1462-2920.16113}, url = {https://onlinelibrary.wiley.com/doi/10.1111/1462-2920.16113}, author = {Sherwell, Shasten S. and Kalra, Isha and Li, Wei and Diane M. McKnight and John C. Priscu and Rachael M. Morgan-Kiss} } @article {4714, title = {Barotropic seiches in a perennially ice-covered lake, East Antarctica}, journal = {Limnology and Oceanography Letters}, volume = {7}, year = {2022}, month = {02/2022}, pages = {26 - 33}, abstract = {

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.

}, keywords = {LTER-MCM}, issn = {2378-2242}, doi = {10.1002/lol2.10226}, url = {https://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lol2.10226}, author = {Castendyk, Devin and Hilary A. Dugan and Gallagher, Hugh A. and Pujara, Nimish and Peter T. Doran and John C. Priscu and W. Berry Lyons} } @article {4776, title = {Organic matter distribution in the icy environments of Taylor Valley, Antarctica}, journal = {Science of The Total Environment}, volume = {841}, year = {2022}, month = {10/2022}, pages = {156639}, abstract = {

Glaciers can accumulate and release organic matter affecting the structure and function of associated terrestrial and aquatic ecosystems. We analyzed 18 ice cores collected from six locations in Taylor Valley (McMurdo Dry Valleys), Antarctica to determine the spatial abundance and quality of organic matter, and the spatial distribution of bacterial density and community structure from the terminus of the Taylor Glacier to the coast (McMurdo Sound). Our results showed that dissolved and particulate organic carbon (DOC and POC) concentrations in the ice core samples increased from the Taylor Glacier to McMurdo Sound, a pattern also shown by bacterial cell density. Fluorescence Excitation Emission Matrices Spectroscopy (EEMs) and multivariate parallel factor (PARAFAC) modeling identified one humic-like (C1) and one protein-like (C2) component in ice cores whose fluorescent intensities all increased from the Polar Plateau to the coast. The fluorescence index showed that the bioavailability of dissolved organic matter (DOM) also decreased from the Polar Plateau to the coast. Partial least squares path modeling analysis revealed that bacterial abundance was the main positive biotic factor influencing both the quantity and quality of organic matter. Marine aerosol influenced the spatial distribution of DOC more than katabatic winds in the ice cores. Certain bacterial taxa showed significant correlations with DOC and POC concentrations. Collectively, our results show the tight connectivity among organic matter spatial distribution, bacterial abundance and meteorology in the McMurdo Dry Valley ecosystem.

}, keywords = {LTER-MCM, Antarctica, bacteria, ice cores, katabatic wind, marine aerosol, organic matter}, issn = {00489697}, doi = {10.1016/j.scitotenv.2022.156639}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0048969722037366}, author = {Guo, Bixi and Li, Wei and Santib{\'a}{\~n}ez, Pamela and John C. Priscu and Liu, Yongqin and Liu, Keshao} } @article {4768, title = {Patterns and trends of organic matter processing and transport: Insights from the US Long-term Ecological Research Network}, journal = {Climate Change Ecology}, volume = {2}, year = {2021}, month = {12/2021}, pages = {100025}, abstract = {

Organic matter (OM) dynamics determine how much carbon is stored in ecosystems, a service that modulates climate. We synthesized research from across the US Long-Term Ecological Research (LTER) Network to assemble a conceptual model of OM dynamics that is consistent with inter-disciplinary perspectives and emphasizes vulnerability of OM pools to disturbance. Guided by this conceptual model, we identified unanticipated patterns and long-term trends in processing and transport of OM emerging from terrestrial, freshwater, wetland, and marine ecosystems. Cross-ecosystem synthesis combined with a survey of researchers revealed several themes: 1) strong effects of climate change on OM dynamics, 2) surprising patterns in OM storage and dynamics resulting from coupling with nutrients, 3) characteristic and often complex legacies of land use and disturbance, 4) a significant role of OM transport that is often overlooked in terrestrial ecosystems, and 5) prospects for reducing uncertainty in forecasting OM dynamics by incorporating the chemical composition of OM. Cross-fertilization of perspectives and approaches across LTER sites and other research networks can stimulate the comprehensive understanding required to support large-scale characterizations of OM budgets and the role of ecosystems in regulating global climate.

}, keywords = {LTER-MCM, coupled biogeochemical cycles, cross-site synthesis, organic matter composition, organic matter storage, stabilization, transport}, issn = {26669005}, doi = {10.1016/j.ecochg.2021.100025}, url = {https://www.sciencedirect.com/science/article/pii/S2666900521000253}, author = {Harms, Tamara K. and Groffman, Peter M. and Aluwihare, Lihini and Craft, Christopher and Wieder, William R and Hobbie, S and Baer, Sara G. and J.M. Blair and Frey, Serita D. and Remucal, Christina K. and Rudgers, Jennifer A. and Collins, SL and Kominoski, John S. and Ball, Becky and John C. Priscu and John E. Barrett} } @article {4613, title = {Year-round and long-term phytoplankton dynamics in Lake Bonney, a permanently ice-covered Antarctic lake}, journal = {Journal of Geophysical Research: Biogeosciences}, volume = {126}, year = {2021}, month = {04/2021}, pages = {e2020JG005925}, abstract = {

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).

}, keywords = {LTER-MCM, algae, Antarctic, fluorometry, ice, lakes, light, profiling, winter}, issn = {2169-8953}, doi = {10.1029/2020JG005925}, url = {https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JG005925}, author = {Patriarche, Jeffrey D. and John C. Priscu and Cristina D. Takacs-Vesbach and Winslow, Luke A. and Myers, Krista F. and Heather N. Buelow and Rachael M. Morgan-Kiss and Peter T. Doran} } @article {4297, title = {Methane production in the oxygenated water column of a perennially ice-covered Antarctic lake}, journal = {Limnology and Oceanography}, volume = {65}, year = {2020}, month = {01/2020}, abstract = {

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.

}, keywords = {LTER-MCM}, doi = {10.1002/lno.11257}, url = {https://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lno.11257}, author = {Li, Wei and John E. Dore and Steigmeyer, August J. and Cho, Yong-Joon and Kim, Ok-Sun and Liu, Yongqin and Rachael M. Morgan-Kiss and Skidmore, Mark L. and John C. Priscu} } @article {4403, title = {Subglacial brine flow and wind-induced internal waves in Lake Bonney, Antarctica}, journal = {Antarctic Science}, year = {2020}, month = {02/2020}, abstract = {

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.

}, keywords = {LTER-MCM, Dry valleys, hypersalinity, lakes, proglacial, temperature}, doi = {10.1017/S0954102020000036}, url = {https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102020000036}, author = {Lawrence, Jade and Peter T. Doran and Winslow, Luke A. and John C. Priscu} } @article {4154, title = {The Antarctic psychrophiles Chlamydomonas spp. UWO241 and ICE-MDV exhibit differential restructuring of photosystem I in response to iron}, journal = {Photosynthesis Research}, volume = {9}, year = {2019}, month = {02/2019}, abstract = {

Chlamydomonas sp. UWO241 is a psychrophilic alga isolated from the deep photic zone of a perennially ice-covered Antarctic lake (east lobe Lake Bonney, ELB). Past studies have shown that C. sp. UWO241 exhibits constitutive downregulation of photosystem I (PSI) and high rates of PSI-associated cyclic electron flow (CEF). Iron levels in ELB are in the nanomolar range leading us to hypothesize that the unusual PSI phenotype of C. sp. UWO241 could be a response to chronic Fe-deficiency. We studied the impact of Fe availability in C. sp. UWO241, a mesophile, C. reinhardtii SAG11-32c, as well as a psychrophile isolated from the shallow photic zone of ELB, Chlamydomonas sp. ICE-MDV. Under Fe-deficiency, PsaA abundance and levels of photooxidizable P700 (ΔA820/A820) were reduced in both psychrophiles relative to the mesophile. Upon increasing Fe, C. sp. ICE-MDV and C. reinhardtii exhibited restoration of PSI function, while C. sp. UWO241 exhibited only moderate changes in PSI activity and lacked almost all LHCI proteins. Relative to Fe-excess conditions (200 μM Fe2+), C. sp. UWO241 grown in 18 μM Fe2+ exhibited downregulation of light harvesting and photosystem core proteins, as well as upregulation of a bestrophin-like anion channel protein and two CEF-associated proteins (NdsS, PGL1). Key enzymes of starch synthesis and shikimate biosynthesis were also upregulated. We conclude that in response to variable Fe availability, the psychrophile C. sp. UWO241 exhibits physiological plasticity which includes restructuring of the photo-chemical apparatus, increased PSI-associated CEF, and shifts in downstream carbon metabolism toward storage carbon and secondary stress metabolites.

}, keywords = {LTER-MCM, Antarctica, Cyclic electron flow, Iron, Photosystem I, Psychrophile}, issn = {0166-8595}, doi = {10.1007/s11120-019-00621-0}, url = {https://link.springer.com/article/10.1007/s11120-019-00621-0}, author = {Cook, Greg and Teufel, Amber and Kalra, Isha and Li, Wei and Wang, Xin and John C. Priscu and Rachael M. Morgan-Kiss} } @article {4150, title = {Differential incorporation of bacteria, organic matter, and inorganic ions into lake ice during ice formation}, journal = {Journal of Geophysical Research: Biogeosciences}, volume = {124}, year = {2019}, month = {02/2019}, pages = {585 - 600}, abstract = {

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.

}, keywords = {LTER-MCM}, doi = {10.1029/2018JG004825}, url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JG004825}, author = {Santib{\'a}{\~n}ez, Pamela and Alexander B. Michaud and Trista J. Vick-Majors and D{\textquoteright}Andrilli, Juliana and Amy Chiuchiolo and Hand, Kevin P. and John C. Priscu} } @article {4176, title = {Inorganic carbon fixation in ice-covered lakes of the McMurdo Dry Valleys}, journal = {Antarctic Science}, volume = {72}, year = {2019}, month = {04/2019}, abstract = {

Inorganic carbon fixation, usually mediated by photosynthetic microorganisms, is considered to form the base of the food chain in aquatic ecosystems. In high-latitude lakes, lack of sunlight owing to seasonal solar radiation limits the activity of photosynthetic plankton during the polar winter, causing respiration-driven demand for carbon to exceed supply. Here, we show that inorganic carbon fixation in the dark, driven by organisms that gain energy from chemical reactions rather than sunlight (chemolithoautotrophs), provides a significant influx of fixed carbon to two permanently ice-covered lakes (Fryxell and East Bonney). Fryxell, which has higher biomass per unit volume of water, had higher rates of inorganic dark carbon fixation by chemolithoautotrophs than East Bonney (trophogenic zone average 1.0 \µg C l\−1 d\−1\ vs 0.08 \µg C l\−1 d\−1, respectively). This contribution from dark carbon fixation was partly due to the activity of ammonia oxidizers, which are present in both lakes. Despite the potential importance of new carbon input by chemolithoautotrophic activity, both lakes remain net heterotrophic, with respiratory demand for carbon exceeding supply. Dark carbon fixation increased the ratio of new carbon supply to respiratory demand from 0.16 to 0.47 in Fryxell, and from 0.14 to 0.22 in East Bonney.

}, keywords = {LTER-MCM, ammonia oxidation, carbon budget, chemoautotrophy, chemolithoautotrophy}, issn = {0954-1020}, doi = {10.1017/S0954102019000075}, url = {https://www.cambridge.org/core/journals/antarctic-science/article/inorganic-carbon-fixation-in-icecovered-lakes-of-the-mcmurdo-dry-valleys/4B5CA9E91C85B307EFDA69F8D7B5BFD9}, author = {Trista J. Vick-Majors and John C. Priscu} } @article {4151, title = {Prediction of ice-free conditions for a perennially ice-covered Antarctic lake}, journal = {Journal of Geophysical Research: Earth Surface}, volume = {124}, year = {2019}, month = {02/2019}, abstract = {

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.

}, keywords = {LTER-MCM}, doi = {10.1029/2018JF004756}, url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JF004756}, author = {Maciek K. Obryk and Peter T. Doran and John C. Priscu} } @article {4159, title = {BioTIME: A database of biodiversity time series for the Anthropocene}, journal = {Global Ecology and Biogeography}, volume = {27}, year = {2018}, month = {07/2018}, pages = {760-786}, abstract = {

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.

}, keywords = {LTER-MCM, biodiversity, global, spatial, species richness, temporal, turnover}, doi = {10.1111/geb.12729}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/geb.12729}, author = {Dornelas, Maria and Ant{\~a}o, Laura H. and Moyes, Faye and Bates, Amanda E. and Magurran, Anne E. and Adam, Du{\v s}an and Akhmetzhanova, Asem A. and Appeltans, Ward and Arcos, Jos{\'e} Manuel and Arnold, Haley and Ayyappan, Narayanan and Badihi, Gal and Baird, Andrew H. and Barbosa, Miguel and Barreto, Tiago Egydio and B{\"a}ssler, Claus and Bellgrove, Alecia and Belmaker, Jonathan and Benedetti-Cecchi, Lisandro and Bett, Brian J. and Bjorkman, Anne D. and B{\l}a{\.z}ewicz, Magdalena and Blowes, Shane A. and Bloch, Christopher P. and Bonebrake, Timothy C. and Boyd, Susan and Bradford, Matt and Brooks, Andrew J. and Brown, James H. and Bruelheide, Helge and Budy, Phaedra and Carvalho, Fernando and Casta{\~n}eda-Moya, Edward and Chen, Chaolun Allen and Chamblee, John F. and Chase, Tory J. and Siegwart Collier, Laura and Collinge, Sharon K. and Condit, Richard and Cooper, Elisabeth J. and Cornelissen, J. Hans C. and Cotano, Unai and Kyle Crow, Shannan and Damasceno, Gabriella and Davies, Claire H. and Davis, Robert A. and Day, Frank P. and Degraer, Steven and Doherty, Tim S. and Dunn, Timothy E. and Durigan, Giselda and Duffy, J. Emmett and Edelist, Dor and Edgar, Graham J. and Elahi, Robin and Elmendorf, Sarah C. and Enemar, Anders and Ernest, S. K. Morgan and Escribano, Rub{\'e}n and Estiarte, Marc and Evans, Brian S. and Fan, Tung-Yung and Turini Farah, Fabiano and Loureiro Fernandes, Luiz and Farneda, F{\'a}bio Z. and Fidelis, Alessandra and Fitt, Robert and Fosaa, Anna Maria and Daher Correa Franco, Geraldo Antonio and Frank, Grace E. and Fraser, William R. and Garc{\'\i}a, Hernando and Cazzolla Gatti, Roberto and Givan, Or and Gorgone-Barbosa, Elizabeth and Gould, William A. and Gries, Corinna and Grossman, Gary D. and Gutierr{\'e}z, Julio R. and Hale, Stephen and Harmon, Mark E. and Harte, John and Haskins, Gary and Henshaw, Donald L. and Hermanutz, Luise and Hidalgo, Pamela and Higuchi, Pedro and Hoey, Andrew and Van Hoey, Gert and Hofgaard, Annika and Holeck, Kristen and Hollister, Robert D. and Holmes, Richard and Hoogenboom, Mia and Hsieh, Chih-hao and Hubbell, Stephen P. and Huettmann, Falk and Huffard, Christine L. and Hurlbert, Allen H. and Macedo Ivanauskas, Nat{\'a}lia and Jan{\'\i}k, David and Jandt, Ute and Ja{\.z}d{\.z}ewska, Anna and Johannessen, Tore and Johnstone, Jill and Jones, Julia and Jones, Faith A. M. and Kang, Jungwon and Kartawijaya, Tasrif and Keeley, Erin C. and Kelt, Douglas A. and Kinnear, Rebecca and Klanderud, Kari and Knutsen, Halvor and Koenig, Christopher C. and Kortz, Alessandra R. and Kr{\'a}l, Kamil and Kuhnz, Linda A. and Kuo, Chao-Yang and Kushner, David J. and Laguionie-Marchais, Claire and Lancaster, Lesley T. and Min Lee, Cheol and Lefcheck, Jonathan S. and L{\'e}vesque, Esther and Lightfoot, David and Lloret, Francisco and Lloyd, John D. and L{\'o}pez-Baucells, Adri{\`a} and Louzao, Maite and Madin, Joshua S. and Magn{\'u}sson, Borg{\th}{\'o}r and Malamud, Shahar and Matthews, Iain and McFarland, Kent P. and McGill, Brian and Diane M. McKnight and McLarney, William O. and Meador, Jason and Meserve, Peter L. and Metcalfe, Daniel J. and Meyer, Christoph F. J. and Michelsen, Anders and Milchakova, Nataliya and Moens, Tom and Moland, Even and Moore, Jon and Mathias Moreira, Carolina and M{\"u}ller, J{\"o}rg and Murphy, Grace and Myers-Smith, Isla H. and Myster, Randall W. and Naumov, Andrew and Neat, Francis and Nelson, James A. and Paul Nelson, Michael and Newton, Stephen F. and Norden, Natalia and Oliver, Jeffrey C. and Olsen, Esben M. and Onipchenko, Vladimir G. and Pabis, Krzysztof and Pabst, Robert J. and Paquette, Alain and Pardede, Sinta and Paterson, David M. and P{\'e}lissier, Rapha{\"e}l and Pe{\~n}uelas, Josep and P{\'e}rez-Matus, Alejandro and Pizarro, Oscar and Pomati, Francesco and Post, Eric and Prins, Herbert H. T. and John C. Priscu and Provoost, Pieter and Prudic, Kathleen L. and Pulliainen, Erkki and Ramesh, B. R. and Mendivil Ramos, Olivia and Rassweiler, Andrew and Rebelo, Jose Eduardo and Reed, Daniel C. and Reich, Peter B. and Remillard, Suzanne M. and Richardson, Anthony J. and Richardson, J. Paul and van Rijn, Itai and Rocha, Ricardo and Rivera-Monroy, Victor H. and Rixen, Christian and Robinson, Kevin P. and Ribeiro Rodrigues, Ricardo and de Cerqueira Rossa-Feres, Denise and Rudstam, Lars and Ruhl, Henry and Ruz, Catalina S. and Sampaio, Erica M. and Rybicki, Nancy and Rypel, Andrew and Sal, Sofia and Salgado, Beatriz and Santos, Flavio A. M. and Savassi-Coutinho, Ana Paula and Scanga, Sara and Schmidt, Jochen and Schooley, Robert and Setiawan, Fakhrizal and Shao, Kwang-Tsao and Shaver, Gaius R. and Sherman, Sally and Sherry, Thomas W. and Sici{\'n}ski, Jacek and Sievers, Caya and da Silva, Ana Carolina and Rodrigues da Silva, Fernando and Silveira, Fabio L. and Slingsby, Jasper and Smart, Tracey and Snell, Sara J. and Soudzilovskaia, Nadejda A. and Souza, Gabriel B. G. and Maluf Souza, Flaviana and Castro Souza, Vin{\'\i}cius and Stallings, Christopher D. and Stanforth, Rowan and Stanley, Emily H. and Mauro Sterza, Jos{\'e} and Stevens, Maarten and Stuart-Smith, Rick and Rondon Suarez, Yzel and Supp, Sarah} } @article {4061, title = {The physical limnology of a permanently ice-covered and chemically stratified Antarctic lake using high resolution spatial data from an autonomous underwater vehicle}, journal = {Limnology and Oceanography}, volume = {63}, year = {2018}, month = {05/2018}, pages = {1234 - 1252}, abstract = {

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.\ 

}, keywords = {LTER-MCM}, doi = {10.1002/lno.10768}, url = {http://onlinelibrary.wiley.com/wol1/doi/10.1002/lno.10768/full}, author = {Spigel, Robert H. and John C. Priscu and Maciek K. Obryk and Stone, William C. and Peter T. Doran} } @article {4022, title = {Decadal ecosystem response to an anomalous melt season in a polar desert in Antarctica}, journal = {Nature Ecology \& Evolution}, volume = {1}, year = {2017}, month = {09/2017}, pages = {1334-1338}, keywords = {LTER-MCM}, doi = {10.1038/s41559-017-0253-0}, url = {https://www.nature.com/articles/s41559-017-0253-0}, author = {Michael N. Gooseff and John E. Barrett and Byron Adams and Peter T. Doran and Andrew G Fountain and W. Berry Lyons and Diane M. McKnight and John C. Priscu and Eric R. Sokol and Cristina D. Takacs-Vesbach and Martijn L. Vandegehuchte and Ross A. Virginia and Diana H. Wall} } @article {4019, title = {Diversity and Distribution of Freshwater Aerobic Anoxygenic Phototrophic Bacteria across a Wide Latitudinal Gradient}, journal = {Frontiers in Microbiology}, volume = {8}, year = {2017}, month = {02/2017}, abstract = {

Aerobic anoxygenic phototrophs (AAPs) have been shown to exist in numerous marine and brackish environments where they are hypothesized to play important ecological roles. Despite their potential significance, the study of freshwater AAPs is in its infancy and limited to local investigations. Here, we explore the occurrence, diversity and distribution of AAPs in lakes covering a wide latitudinal gradient: Mongolian and German lakes located in temperate regions of Eurasia, tropical Great East African lakes, and polar permanently ice-covered Antarctic lakes. Our results show a widespread distribution of AAPs in lakes with contrasting environmental conditions and confirm that this group is composed of different members of the Alpha- and Betaproteobacteria. While latitude does not seem to strongly influence AAP abundance, clear patterns of community structure and composition along geographic regions were observed as indicated by a strong macro-geographical signal in the taxonomical composition of AAPs. Overall, our results suggest that the distribution patterns of freshwater AAPs are likely driven by a combination of small-scale environmental conditions (specific of each lake and region) and large-scale geographic factors (climatic regions across a latitudinal gradient).

}, keywords = {LTER-MCM}, doi = {10.3389/fmicb.2017.00175}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2017.00175/full}, author = {Ferrera, Isabel and Sarmento, Hugo and John C. Priscu and Amy Chiuchiolo and Jos{\'e} M. Gonz{\'a}lez and Grossart, Hans-Peter} } @article {4111, title = {Early diverging lineages within Cryptomycota and Chytridiomycota dominate the fungal communities in ice-covered lakes of the McMurdo Dry Valleys, Antarctica}, journal = {Scientific Reports}, volume = {7}, year = {2017}, month = {11/2017}, chapter = {15348}, abstract = {

Antarctic ice-covered lakes are exceptional sites for studying the ecology of aquatic fungi under conditions of minimal human disturbance. In this study, we explored the diversity and community composition of fungi in five permanently covered lake basins located in the Taylor and Miers Valleys of Antarctica. Based on analysis of the 18S rRNA sequences, we showed that fungal taxa represented between 0.93\% and 60.32\% of the eukaryotic sequences. Cryptomycota and Chytridiomycota dominated the fungal communities in all lakes; however, members of Ascomycota, Basidiomycota, Zygomycota, and Blastocladiomycota were also present. Of the 1313 fungal OTUs identified, the two most abundant, belonging to LKM11 and Chytridiaceae, comprised 74\% of the sequences. Significant differences in the community structure were determined among lakes, water depths, habitat features (i.e., brackish vs. freshwaters), and nucleic acids (DNA vs. RNA), suggesting niche differentiation. Network analysis suggested the existence of strong relationships among specific fungal phylotypes as well as between fungi and other eukaryotes. This study sheds light on the biology and ecology of basal fungi in aquatic systems. To our knowledge, this is the first report showing the predominance of early diverging lineages of fungi in pristine limnetic ecosystems, particularly of the enigmatic phylum Cryptomycota.

}, keywords = {LTER-MCM}, doi = {10.1038/s41598-017-15598-w}, url = {https://www.nature.com/articles/s41598-017-15598-w}, author = {Rojas-Jimenez, Keilor and Wurzbacher, Christian and Bourne, Elizabeth Charlotte and Amy Chiuchiolo and John C. Priscu and Grossart, Hans-Peter} } @mastersthesis {4092, title = {Long-term and over winter phytoplankton community dynamics in Lake Bonney, Antarctica}, volume = {M.S.}, year = {2017}, month = {2017}, school = {Montana State University}, type = {masters}, address = {Bozeman, MT}, abstract = {

Lake Bonney is a hypersaline permanently ice-covered lake in the Taylor Valley, Antarctica that hosts simplified microbial food-webs. Studied since the 1960s, there are many aspects which are poorly understood. Logistical constraints have prevented sampling during the austral winter, a 4-month period of 24-hour darkness. Our knowledge of how the resident photosynthetic microorganisms respond during this period is limited. With inputs from ephemeral glacial-melt streams the lake level (stage) of Bonney has risen more than 3 m since 2004. With no outflow streams, the only known water loss is via ablation of the permanent ice-cover. A study of the spatial and temporal changes in the phytoplankton community structure during this period of rapid lake level rise is lacking. During the summers (November-January) from 2004-05 to 2014-15 an in situ submersible spectrofluorometer was deployed in Lake Bonney to quantify the chlorophyll-a concentrations (microgram L -1) of four functional groups of microalgae (green algae, brown/mixed algae, cryptophytes, cyanobacteria) using known excitation/emission spectra. During the 2013-14 field season this same instrument was mounted on autonomous cable-crawling profilers deployed in both east and west lobes of Lake Bonney, obtaining the first ever daily profiles of chlorophyll-a concentration at an annual scale. Following a summer of rapid lake level rise (2010-11), an increasing trend in depth integrated chlorophyll-a concentration was observed in Lake Bonney. During the same period, the nutrient poor surface water has become increasingly dominated by green algae. Dramatic shifts were also observed in the phytoplankton communities during the polar night. The highest concentrations of mean chlorophyll-a were measured during the 24-hour darkness. Algal spectral groups containing species capable of a mixotrophic metabolism (brown/mixed and cryptophytes) increased in concentration and relative abundance when photosynthetically active radiation was unavailable. This work provides valuable contributions to our knowledge of long-term and year-round phytoplankton community dynamics in Lake Bonney, and improves our understanding of the metabolic strategies employed by organisms in this high latitude permanently ice-covered lake.

}, keywords = {LTER-MCM}, url = {https://scholarworks.montana.edu/xmlui/handle/1/12803}, author = {Patriarche, Jeffrey D.}, editor = {John C. Priscu} } @article {4103, title = {Niche specialization of bacteria in permanently ice-covered lakes of the McMurdo Dry Valleys, Antarctica}, journal = {Environmental Microbiology}, volume = {19}, year = {2017}, month = {06/2017}, pages = {2258 - 2271}, abstract = {

Perennially ice-covered lakes in the McMurdo Dry Valleys, Antarctica, are chemically stratified with depth and have distinct biological gradients. Despite long-term research on these unique environments, data on the structure of the microbial communities in the water columns of these lakes are scarce. Here, we examined bacterial diversity in five ice-covered Antarctic lakes by 16S rRNA gene-based pyrosequencing. Distinct communities were present in each lake, reflecting the unique biogeochemical characteristics of these environments. Further, certain bacterial lineages were confined exclusively to specific depths within each lake. For example, candidate division WM88 occurred solely at a depth of 15 m in Lake Fryxell, whereas unknown lineages of\ Chlorobi\ were found only at a depth of 18 m in Lake Miers, and two distinct classes of\ Firmicutes\ inhabited East and West Lobe Bonney at depths of 30 m. Redundancy analysis revealed that community variation of bacterioplankton could be explained by the distinct conditions of each lake and depth; in particular, assemblages from layers beneath the chemocline had biogeochemical associations that differed from those in the upper layers. These patterns of community composition may represent bacterial adaptations to the extreme and unique biogeochemical gradients of ice-covered lakes in the McMurdo Dry Valleys.

}, keywords = {LTER-MCM}, doi = {10.1111/emi.2017.19.issue-610.1111/1462-2920.13721}, url = {https://onlinelibrary.wiley.com/doi/pdf/10.1111/1462-2920.13721}, author = {Kwon, Miye and Kim, Mincheol and Cristina D. Takacs-Vesbach and Lee, Jaejin and Hong, Soon Gyu and Kim, Sang Jong and John C. Priscu and Kim, Ok-Sun} } @article {3717, title = {Biogeochemistry and microbial diversity in the marine cavity beneath the McMurdo Ice Shelf, Antarctica}, journal = {Limnology and Oceanography}, volume = {61}, year = {2016}, month = {11/2015}, pages = {572 - 586}, keywords = {LTER-MCM}, doi = {10.1002/lno.v61.210.1002/lno.10234}, url = {http://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.10234}, author = {Trista J. Vick-Majors and Achberger, Amanda and Santib{\'a}{\~n}ez, Pamela and John E. Dore and Hodson, Timothy and Alexander B. Michaud and Brent C. Christner and Jill Ai, Jill. Mikucki and Skidmore, Mark L. and Powell, Ross and Adkins, W. Peyton and Barbante, Carlo and Mitchell, Andrew and Scherer, Reed and John C. Priscu} } @article {3951, title = {Hydrological Controls on Ecosystem Dynamics in Lake Fryxell, Antarctica}, journal = {PLOS ONE}, volume = {11}, year = {2016}, month = {07/2016}, pages = {e0159038}, keywords = {LTER-MCM}, doi = {10.1371/journal.pone.015903810.1371}, url = {http://dx.plos.org/10.1371/journal.pone.0159038}, author = {Herbei, Radu and Rytel, Alexander L. and W. Berry Lyons and Diane M. McKnight and Chris Jaros and Michael N. Gooseff and John C. Priscu}, editor = {Hewitt, Judi} } @article {4102, title = {The Impact of a Large-Scale Climate Event on Antarctic Ecosystem Processes}, journal = {BioScience}, volume = {66}, year = {2016}, month = {10/2016}, pages = {848 - 863}, abstract = {

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.

}, keywords = {LTER-MCM}, issn = {0006-3568}, doi = {10.1093/biosci/biw110}, url = {http://academic.oup.com/bioscience/article-pdf/66/10/848/7510601/biw110.pdf}, author = {Andrew G Fountain and Saba, Grace and Byron Adams and Peter T. Doran and Fraser, William and Michael N. Gooseff and Maciek K. Obryk and John C. Priscu and Sharon E. Stammerjohn and Ross A. Virginia} } @article {4017, title = {Microbial Community Dynamics in Two Polar Extremes: The Lakes of the McMurdo Dry Valleys and the West Antarctic Peninsula Marine Ecosystem}, journal = {BioScience}, volume = {66}, year = {2016}, month = {Jan-10-2016}, pages = {829 - 847}, keywords = {LTER-MCM}, issn = {0006-3568}, doi = {10.1093/biosci/biw103}, url = {https://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-Extremes}, author = {Bowman, Jeff S. and Trista J. Vick-Majors and Rachael M. Morgan-Kiss and Cristina D. Takacs-Vesbach and Hugh W. Ducklow and John C. Priscu} } @article {4013, title = {Microbial Community Structure of Subglacial Lake Whillans, West Antarctica}, journal = {Frontiers in Microbiology}, volume = {7}, year = {2016}, month = {Oct-09-2017}, keywords = {LTER-MCM}, doi = {10.3389/fmicb.2016.01457}, url = {http://journal.frontiersin.org/Article/10.3389/fmicb.2016.01457/abstract}, author = {Achberger, Amanda and Brent C. Christner and Alexander B. Michaud and John C. Priscu and Skidmore, Mark L. and Trista J. Vick-Majors} } @phdthesis {4090, title = {Microbially mediated biogeochemical cycles in polar ice covered lakes}, volume = {Ph.D.}, year = {2016}, school = {Montana State University}, type = {doctoral}, address = {Bozeman, MT}, abstract = {

Lakes are important sites for globally-relevant biogeochemical cycles mediated by microorganisms. In the Arctic, seasonally ice covered thermokarst lakes are a large component in Earth\&$\#$39;s carbon cycle due to their methane emissions from organic carbon degradation. In the Antarctic, over 400 unexplored lakes exist beneath the Antarctic ice sheet with unknown biogeochemical contributions to the Earth system. This dissertation seeks to investigate the biogeochemical role of microorganisms in the lake habitat and how they interact with the seasonal and permanent ice covers of lakes in polar environments. Microbiologically clean hot water drilling was used to access a subglacial lake beneath Antarctica\&$\#$39;s ice to collect, for the first time, intact sediment and water samples. Laboratory experiments on Arctic and Antarctic, seasonally and perennially, respectively, ice covered lakes were used to investigate the impact of lake ice freezing regimes on microorganisms. My results show that subglacial lake sediments beneath the West Antarctic Ice Sheet contain solute ratios that suggest relict marine sediments were deposited during previous interglacial periods. Microbial activity overprints the marine geochemical signature to produce fluxes of ions into the Subglacial Lake Whillans water column, which ultimately drains to the Southern Ocean. Microbial activity in Subglacial Lake Whillans is partially fueled by biologically-formed methane diffusing from below our deepest collected (~38 cm) subglacial sediment samples. The ice above Subglacial Lake Whillans appears to be an important source of molecular oxygen for microorganisms to drive oxidative physiologies. My experimental evidence shows microorganisms incorporate into lake ice cover to, potentially, avoid increasing stressors from progressive lake ice freezing. Taken together, the results from this dissertation reinforce the hypothesis that subglacial environments beneath the Antarctic ice sheet are habitats for life. Further, the microorganisms in subglacial lakes participate in globally-relevant biogeochemical cycles. Here, I extend the extent of the biosphere and show sediments at the base of ice sheets are an active component of the Earth system.

}, keywords = {LTER-MCM}, url = {https://scholarworks.montana.edu/xmlui/handle/1/13793}, author = {Alexander B. Michaud}, editor = {John C. Priscu} } @article {3919, title = {Modeling the thickness of perennial ice covers on stratified lakes of the Taylor Valley, Antarctica}, journal = {Journal of Glaciology}, year = {2016}, month = {06/2016}, pages = {1 - 10}, chapter = {1}, abstract = {
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.

}, keywords = {LTER-MCM}, issn = {0022-1430}, doi = {10.1017/jog.2016.69}, url = {http://www.journals.cambridge.org/abstract_S0022143016000691}, author = {Maciek K. Obryk and Peter T. Doran and J. A. Hicks and Christopher P. McKay and John C. Priscu} } @article {1061, title = {Photoadaptation to the polar night by phytoplankton in a permanently ice-covered Antarctic lake}, journal = {Limnology and Oceanography}, volume = {61}, year = {2016}, month = {05/2015}, abstract = {

Photosynthetic microorganisms are a primary source of new organic carbon production in polar ecosystems. Despite their importance, relatively little is known about how they adapt to the bimodal solar cycles that exist at high latitudes. To understand how phytoplankton adapt to the extreme seasonal change in photoperiod, we transplanted cultures of a well-studied laboratory model for photosynthetic cold adaptation,\ Chlamydomonas raudensis\ UWO241, back to the water column of Lake Bonney (McMurdo Dry Valleys, Antarctica) at the depth from which it was originally cultured. The organism was suspended at this depth in dialysis tubing to allow the microalga to respond to the in situ light, temperature and dissolved ions. We then integrated in situ biological and chemical measurements with environmental molecular analyses and compared the responses of transplanted\ C. raudensis\ cultures with the natural phytoplankton community over the 6-week transition from Antarctic summer (24-h daylight) to polar night (24-h darkness). As solar radiation declined, natural communities exhibited a cessation of inorganic carbon fixation which was accompanied by a downregulation of expression of genes encoding for essential carbon fixation and photochemistry proteins. Transplanted\ C. raudensis\ cultures matched natural community trends in the regulation of photochemistry and carbon fixation gene expression, and shifted photochemical function to a shade adapted state in response to the polar night transition. We present a conceptual model for seasonal shifts in microbial community energy and carbon acquisition which integrates past cultivation-based studies in this model photopsychrophile with a body of recent work on adaptation of natural populations to polar night.

}, keywords = {LTER-MCM}, doi = {10.1002/lno.10107}, url = {https://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lno.10107}, author = {Rachael M. Morgan-Kiss and Michael P. Lizotte and Weidong Kong and John C. Priscu} } @mastersthesis {4088, title = {Physiological characteristics of fungi associated with Antarctic environments}, volume = {M.S.}, year = {2016}, school = {Montana State University}, type = {masters}, address = {Bozeman, MT}, abstract = {

The permanent ice covers on the lakes of Antarctica\&$\#$39;s McMurdo Dry Valleys region harbor a diverse group of phototrophic and heterotrophic microorganisms that metabolize during the short summer months when solar radiation produces melt inclusions within the ice and provides energy to drive photosynthesis. Laboratory cultures of fungi were obtained from ice cores taken from Lakes Bonney (east lobe) and Chad, and sediments collected from Subglacial Lake Whillans (West Antarctica). Using molecular techniques, the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA) was sequenced to identify fungal types and to determine whether they may be unique to this region. Four axenic fungal cultures, Tetracladium ellipsoideum, Lecythophora hoffmannii, Mucor sp., and an unidentified Ascomycota were successfully isolated. These isolates are closely related to organisms that have been previously reported in Antarctica and other cold habitats. The isolates were tested for growth characteristics under various temperature and nutrient regimes. Temperature response experiments revealed that all the isolated fungi were psychrotolerant and growth rates were greatest at 25\°C. Of major significance in evaluating the potential of Antarctic fungi as a bioresource is their ability to produce bioactive compounds. Two out of four isolated organisms exhibited antimicrobial activity against several plant pathogens. The metabolic potential and preferred substrate utilization was examined by exposing fungal isolates to a variety of substrates in a 96 well \"Biolog\" plate. A strong correlation was found among substrate utilization, isolates, temperature and the different carbon substrates. This experiment revealed that the isolated fungi have preferences for different labile carbon substrates at 4\°C and 24\°C which may imply different physiologies at different times of year in the lake ice-covers. Results from my studies will help understand the role of fungi in lake ice and subglacial lake sediment ecosystems, and the physiology of fungi living in cold environments.

}, keywords = {LTER-MCM}, url = {https://scholarworks.montana.edu/xmlui/handle/1/9835}, author = {Kudalkar, Priyanka S. and John C. Priscu} } @article {4033, title = {Physiological Ecology of Microorganisms in Subglacial Lake Whillans}, journal = {Frontiers in Microbiology}, volume = {7}, year = {2016}, month = {Mar-10-2018}, keywords = {LTER-MCM}, doi = {10.3389/fmicb.2016.01705}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2016.01705/fullhttp://journal.frontiersin.org/article/10.3389/fmicb.2016.01705/full}, author = {Trista J. Vick-Majors and Mitchell, Andrew and Achberger, Amanda and Brent C. Christner and John E. Dore and Alexander B. Michaud and Jill A. Mikucki and Purcell, Alicia M. and Skidmore, Mark L. and John C. Priscu} } @article {4030, title = {Responses of Antarctic Marine and Freshwater Ecosystems to Changing Ice Conditions}, journal = {BioScience}, volume = {66}, year = {2016}, month = {Jan-10-2016}, pages = {864 - 879}, keywords = {LTER-MCM}, issn = {0006-3568}, doi = {10.1093/biosci/biw109}, url = {https://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-Freshwater}, author = {Maciek K. Obryk and Peter T. Doran and Friedlaender, Ari S. and Michael N. Gooseff and Li, Wei and Rachael M. Morgan-Kiss and John C. Priscu and Schofield, Oscar and Sharon E. Stammerjohn and Steinberg, Deborah K. and Hugh W. Ducklow} } @article {4169, title = {Unraveling ecosystem responses to climate change on the Antarctic continent through Long-Term Ecological Research}, journal = {BioScience}, volume = {66}, year = {2016}, month = {10/2016}, pages = {799 - 800}, keywords = {LTER-MCM}, issn = {0006-3568}, doi = {10.1093/biosci/biw131}, url = {https://academic.oup.com/bioscience/article/66/10/799/2236166}, author = {John C. Priscu} } @article {3214, title = {Autonomous Year-Round Sampling and Sensing to Explore the Physical and Biological Habitability of Permanently Ice-Covered Antarctic Lakes}, journal = {Marine Technology Society Journal}, volume = {48}, year = {2014}, month = {Jan-09-2014}, pages = {8 - 17}, abstract = {

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.

}, keywords = {LTER-MCM}, issn = {00253324}, doi = {10.4031/MTSJ.48.5.6}, url = {http://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/art00002}, author = {Winslow, Luke A. and Hilary A. Dugan and Heather N. Buelow and Cronin, Kyle D. and John C. Priscu and Cristina D. Takacs-Vesbach and Peter T. Doran} } @article {1056, title = {Ciliate diversity, community structure and novel taxa in lakes of the McMurdo Dry Valleys, Antarctica}, journal = {Biological Bulleting}, volume = {227}, year = {2014}, month = {10/2014}, pages = {175-190}, chapter = {175}, abstract = {We report an in-depth survey of next-generation DNA sequencing of ciliate diversity and community structure in two permanently ice-covered McMurdo Dry Valley lakes during the austral summer and autumn (November 2007 and March 2008). We tested hypotheses on the relationship between species richness and environmental conditions including environmental extremes, nutrient status, and day length. On the basis of the unique environment that exists in these high-latitude lakes, we expected that novel taxa would be present. Alpha diversity analyses showed that extreme conditions-that is, high salinity, low oxygen, and extreme changes in day length-did not impact ciliate richness; however, ciliate richness was 30\% higher in samples with higher dissolved organic matter. Beta diversity analyses revealed that ciliate communities clustered by dissolved oxygen, depth, and salinity, but not by season (i.e., day length). The permutational analysis of variance test indicated that depth, dissolved oxygen, and salinity had significant influences on the ciliate community for the abundance matrices of resampled data, while lake and season were not significant. This result suggests that the vertical trends in dissolved oxygen concentration and salinity may play a critical role in structuring ciliate communities. A PCR-based strategy capitalizing on divergent eukaryotic V9 hypervariable region ribosomal RNA gene targets unveiled two new genera in these lakes. A novel taxon belonging to an unknown class most closely related to Cryptocaryon irritans was also inferred from separate gene phylogenies.}, keywords = {LTER-MCM}, author = {Yuan, Xu and Trista J. Vick-Majors and Rachael M. Morgan-Kiss and John C. Priscu and Linda A. Amaral-Zettler} } @article {1085, title = {Modular community structure suggests metabolic plasticity during the transition to polar night in ice-covered Antarctic lakes}, journal = {The ISME Journal}, year = {2014}, month = {10/2013}, keywords = {LTER-MCM}, doi = {10.1038/ismej.2013.190}, url = {http://www.nature.com/ismej/journal/vaop/ncurrent/full/ismej2013190a.html}, author = {Trista J. Vick-Majors and John C. Priscu and Linda A. Amaral-Zettler} } @article {3212, title = {The 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 column}, journal = {Journal of Geophysical Research: Biogeosciences}, volume = {119}, year = {2014}, month = {09/2014}, pages = {1879 - 1891}, chapter = {1879}, abstract = {

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.

}, keywords = {LTER-MCM}, doi = {10.1002/2014JG002672}, url = {http://doi.wiley.com/10.1002/2014JG002672}, author = {Maciek K. Obryk and Peter T. Doran and John C. Priscu} } @article {3525, title = {Polar and alpine microbiology in a changing world}, journal = {FEMS Microbiology Ecology}, volume = {89}, year = {2014}, month = {08/2014}, pages = {209 - 210}, chapter = {209}, keywords = {LTER-MCM}, doi = {10.1111/fem.2014.89.issue-210.1111/1574-6941.12371}, url = {http://onlinelibrary.wiley.com/doi/10.1111/1574-6941.12371/abstract}, author = {John C. Priscu and Johanna Laybourn-Parry and H{\"a}ggblom, Max} } @article {1101, title = {Aeolian flux of biotic and abiotic material in Taylor Valley, Antarctica}, journal = {Geomorphology}, volume = {155-156}, year = {2012}, month = {6/2012}, pages = {102 - 111}, keywords = {LTER-MCM}, doi = {10.1016/j.geomorph.2011.12.009}, url = {http://www.sciencedirect.com/science/article/pii/S0169555X11006222}, author = {Marie {\v S}aback{\'a} and John C. Priscu and Hassan J. Basagic and Andrew G Fountain and Diana H. Wall and Ross A. Virginia and Mark C. Greenwood} } @article {3527, title = {Bacterioplankton productivity in lakes of the Taylor Valley, Antarctica, during the polar night transition}, journal = {Aquatic Microbial Ecology}, volume = {68}, year = {2012}, month = {12/2013}, pages = {77 - 90}, abstract = {

Research on the lakes of the McMurdo Dry Valleys, Antarctica, is typically conducted during the period of 24 h sunlight (October to January) when logistical support is readily available. As part of the International Polar Year initiative, we obtained logistical support to study microbial dynamics in the permanently ice-covered lakes of the Taylor Valley during the transition from 24 h of sunlight to the complete darkness of the polar night (mid-April). Our study focused on the perennially ice-covered lakes Fryxell (FRX), East Lobe Bonney (ELB), and West Lobe Bonney (WLB), all of which are chemically stratified and have food webs dominated by microorganisms. Depth-integrated bacterioplankton productivity (BP; leucine incorporation [Leu] and thymidine incorporation [TdR]) in the lakes ranged from 1.2 to 3.4 mg C m\−2\ d\−1. Overall, summer was characterized by relatively high rates of BP and photoautotrophic primary productivity. Rapid decreases in photosynthetically active radiation marked a subsequent transition period, which was characterized by variable cell counts and decreasing Leu:TdR ratios (ratios \>1 signify a physiological shift from growth to maintenance mode). Finally, cell counts decreased and Leu:TdR increased by as much as 280\% during the fall, revealing a distinct change in the physiological state of the bacterioplankton as light-mediated primary productivity ceased. Our data reveal that the shift in physiological state may result from a switch from contemporary phytoplankton-excreted carbon to other sources of dissolved organic carbon, which can support the bacterioplankton populations through the winter.

}, keywords = {LTER-MCM}, issn = {0948-3055}, doi = {10.3354/ame01604}, url = {http://www.int-res.com/abstracts/ame/v68/n1/p77-90}, author = {Trista J. Vick-Majors and John C. Priscu} } @article {1106, title = {Chemical analysis of ice vein microenvironments: II. Analysis of glacial samples from Greenland and Antarctica}, journal = {Journal of Glaciology}, volume = {58}, year = {2012}, month = {12/2012}, pages = {1109 - 1118}, keywords = {LTER-MCM}, doi = {10.3189/2012JoG12J112}, url = {http://www.montana.edu/priscu/DOCS/Publications/BarlettaEtAl2012IceVein.pdf}, author = {Barletta, Robert E. and John C. Priscu and Mader, Heidy M. and Jones, Warren L. and Roe, Christopher H.} } @article {1109, title = {Cyanobacterial diversity across landscape units in a polar desert: Taylor Valley, Antarctica}, journal = {FEMS Microbiology Ecology}, volume = {82}, year = {2012}, month = {11/2012}, pages = {268 - 278}, keywords = {LTER-MCM}, doi = {10.1111/j.1574-6941.2012.01297.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1574-6941.2012.01297.x/full}, author = {Alexander B. Michaud and Marie {\v S}aback{\'a} and John C. Priscu} } @article {1118, title = {Diversity and Expression of RubisCO Genes in a Perennially Ice-Covered Antarctic Lake during the Polar Night Transition}, journal = {Applied and Environmental Microbiology}, volume = {78}, year = {2012}, month = {04/2012}, pages = {4358-4366}, keywords = {LTER-MCM}, url = {http://aem.asm.org/content/78/12/4358.short}, author = {Weidong Kong and David C. Ream and John C. Priscu and Rachael M. Morgan-Kiss} } @article {1110, title = {Evidence of form II RubisCO ( cbbM) in a perennially ice-covered Antarctic lake}, journal = {FEMS Microbiology Ecology}, volume = {82}, year = {2012}, month = {11/2012}, pages = {491 - 500}, keywords = {LTER-MCM}, doi = {10.1111/j.1574-6941.2012.01431.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1574-6941.2012.01431.x/full}, author = {Weidong Kong and Jenna M. Dolhi and Amy Chiuchiolo and John C. Priscu and Rachael M. Morgan-Kiss} } @article {1113, title = {Microbial dynamics and flagellate grazing during transition to winter in Lakes Hoare and Bonney, Antarctica}, journal = {FEMS Microbiology Ecology}, volume = {82}, year = {2012}, month = {11/2012}, pages = {449 - 458}, keywords = {LTER-MCM}, doi = {10.1111/j.1574-6941.2012.01423.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1574-6941.2012.01423.x/full}, author = {Jill Thurman and Jacqueline Parry and Philip J. Hill and John C. Priscu and Trista J. Vick-Majors and Amy Chiuchiolo and Johanna Laybourn-Parry} } @article {3528, title = {Microbial life at -13 ~C in the brine of an ice-sealed Antarctic lake}, journal = {Proceedings of the National Academy of Sciences}, volume = {109}, year = {2012}, month = {12/2012}, pages = {20626 - 20631}, keywords = {LTER-MCM}, issn = {0027-8424}, doi = {10.1073/pnas.1208607109}, url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1208607109}, author = {A. E. Murray and Kenig, Fabien and Christian H. Fritsen and Christopher P. McKay and Kaelin M. Cawley and R. L. Edwards and Kuhn, Emanuele and Diane M. McKnight and Nathaniel E Ostrom and Vivian Peng and Adrian Ponce and John C. Priscu and Samarkin, Vladimir A. and Ashley T Townsend and Protima Wagh and Seth A Young and Pung To Yung and Peter T. Doran} } @article {1107, title = {Perchlorate and chlorate biogeochemistry in ice-covered lakes of the McMurdo Dry Valleys, Antarctica}, journal = {Geochimica et Cosmochimica Acta}, volume = {98}, year = {2012}, month = {12/2012}, pages = {19 - 30}, keywords = {LTER-MCM}, doi = {10.1016/j.gca.2012.09.014}, url = {http://www.sciencedirect.com/science/article/pii/S001670371200511X}, author = {W. Andrew Jackson and Alfonso F. Davila and Nubia Estrada and W. Berry Lyons and John D. Coates and John C. Priscu} } @book {1123, title = {Poisson Reconstruction of Extreme Submersed Environments: The ENDURANCE Exploration of an Under-Ice Antarctic Lake}, series = {Advances in Visual Computing. ISVC 2012. Lecture Notes in Computer Science.}, volume = {7431}, year = {2012}, pages = {394 - 403}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, address = {Berlin, Heidelberg}, abstract = {

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.

}, keywords = {LTER-MCM}, isbn = {978-3-642-33179-4}, doi = {10.1007/978-3-642-33179-4_38}, url = {http://www.springerlink.com/content/hg97w43588229087/}, author = {Alessandro Febretti and Kristof Richmond and Gulati, Shilpa and Flesher, Christopher and Hogan, Bartholomew P. and Andrew Johnson and Stone, William C. and John C. Priscu and Peter T. Doran}, editor = {Bebis, George and Boyle, Richard and Parvin, Bahram and Koracin, Darko and Fowlkes, Charless and Wang, Sen and Choi, Min-Hyung and Mantler, Stephan and Schulze, J{\"u}rgen and Acevedo, Daniel and Mueller, Klaus and Papka, Michael} } @phdthesis {4193, title = {Wind as an ecological factor in the McMurdo Dry Valleys, Antarctica}, volume = {Ph.D.}, year = {2012}, month = {2012}, pages = {201}, school = {Montana State University}, type = {doctoral}, address = {Bozeman, MT}, abstract = {

The aim of this work was to investigate the role of wind on the ecology of the McMurdo Dry Valleys in Antarctica (MDV), one of the coldest and driest deserts on Earth. The MDV landscape consists of a mosaic of permanently ice-covered lakes, ephemeral streams, exposed soils, and glaciers, all of which contain habitats dominated by microorganisms. Data on wind-driven flux of sediments and associated organic matter were collected using passive aeolian traps and dynamic mass erosion particle counters to investigate the timing, direction and magnitude of aeolian sediment transport. Combination of genomic techniques and phenotypical fingerprinting (pigment analysis) was used to examine microbial diversity over a wide variety of wind-eroded habitats across the MDV landscape to elucidate the role of wind dispersal on the contemporary distribution of microorganisms across the MDVs. Sediment entrainment occurs predominantly within 20 cm of the ground surface and has character of saltation bursts that occupy \<3\% of the total time within a year. The high-energy winter f{\"o}hn winds uplift sediments in the upper parts of the MDVs and transport them down-valley where they are deposited onto the surface of perennially ice-covered lakes and surrounding soils. The sediment that enters the water column of the lakes does not provide a significant source of organic carbon for bacterioplankton communities compared to the in situ production by phytoplankton but can be a source of new microbial propagules. The aeolian material is low in organic matter (\<1\% dw) but is composed of a relatively large numbers of cyanobacterial taxa (~20 OTUs) that can be found in all other MDV habitats. In conclusion, wind distributes microorganisms across the MDV landscape but local environment selects for specific taxa. Predicted climate warming will increase the importance of wind transport, which will affect nutrient cycling and connectivity among MDV ecosystem components.

}, keywords = {LTER-MCM}, url = {https://scholarworks.montana.edu/xmlui/handle/1/2171}, author = {Marie {\v S}aback{\'a} and John C. Priscu} } @book {1142, title = {Frontiers in Understanding Climate Change and Polar Ecosystems}, series = {Committee on Frontiers in Understanding Climate Change and Polar Ecosystems Polar Research Board Division of Earth and Life Studies}, year = {2011}, publisher = {The National Academies Press}, organization = {The National Academies Press}, keywords = {LTER-MCM}, isbn = {0-309-21087-9}, author = {Grebmeier, J. and John C. Priscu} } @article {1125, title = {Protist diversity in a permanently ice-covered Antarctic Lake during the polar night transition}, journal = {The ISME Journal}, volume = {5}, year = {2011}, month = {9/2011}, pages = {1559 - 1564}, keywords = {LTER-MCM}, doi = {10.1038/ismej.2011.23}, url = {http://www.nature.com/ismej/journal/v5/n9/abs/ismej201123a.html}, author = {Scott Bielewicz and Elanor R. Bell and Weidong Kong and Iddo Friedberg and John C. Priscu and Rachael M. Morgan-Kiss} } @article {1148, title = {Abiotic nitrous oxide emission from the hypersaline Don Juan Pond in Antarctica}, journal = {Nature Geoscience}, volume = {3}, year = {2010}, month = {5/2010}, pages = {341 - 344}, keywords = {LTER-MCM}, doi = {10.1038/ngeo847}, url = {http://www.nature.com/ngeo/journal/v3/n5/full/ngeo847.html}, author = {Samarkin, Vladimir A. and Madigan, Michael T. and Bowles, Marshall W. and Karen L. Casciotti and John C. Priscu and Christopher P. McKay and Joye, Samantha B.} } @mastersthesis {4194, title = {Bacterioplakton dynamics in stratified lakes of the Taylor Valley, Antarctica during the transition to polar night}, volume = {M.S.}, year = {2010}, month = {2010}, pages = {83}, school = {Montana State University}, type = {masters}, address = {Bozeman, MT}, abstract = {

Limnological research on the lakes of the McMurdo Dry Valleys (MCM), Antarctica, is typically carried out during the austral spring-summer (October January) when logistical support is readily available; the current study marks the first sampling effort during the summer-fall transition (January-April). Sampling during the darkness of winter is logistically difficult and expensive, and my study is an important step towards understanding the year-round ecology of the dry valley lakes. Bacterial productivity, measured as protein synthesis and DNA replication, and bacterial cell numbers were measured 10-12 times between October 2007 and April 2008 in Lakes Fryxell (FRX) and the east and west lobes of Lake Bonney (ELB and WLB). Lake Fryxell was the most productive (bacterial) lake on average by an order of magnitude (average = 1.24 mg C m -\²d -\¹; range = 0.00 to 3.29 mg C m -\²d -\¹), and also contained the greatest bacterial biomass (~10 $^{6}$ cells ml -\¹) by 1 to 3 orders of magnitude. If bacterial production were directly linked to organic carbon supplied by photosynthetic primary production, a decrease in bacterial production would be expected during the sunset; however, no statistically significant change in bacterial production (a=0.05) was observed during the summer-fall transition. A distinct decoupling of bacterial protein production and DNA replication was detected in FRX and ELB of the lakes as the season progressed, and was present in WLB throughout the season, indicating either a shift towards a lower growth-rate in response to decreasing light or nutrient supply, or a mechanism for dealing with the perennially low temperatures, low light, and nutrient poor conditions in the lakes. Overall, it appears that bacterial communities remain active during the darkness of winter, when the lakes enter a period of \"net heterotrophy\", which cannot be sustained unless the carbon balance of the TV lakes is reset by climatic events.

}, keywords = {LTER-MCM}, url = {https://scholarworks.montana.edu/xmlui/handle/1/2477}, author = {Trista J. Vick-Majors and John C. Priscu} } @article {1150, title = {Biogeochemical weathering under ice: Size matters}, journal = {Global Biogeochemical Cycles}, volume = {24}, year = {2010}, month = {2010}, keywords = {LTER-MCM}, doi = {10.1029/2009GB003688}, author = {Wadham, J. L. and Martyn Tranter and Skidmore, M and Hodson, A. J. and John C. Priscu and W. Berry Lyons and Sharp, M. and Wynn, P. and Margaret S. Jackson} } @article {1157, title = {Design and deployment of a four-degrees-of-freedom hovering autonomous underwater vehicle for sub-ice exploration and mapping}, journal = {Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment}, volume = {224}, year = {2010}, month = {11/2010}, pages = {341 - 361}, keywords = {LTER-MCM}, doi = {10.1243/14750902JEME214}, author = {Stone, W and Bartholomew P Hogan and Flesher, C and Gulati, S and Kristof Richmond and Murarka, A and Kuhlman, G and Idharan, M and Siegel, V and Price, R M and Peter T. Doran and John C. Priscu} } @inbook {1171, title = {Factors promoting microbial diversity in the McMurdo Dry Valleys}, booktitle = {Life in Antarctic Deserts and other Cold Dry Environments: Astrobiological Analogues}, series = {Cambridge Astrobiology}, volume = {5}, year = {2010}, pages = {221-257}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, keywords = {LTER-MCM}, isbn = {9780521889193}, doi = {10.1017/CBO9780511712258.008}, url = {http://ebooks.cambridge.org/chapter.jsf?bid=CBO9780511712258\&cid=CBO9780511712258A015}, author = {Cristina D. Takacs-Vesbach and Lydia H. Zeglin and Michael N. Gooseff and John E. Barrett and John C. Priscu} } @article {1174, title = {Physiochemical properties influencing biomass abundance and primary production in Lake Hoare, Antarctica}, journal = {Ecological Modelling}, year = {2010}, keywords = {LTER-MCM}, doi = {LTER}, author = {Herbei, Radu and W. Berry Lyons and Johanna Laybourn-Parry and Christopher B. Gardner and John C. Priscu and Diane M. McKnight} } @article {1176, title = {Sediment Melt Dynamics in Permanent Antarctic Lake Ice}, journal = {Arctic, Antarctic, and Alpine Research}, volume = {42}, year = {2010}, pages = {57-66}, keywords = {LTER-MCM}, doi = {10.1657/1938-4246-42.1.57}, url = {http://mcmlter.lternet.edu/reports/lakes/JepsenEtAl2010SedimentMeltMigration.pdf}, author = {Steven M. Jepsen and Edward E. Adams and John C. Priscu} } @article {1154, title = {Spatial variations in the geochemistry of glacial meltwater streams in the Taylor Valley, Antarctica}, journal = {Antarctic Science}, volume = {22}, year = {2010}, month = {12/2010}, pages = {662 - 672}, keywords = {LTER-MCM}, doi = {10.1017/S0954102010000702}, url = {http://www.montana.edu/lkbonney/DOCS/Publications/WelchEtAl2010Geochemistry.pdf}, author = {Kathleen A. Welch and W. Berry Lyons and Whisner, Carla and Christopher B. Gardner and Michael N. Gooseff and Diane M. McKnight and John C. Priscu} } @article {1159, title = {Viable microbes in ice: application of molecular assays to McMurdo Dry Valley lake ice communities}, journal = {Antarctic Science}, volume = {22}, year = {2010}, month = {10/2010}, pages = {470 - 476}, abstract = {

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.

}, keywords = {LTER-MCM}, doi = {10.1017/S0954102010000404}, url = {http://journals.cambridge.org/action/displayAbstract?fromPage=online\&aid=7909836\&fileId=S0954102010000404}, author = {Markus Dieser and Nocker, Andreas and John C. Priscu and Christine M. Foreman} } @article {1185, title = {Composition and Biodegradation of a Synthetic Oil Spilled on the Perennial Ice Cover of Lake Fryxell, Antarctica}, journal = {Environmental Science \& Technology}, volume = {43}, year = {2009}, pages = {2708-2713}, keywords = {LTER-MCM}, doi = {LTER}, author = {Jaraula, C and Kenig, Fabien and Peter T. Doran and John C. Priscu and Kathleen A. Welch} } @article {1184, title = {A Contemporary Microbially Maintained Subglacial Ferrous "Ocean"}, journal = {Science}, volume = {324}, year = {2009}, month = {04/2009}, pages = {397-400}, type = {Journal}, abstract = {

An active microbial assemblage cycles sulfur in a sulfate-rich, ancient marine brine beneath Taylor Glacier, an outlet glacier of the East Antarctic Ice Sheet, with Fe(III) serving as the terminal electron acceptor. Isotopic measurements of sulfate, water, carbonate, and ferrous iron and functional gene analyses of adenosine 5\′-phosphosulfate reductase imply that a microbial consortium facilitates a catalytic sulfur cycle. These metabolic pathways result from a limited organic carbon supply because of the absence of contemporary photosynthesis, yielding a subglacial ferrous brine that is anoxic but not sulfidic. Coupled biogeochemical processes below the glacier enable subglacial microbes to grow in extended isolation, demonstrating how analogous organic-starved systems, such as Neoproterozoic oceans, accumulated Fe(II) despite the presence of an active sulfur cycle.

}, keywords = {LTER-MCM, Biggie}, doi = {10.1126/science.1167350}, url = {http://www.sciencemag.org/content/324/5925/397.short}, author = {Jill A. Mikucki and Pearson, A and Johnston, D and Turchyn, A and Farquhar, J and Schrag, D and Anbar, A and John C. Priscu and Lee, P} } @inbook {1188, title = {Lakes of Antarctica}, booktitle = {Encyclopedia of Inland Waters volume 2}, year = {2009}, pages = {555-566}, publisher = {Elsevier Press}, organization = {Elsevier Press}, address = {Oxford}, keywords = {LTER-MCM}, doi = {LTER}, author = {John C. Priscu and Christine M. Foreman}, editor = {G.E. Likens} } @inbook {1206, title = {Antarctic subglacial water: origin, evolution, and ecology}, booktitle = {Polar Lakes and Rivers: Limnology of Arctic and Antarctic Aquatic Ecosystems}, year = {2008}, publisher = {Oxford University Press}, organization = {Oxford University Press}, address = {Oxford}, keywords = {LTER-MCM}, author = {John C. Priscu and Tulaczyk, S and Studinger, M and Kenicutt, M and Brent C. Christner and Christine M. Foreman} } @inbook {1207, title = {Bacteria in Subglacial Environments}, booktitle = {Psychrophiles: from biodiversity to biotechnology}, year = {2008}, pages = {51-71}, publisher = {Springer Verlag}, organization = {Springer Verlag}, address = {New York}, keywords = {LTER-MCM}, author = {Brent C. Christner and Skidmore, M and John C. Priscu and Martyn Tranter and Christine M. Foreman} } @article {1208, title = {Bacteriophage in polar inland waters}, journal = {Extremophiles}, volume = {12}, year = {2008}, pages = {167-175}, keywords = {LTER-MCM}, doi = {LTER}, url = {/reports/lakes/SawstromEtAl2008Bacteriophage.pdf}, author = {Sawstrom, C and John T. Lisle and Alexandre M. Anesio and John C. Priscu and Johanna Laybourn-Parry} } @inbook {1213, title = {Glacial ecosystems}, booktitle = {Ecological Monographs}, volume = {78}, year = {2008}, pages = {41-67}, edition = {1}, abstract = {
There is now compelling evidence that microbially mediated reactions impart a significant effect upon the dynamics, composition, and abundance of nutrients in glacial melt water. Consequently, we must now consider ice masses as ecosystem habitats in their own right and address their diversity, functional potential, and activity as part of alpine and polar environments. Although such research is already underway, its fragmentary nature provides little basis for developing modern concepts of glacier ecology. This paper therefore provides a much-needed framework for development by reviewing the physical, biogeochemical, and microbiological characteristics of microbial habitats that have been identified within glaciers and ice sheets. Two key glacial ecosystems emerge, one inhabiting the glacier surface (the supraglacial ecosystem) and one at the ice-bed interface (the subglacial ecosystem). The supraglacial ecosystem is characterized by a diverse consortium of microbes (usually bacteria, algae, phytoflagellates, fungi, viruses and occasional rotifers, tardigrades, and diatoms) within the snowpack, supraglacial streams, and melt pools (cryoconite holes). The subglacial system is dominated by aerobic/anaerobic bacteria and most probably viruses in basal ice/till mixtures and subglacial lakes. A third, so-called englacial ecosystem is also described, but it is demonstrated that conditions within glacier ice are sufficient to make metabolic activity and its impact upon nutrient dynamics negligible at the glacier scale.
Consideration of the surface and internal heat balances of the glacier show that all glacial ecosystems are sensitive to climate change, although at different timescales. Thus, while rapid, melt-driven habitat changes lead to melt-out, resuscitation, and redistribution of microorganisms in many supraglacial ecosystems, much slower climatic and glacial mass-balance processes effect such changes in the subglacial ecosystem. Paradoxically, it is shown that these forces have brought about net refreezing and the onset of cryostasis in the subglacial ecosystems of many Arctic glaciers subject to thinning in recent decades.
}, keywords = {LTER-MCM, Biggie, snow ecology}, doi = {10.1890/07-0187.1}, url = {http://dx.doi.org/10.1890/07-0187.1}, author = {Hodson, A and Alexandre M. Anesio and Martyn Tranter and Andrew G Fountain and Osborn, M and John C. Priscu and Johanna Laybourn-Parry and Sattler, B} } @article {1221, title = {Plankton Dynamics in the McMurdo Dry Valley Lakes During the Transition to Polar Night - A Project Contributing to EBA}, journal = {SCAR EBA (Evolution and Biodiversity in the Antarctic) Newsletter, October 2008}, volume = {2}, year = {2008}, keywords = {LTER-MCM}, doi = {LTER}, author = {John C. Priscu} } @article {1223, title = {SPME-GCMS study of the natural attenuation of aviation diesel spilled on the perennial ice cover of Lake Fryxell, Antarctica}, journal = {Science of the Total Environment}, volume = {407}, year = {2008}, pages = {250-262}, keywords = {LTER-MCM}, author = {Jaraula, C and Kenig, Fabien and Peter T. Doran and John C. Priscu and Kathleen A. Welch} } @article {1225, title = {Supersaturated N2O in a perennially ice-covered Antarctic lake: Molecular and stable isotopic evidence for a biogeochemical relict.}, journal = {Limnology and Oceanography}, volume = {53}, year = {2008}, pages = {2439-2450}, keywords = {LTER-MCM}, doi = {LTER}, url = {http://brent.xner.net/pdf/Priscu_etal2008_ELB-N2O.pdf}, author = {John C. Priscu and Brent C. Christner and John E. Dore and Marian B. Westley and Brian N. Popp and Karen L. Casciotti and W. Berry Lyons} } @article {1238, title = {Bacterial diversity associated with Blood Falls, A subglacial outflow from the Taylor Glacier, Antarctica}, journal = {Applied and Environmental Microbiology}, volume = {73}, year = {2007}, pages = {4029-4039}, keywords = {LTER-MCM}, doi = {LTER}, author = {Jill A. Mikucki and John C. Priscu} } @article {1236, title = {Biogeochemical stoichiometry of Antarctic Dry Valley ecosystems}, journal = {Journal of Geophysical Research}, volume = {112}, year = {2007}, month = {02/2007}, pages = {G01010+12}, abstract = {

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.

}, keywords = {LTER-MCM, Biggie}, doi = {10.1029/2005JG000141}, author = {John E. Barrett and Ross A. Virginia and W. Berry Lyons and Diane M. McKnight and John C. Priscu and Andrew G Fountain and Diana H. Wall and Daryl L. Moorhead and Peter T. Doran} } @article {1245, title = {Metabolic activity and diversity of cryoconites in the Taylor Valley, Antarctica}, journal = {Journal of Geophysical Research}, volume = {112}, year = {2007}, keywords = {LTER-MCM}, doi = {LTER}, author = {Christine M. Foreman and Sattler, B and Jill A. Mikucki and Porazinska, D and John C. Priscu} } @mastersthesis {1246, title = {Microbial Processes in the Moats of Lakes in the Taylor Valley, Antarctica}, volume = {M.S.}, year = {2007}, school = {Montana State University}, type = {masters}, keywords = {LTER-MCM}, doi = {LTER}, author = {Moore, J} } @article {1257, title = {Adaptation and acclimation of photosynthetic microorganisms to permanently cold environments}, journal = {Microbial and Molecular Biology Review}, volume = {70}, year = {2006}, month = {03/2006}, pages = {222-252}, abstract = {

Persistently cold environments constitute one of our world\&$\#$39;s largest ecosystems, and microorganisms dominate the biomass and metabolic activity in these extreme environments. The stress of low temperatures on life is exacerbated in organisms that rely on photoautrophic production of organic carbon and energy sources. Phototrophic organisms must coordinate temperature-independent reactions of light absorption and photochemistry with temperature-dependent processes of electron transport and utilization of energy sources through growth and metabolism. Despite this conundrum, phototrophic microorganisms thrive in all cold ecosystems described and (together with chemoautrophs) provide the base of autotrophic production in low-temperature food webs. Psychrophilic (organisms with a requirement for low growth temperatures) and psychrotolerant (organisms tolerant of low growth temperatures) photoautotrophs rely on low-temperature acclimative and adaptive strategies that have been described for other low-temperature-adapted heterotrophic organisms, such as cold-active proteins and maintenance of membrane fluidity. In addition, photoautrophic organisms possess other strategies to balance the absorption of light and the transduction of light energy to stored chemical energy products (NADPH and ATP) with downstream consumption of photosynthetically derived energy products at low temperatures. Lastly, differential adaptive and acclimative mechanisms exist in phototrophic microorganisms residing in low-temperature environments that are exposed to constant low-light environments versus high-light- and high-UV-exposed phototrophic assemblages.

}, keywords = {LTER-MCM, Biggie}, doi = {10.1128/​MMBR.70.1.222-252.2006}, author = {Rachael M. Morgan-Kiss and John C. Priscu and Pocock, T and Gudynaite-Savitch, L and Norman P.A. Huner} } @inbook {1260, title = {Antarctic lake systems and climate change}, booktitle = {Trends in Antarctic Terrestrial and Limnetic Ecosystems: Antarctica as a Global Indicator}, year = {2006}, publisher = {S}, organization = {S}, address = {Dordrecht, The Netherlands}, keywords = {LTER-MCM}, doi = {LTER}, author = {W. Berry Lyons and Johanna Laybourn-Parry and Kathleen A. Welch and John C. Priscu}, editor = {D.M. Bergstrom and Peter Convey and A.H.L. Huiskes} } @article {1268, title = {Fuel movement between grain boundaries in ice}, journal = {Cold Regions Science and Technology}, volume = {45}, year = {2006}, pages = {158-165}, keywords = {LTER-MCM}, doi = {LTER}, author = {Steven M. Jepsen and Edward E. Adams and John C. Priscu} } @article {1293, title = {Comment on {\textquoteleft}{\textquoteleft}El Ni{\~n}o suppresses Antarctic warming{\textquoteright}{\textquoteright} by N. Bertler et al.}, journal = {Geophysical Research Letters}, volume = {32}, year = {2005}, pages = {L07706}, keywords = {LTER-MCM, Tropical meteorology}, doi = {10.1029/2004GL021716}, author = {Peter T. Doran and Gary D. Clow and Christian H. Fritsen and Christopher P. McKay and Andrew N. Parsons and John C. Priscu and W. Berry Lyons and Walsh, J and Andrew G Fountain and Diane M. McKnight and Daryl L. Moorhead and Ross A. Virginia and Diana H. Wall} } @article {1296, title = {An Ecosystem of Superlatives}, journal = {Bioscience}, volume = {55}, year = {2005}, pages = {804-806}, keywords = {LTER-MCM}, doi = {10.1641/0006-3568(2005)055[0804:AEOS]2.0.CO;2}, url = {http://www.jstor.org/stable/10.1641/0006-3568\%282005\%29055\%5B0804:AEOS\%5D2.0.CO;2}, author = {John C. Priscu} } @article {1298, title = {Glacial ice cores: a model system for developing extraterrestrial decontamination protocols}, journal = {Icarus}, volume = {174}, year = {2005}, pages = {572-584}, keywords = {LTER-MCM}, doi = {LTER}, url = {/reports/lakes/ChristnerEtAl2005Decontamination.pdf}, author = {Brent C. Christner and Jill A. Mikucki and Christine M. Foreman and Denson, J and John C. Priscu} } @phdthesis {1302, title = {Microbial Ecology of an Antarctic Subglacial Environment}, volume = {Ph.D.}, year = {2005}, school = {Montana State University}, type = {doctoral}, keywords = {LTER-MCM}, doi = {LTER}, author = {Jill A. Mikucki} } @inbook {1304, title = {Perennial Antarctic lake ice: A refuge for cyanobacteria in an extreme environment}, booktitle = {Life in Ancient Ice}, year = {2005}, pages = {22-49}, publisher = {Princeton University Press}, organization = {Princeton University Press}, keywords = {LTER-MCM}, url = {http://www.montana.edu/lkbonney/DOCS/Publications/PriscuEtAl2005CyanobacteriaRefuge.pdf}, author = {John C. Priscu and Edward E. Adams and Hans W. Paerl and Christian H. Fritsen and John E. Dore and John T. Lisle and Craig F. Wolf and Jill A. Mikucki}, editor = {S. O. Rogers and J. Castello} } @article {1305, title = {Perturbation of hydrochemical conditions in natural microcosms entombed within Antarctic ice}, journal = {Ice and Climate News}, volume = {6}, year = {2005}, pages = {22-23}, keywords = {LTER-MCM}, author = {Martyn Tranter and Andrew G Fountain and Christian H. Fritsen and W. Berry Lyons and John C. Priscu and Stratham, P and Kathleen A. Welch} } @inbook {1306, title = {Polar lakes, streams, and springs as analogs for the hydrological cycle on Mars.}, booktitle = {Advances in Astrobiology and Biogeophysics}, year = {2005}, pages = {219-233}, publisher = {Springer Verlag}, organization = {Springer Verlag}, address = {Berlin, Heidelberg}, keywords = {LTER-MCM}, doi = {LTER}, url = {/reports/lakes/McKayEtAl2005StreamsSprings.pdf}, author = {Christopher P. McKay and Dale T. Andersen and Pollard, W and Heldmann, J and Peter T. Doran and Christian H. Fritsen and John C. Priscu} } @article {1324, title = {The Carbon Isotopic Composition of Dissolved Inorganic Carbon in Perennially Ice-Covered Antarctica Lakes: Searching for a Biogenic Signature.}, journal = {Annals of Glaciology}, volume = {39}, year = {2004}, keywords = {LTER-MCM}, author = {Klaus Neumann and W. Berry Lyons and John C. Priscu and David J. DesMarais and Kathleen A. Welch} } @article {1328, title = {The distribution of microplankton in the McMurdo dry valley lakes, Antarctica: Response to ecosystem legacy or present-day climate controls?}, journal = {Polar Biology}, volume = {27}, year = {2004}, pages = {238-249}, keywords = {LTER-MCM}, doi = {LTER}, author = {Emily C. Roberts and John C. Priscu and Craig F. Wolf and W. Berry Lyons and Johanna Laybourn-Parry} } @inbook {1329, title = {Earth{\textquoteright}s Icy Biosphere}, booktitle = {Microbial Diversity and Bioprospecting}, year = {2004}, publisher = {American Society for Microbiology}, organization = {American Society for Microbiology}, keywords = {LTER-MCM}, doi = {LTER}, url = {http://mcm.lternet.edu/reports/lakes/PriscuChristner2004IcyBiosphere.pdf}, author = {John C. Priscu and Brent C. Christner}, editor = {Bull, Alan T.} } @article {1330, title = {Elevated levels of dimethylated-sulfur compounds in Lake Bonney, a poorly ventilated Antarctic lake}, journal = {Limnology and Oceanography}, volume = {49}, year = {2004}, pages = {1044-1055}, keywords = {LTER-MCM}, author = {Lee, P and John C. Priscu and G R DiTullio and Riseman, S and Tursich, N and DeMora, S} } @article {1331, title = {Extreme hydrochemical conditions in natural microcosms entombed within Antarctic ice.}, journal = {Hydrological Processes}, volume = {18}, year = {2004}, pages = {379-387}, keywords = {LTER-MCM}, author = {Martyn Tranter and Andrew G Fountain and Christian H. Fritsen and W. Berry Lyons and John C. Priscu and Stathan, P and Kathleen A. Welch} } @article {1333, title = {Geomicrobiology of Blood Fall: An iron-rich saline discharge at the terminus of the Taylor Glacier, Antarctica}, journal = {Aquatic Geochemistry}, volume = {10}, year = {2004}, pages = {199-200}, keywords = {LTER-MCM}, author = {Jill A. Mikucki and Christine M. Foreman and Sattler, B and W. Berry Lyons and John C. Priscu} } @article {1334, title = {Identification of a psychrophilic green alga from Lake Bonney, Antarctica: Chlamydomonas raudensis ETTL. (UWO 241) (Chlorophyceae)}, journal = {Journal of Phycology}, volume = {40}, year = {2004}, pages = {1138-1148}, keywords = {LTER-MCM}, author = {Pocock, T and Lachance, M and Proschold, T and John C. Priscu and Kim, S and Norman P.A. Huner} } @article {1320, title = {Impact of episodic warming events on the physical, chemical and biological relationships of lakes in the McMurdo Dry Valleys, Antarctica}, journal = {Aquatic Geochemistry}, volume = {10}, year = {2004}, month = {09/2004}, pages = {239-268}, type = {Journal}, keywords = {LTER-MCM, Climate Response, stoichiometry}, doi = {10.1007/s10498-004-2261-3}, url = {http://link.springer.com/article/10.1007\%2Fs10498-004-2261-3}, author = {Christine M. Foreman and Wolf, C and John C. Priscu} } @article {1336, title = {Microplankton dynamics in a perennially ice-covered Antarctic lake-Lake Hoare}, journal = {Freshwater Biology}, volume = {27}, year = {2004}, pages = {238-249}, keywords = {LTER-MCM}, author = {Emily C. Roberts and John C. Priscu and Johanna Laybourn-Parry} } @article {1338, title = {The Occurrence of Lysogenic Bacteria and Microbial Aggregates in the Lakes of the McMurdo Dry Valleys, Antarctica}, journal = {Microbial Ecology}, volume = {47}, year = {2004}, pages = {427-439}, keywords = {LTER-MCM}, author = {John T. Lisle and John C. Priscu} } @inbook {1339, title = {Paleolimnology of extreme cold terrestrial and extraterrestrial environments.}, booktitle = {Long-Term Environmental Change in Arctic and Antarctic Lakes}, year = {2004}, pages = {475-507}, publisher = {Kluwer Academic Publishers}, organization = {Kluwer Academic Publishers}, address = {Dordrecht, The Netherlands}, keywords = {LTER-MCM}, isbn = {978-1-4020-2125-1}, author = {Peter T. Doran and John C. Priscu and W. Berry Lyons and Powell, R and Robert J. Poreda and Dale T. Andersen} } @inbook {1340, title = {Paleolimnology of Ice-covered Environments}, booktitle = {Long-term environmental change in Arctic and Antarctic lakes}, year = {2004}, pages = {475-507}, publisher = {Kluwer Academic Publishers}, organization = {Kluwer Academic Publishers}, keywords = {LTER-MCM}, author = {Peter T. Doran and John C. Priscu and W. Berry Lyons and Powell, R and Robert J. Poreda}, editor = {Pienitz, R and Douglas, Marianne S. V. and John Smol} } @article {1343, title = {Stable carbon and nitrogen isotopic compositions of benthic and pelagic organic matter in four polar lakes of the McMurdo Dry Valleys, Antarctica}, journal = {Aquatic Geochemistry}, volume = {10}, year = {2004}, pages = {269-301}, keywords = {LTER-MCM}, author = {Lawson, J and Peter T. Doran and Kenig, Fabien and David J. DesMarais and John C. Priscu} } @article {1345, title = {Thermodynamic constraints on microbially mediated processes in lakes of the McMurdo Dry Valleys, Antarctica}, journal = {Geomicrobiology Journal}, volume = {21}, year = {2004}, pages = {1-17}, keywords = {LTER-MCM}, doi = {LTER}, author = {Lee, P and Jill A. Mikucki and Christine M. Foreman and John C. Priscu and G R DiTullio and Riseman, S and DeMora, S and Craig F. Wolf and Kester, L} } @article {1358, title = {Biochemistry of Si in the McMurdo Dry Valley lakes, Antarctica}, journal = {The International Journal of Astrobiology}, volume = {1}, year = {2003}, pages = {737-749}, keywords = {LTER-MCM}, author = {Pugh, H and Kathleen A. Welch and W. Berry Lyons and John C. Priscu and Diane M. McKnight} } @article {1357, title = {Formation and character of an ancient 19 m ice cover and underlying trapped brine in an}, journal = {Proceedings of National Academy of Sciences}, volume = {100}, year = {2003}, month = {01/2003}, pages = {26-31}, type = {Journal}, keywords = {LTER-MCM}, doi = {10.1073/pnas.222680999}, url = {http://www.pnas.org/content/100/1/26.short}, author = {Peter T. Doran and Christian H. Fritsen and Christopher P. McKay and John C. Priscu and Edward E. Adams} } @mastersthesis {1367, title = {Spatial and temporal variations of phytoplankton populations in Lake Bonney}, volume = {M.S.}, year = {2003}, school = {Montana State University}, type = {masters}, keywords = {LTER-MCM}, doi = {LTER}, author = {Turish, N} } @article {1377, title = {Antarctic climate cooling and terrestrial ecosystem response}, journal = {Nature}, volume = {415}, year = {2002}, month = {01/2002}, pages = {517-520}, type = {Journal}, keywords = {LTER-MCM, Climate Response}, doi = {10.1038/nature710}, author = {Peter T. Doran and John C. Priscu and W. Berry Lyons and John E. Walsh and Andrew G Fountain and Diane M. McKnight and Daryl L. Moorhead and Ross A. Virginia and Diana H. Wall and Gary D. Clow and Christian H. Fritsen and Christopher P. McKay and Andrew N. Parsons} } @inbook {1380, title = {Extremophiles: ice ecosystems and biodiversity}, booktitle = {Knowledge for Sustainable Development: an Insight into the Encyclopedia of Life Support Systems.}, year = {2002}, pages = {573-598}, publisher = {UNESCO Publishing-Eolss Publishers}, organization = {UNESCO Publishing-Eolss Publishers}, address = {Oxford}, keywords = {LTER-MCM}, author = {Psenner, R and Felip, M and John C. Priscu and Wagenbach, D and Willie, A and Sattler, B} } @mastersthesis {1381, title = {Linkages between soils and lake ice sediments biogeochemistry: Taylor Valley, southern Victoria Land, Antarctica}, volume = {M.S.}, year = {2002}, school = {Montana State University}, type = {masters}, keywords = {LTER-MCM}, doi = {LTER}, author = {Konley, S} } @article {1382, title = {Recent Temperature Trends in the Antarctic}, journal = {Nature}, volume = {418}, year = {2002}, pages = {291-292}, keywords = {LTER-MCM}, author = {John E. Walsh and Gary D. Clow and Christian H. Fritsen and Christopher P. McKay and Andrew N. Parsons and Peter T. Doran and John C. Priscu and W. Berry Lyons and Andrew G Fountain and Diane M. McKnight and Daryl L. Moorhead and Ross A. Virginia and Diana H. Wall} } @article {1398, title = {Bacterial dissolved organic carbon demand in antarctic dry valley lakes}, journal = {Limnology and Oceanography}, volume = {46}, year = {2001}, month = {07/2001}, pages = {1189-1194}, type = {Journal}, keywords = {LTER-MCM, Biggie}, doi = {10.4319/lo.2001.46.5.1189}, url = {http://www.jstor.org/stable/2671031}, author = {Cristina D. Takacs-Vesbach and John C. Priscu and Diane M. McKnight} } @article {1401, title = {CO2 concentrations in perennially ice-covered lakes of Taylor Valley, Antarctica}, journal = {Biogeochemistry}, volume = {56}, year = {2001}, pages = {27-50}, keywords = {LTER-MCM}, author = {Klaus Neumann and W. Berry Lyons and John C. Priscu and Donahoe, R} } @article {1404, title = {The McMurdo Dry Valleys Long-Term Ecological Research Program: new understanding of the biogeochemistry of the Dry Valley lakes: a review.}, journal = {Polar Geography}, volume = {25}, year = {2001}, pages = {202-217}, keywords = {LTER-MCM}, author = {W. Berry Lyons and Kathleen A. Welch and John C. Priscu and Johanna Laybourn-Parry and Daryl L. Moorhead and Diane M. McKnight and Peter T. Doran and Martyn Tranter} } @article {1397, title = {Phytoplankton phosphorus deficiency and alkaline phosphatase activity in the McMurdo Dry Valley lakes, Antarctica.}, journal = {Limnology and Oceanography}, volume = {46}, year = {2001}, month = {09/2001}, pages = {1331-1346}, type = {Journal}, keywords = {LTER-MCM}, author = {John E. Dore and John C. Priscu} } @article {1427, title = {Distribution and phylogeny of bacterial communities associated with mineral particles in Antarctic lake ice.}, journal = {Microbial Biology}, volume = {39}, year = {2000}, pages = {197-202}, keywords = {LTER-MCM}, author = {Douglas A. Gordon and John C. Priscu and Stephen J. Giovannoni} } @article {1428, title = {Distribution of organic carbon and nitrogen in surface soils in the McMurdo Dry Valleys, Antarctica.}, journal = {Polar Biology}, volume = {23}, year = {2000}, pages = {121-128}, keywords = {LTER-MCM}, author = {Christian H. Fritsen and Grue, A and John C. Priscu} } @article {1432, title = {The importance of landscape position and legacy: The evolution of the Taylor Valley Lake District, Antarctica.}, journal = {Freshwater Biology}, volume = {43}, year = {2000}, pages = {355-367}, keywords = {LTER-MCM}, author = {W. Berry Lyons and Andrew G Fountain and Peter T. Doran and John C. Priscu and Klaus Neumann and Kathleen A. Welch} } @article {1450, title = {Carbon transformations in a perennially ice-covered Antarctic lake}, year = {1999}, keywords = {LTER-MCM}, author = {John C. Priscu and Craig F. Wolf and Cristina D. Takacs-Vesbach and Christian H. Fritsen and Johanna Laybourn-Parry and Emily C. Roberts and Birgit Sattl} } @article {1455, title = {The distribution and relative abundance of ammonium-oxidizing bacteria in lakes of the McMurdo Dry Valleys, Antarctica}, journal = {Hydrobiologia}, volume = {401}, year = {1999}, pages = {113-130}, keywords = {LTER-MCM}, doi = {LTER}, author = {Mary A. Voytek and John C. Priscu and Bess B. Ward} } @article {1459, title = {Geomicrobiology of sub-glacial ice above Vostok Station}, journal = {Science}, volume = {286}, year = {1999}, pages = {2141-2144}, keywords = {LTER-MCM}, doi = {10.1126/science.286.5447.2141}, author = {John C. Priscu and Edward E. Adams and W. Berry Lyons and Mary A. Voytek and David W. Mogk and Robert L. Brown and Christopher P. McKay and Cristina D. Takacs-Vesbach and Kathleen A. Welch and Craig F. Wolf and Julie D. Kirshtein and Recep Avci} } @article {1464, title = {Lake ice microbial communities in alpine and Antarctic lakes}, year = {1999}, keywords = {LTER-MCM}, author = {Psenner, R and Sattler, B and Willie, A and Christian H. Fritsen and John C. Priscu and Felip, M and J. Catalan} } @article {1446, title = {Life in the valley of the dead}, journal = {Bioscience}, volume = {49}, year = {1999}, month = {12/1999}, pages = {959-960}, keywords = {LTER-MCM}, doi = {LTER}, author = {John C. Priscu} } @article {1447, title = {Physical controls on the Taylor Valley Ecosystem, Antarctica}, journal = {BioScience}, volume = {49}, year = {1999}, month = {12/1999}, pages = {961-972}, type = {Journal}, keywords = {LTER-MCM, Water availability}, author = {Andrew G Fountain and W. Berry Lyons and Melody B. Burkins and Gayle L. Dana and Peter T. Doran and Karen J. Lewis and Diane M. McKnight and Daryl L. Moorhead and Andrew N. Parsons and John C. Priscu and Diana H. Wall and Robert A. Wharton Jr. and Ross A. Virginia} } @article {1470, title = {Seasonal change in the optical properties of the permanent ice cover on Lake Bonney, Antarctica: Consequences for lake productivity and phytoplankton dynamics}, journal = {Limnology and Oceanography}, volume = {44}, year = {1999}, pages = {447-454}, keywords = {LTER-MCM}, author = {Christian H. Fritsen and John C. Priscu} } @article {1485, title = {The Abundance of Ammonium-Oxidizing Bacteria in Lake Bonney, Antarctica Determined by Immunofluorescence, PCR and In Situ Hybridization, in Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica}, journal = {Antarctic Research Series}, volume = {72}, year = {1998}, pages = {217-228}, keywords = {LTER-MCM}, author = {Mary A. Voytek and Bess B. Ward and John C. Priscu} } @article {1486, title = {Antarctic lake-ice microbial consortia: Origin, distribution, and growth physiology}, journal = {Antarctic Journal of the United States - 1996 Review Issue (NSF 98-28)}, volume = {31}, year = {1998}, pages = {223-224}, keywords = {LTER-MCM}, author = {John C. Priscu and Christian H. Fritsen} } @article {1487, title = {Bacterioplankton dynamics in the McMurdo Dry Valley lakes, Antarctica: Production and biomass loss over four seasons}, journal = {Microbial Ecology}, volume = {36}, year = {1998}, pages = {239-250}, keywords = {LTER-MCM}, author = {Cristina D. Takacs-Vesbach and John C. Priscu} } @article {1490, title = {Cyanobacterial assemblages in permanent ice covers on Antarctic lakes: distribution, growth rate, and temperature response of photosynthesis}, journal = {Journal of Phycology}, volume = {34}, year = {1998}, pages = {587-597}, keywords = {LTER-MCM}, author = {Christian H. Fritsen and John C. Priscu} } @article {1491, title = {Cyanobacterial communities associated with mineral particles in antarctic lake ice}, journal = {Antarctic Journal of the United States - 1996 Review Issue (NSF 98-28)}, volume = {31}, year = {1998}, pages = {224-225}, keywords = {LTER-MCM}, author = {Douglas A. Gordon and Brian D. Lanoil and Stephen J. Giovannoni and John C. Priscu} } @inbook {1538, title = {Ecosystem dynamics in a polar desert: the McMurdo Dry Valleys, Antarctica (American Geophysical Union Antarctic Research Series. Volume 72)}, booktitle = {Ecosystem dynamics in a polar desert: the McMurdo Dry Valleys, Antarctica (American Geophysical Union Antarctic Research Series. Volume 72)}, year = {1998}, keywords = {LTER-MCM}, author = {John C. Priscu} } @article {1497, title = {Fluorescence Quenching in Phytoplankton of the McMurdo Dry Valley Lakes (Antarctica): Implications for the Structure and Function of the Photosynthetic Apparatus, in Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica}, journal = {Antarctic Research Series}, volume = {72}, year = {1998}, pages = {241-253}, keywords = {LTER-MCM}, author = {Patrick J. Neale and John C. Priscu} } @inbook {1499, title = {Geochemical Linkages Among Glaciers, Streams, and Lakes Within the Taylor Valley, Antarctica}, booktitle = {Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica}, volume = {72}, year = {1998}, pages = {77-92}, keywords = {LTER-MCM}, author = {W. Berry Lyons and Kathleen A. Welch and Klaus Neumann and Jeffrey K. Toxey and Robyn McArthur and Changela Williams and Diane M. McKnight and Daryl L. Moorhead} } @article {1539, title = {A lesson from the bottom of the earth}, journal = {Bioscience}, volume = {48}, year = {1998}, pages = {843-847}, keywords = {LTER-MCM}, author = {John C. Priscu} } @article {1505, title = {The McMurdo Dry Valley Ecosystem: Organization, Controls, and Linkages, in Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica}, journal = {Antarctic Research Series}, volume = {72}, year = {1998}, pages = {351-363}, keywords = {LTER-MCM}, author = {Daryl L. Moorhead and John C. Priscu} } @article {1511, title = {McMurdo Dry Valleys LTER: Phosphorus deficiency and alkaline phosphatase activity in lakes of Taylor Valley, Antarctica}, journal = {Antarctic Journal of the United States - 1996 Review Issue (NSF 98-28)}, volume = {31}, year = {1998}, pages = {206-208}, keywords = {LTER-MCM}, author = {John E. Dore and John C. Priscu} } @article {1516, title = {Microbial phototrophic, heterotrophic, and diazotrophic activities associated with aggregates in the permanent ice cover of Lake Bonney, Antarctica}, journal = {Microbial Ecology}, volume = {36}, year = {1998}, pages = {221-230}, keywords = {LTER-MCM}, author = {Hans W. Paerl and John C. Priscu} } @article {1519, title = {Nitrogen fixation within permanent ice covers on lakes in the McMurdo Dry Valleys, Antarctica}, journal = {Antarctic Journal of the United States - 1996 Review Issue (NSF 98-28)}, volume = {31}, year = {1998}, pages = {218-220}, keywords = {LTER-MCM}, author = {Amanda M. Grue and Christian H. Fritsen and John C. Priscu} } @inbook {1520, title = {Optical Properties of the McMurdo Dry Valley Lakes, Antarctica}, booktitle = {Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica}, series = {Antarctic Research Series}, volume = {72}, year = {1998}, pages = {189-203}, keywords = {LTER-MCM}, author = {Clive Howard-Williams and Anne-Maree Schwarz and Ian Hawes and John C. Priscu} } @article {1482, title = {Perennial Antarctic Lake Ice: An Oasis for Life in a Polar Desert}, journal = {Science}, volume = {280}, year = {1998}, month = {06/1998}, pages = {2095-2098}, type = {Journal}, keywords = {LTER-MCM, Biggie}, doi = {10.1126/science.280.5372.2095}, url = {http://www.sciencemag.org/content/280/5372/2095.short}, author = {John C. Priscu and Christian H. Fritsen and Edward E. Adams and Stephen J. Giovannoni and Hans W. Paerl and Christopher P. McKay and Peter T. Doran and Douglas A. Gordon and Brian D. Lanoil and James L. Pinckney} } @inbook {1521, title = {Permanent Ice Covers of the McMurdo Dry Valley Lakes, Antarctica: Bubble Formation and Metamorphism}, booktitle = {Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica}, series = {Antarctic Research Series}, volume = {72}, year = {1998}, pages = {281-295}, keywords = {LTER-MCM}, author = {Edward E. Adams and John C. Priscu and Christian H. Fritsen and Scott R.Smith and Steven L. Brackman} } @inbook {1522, title = {Permanent Ice Covers of the McMurdo Dry Valleys Lakes, Antarctica: Liquid Water Contents}, booktitle = {Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica}, series = {Antarctic Research Series}, volume = {72}, year = {1998}, pages = {269-280}, keywords = {LTER-MCM}, author = {Christian H. Fritsen and Edward E. Adams and Christopher P. McKay and John C. Priscu} } @article {1523, title = {Photosynthetic characteristics of cyanobacteria in permanent ice covers on lakes in the McMurdo Dry Valleys, Antarctica}, journal = {Antarctic Journal of the United States - 1996 Review Issue (NSF 98-28)}, volume = {31}, year = {1998}, pages = {216-218}, keywords = {LTER-MCM}, author = {Christian H. Fritsen and John C. Priscu} } @article {1524, title = {Physical Limnology of the McMurdo Dry Valleys Lakes, in Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica}, journal = {Antarctic Research Series}, volume = {72}, year = {1998}, pages = {153-187}, keywords = {LTER-MCM}, author = {Spigel, Robert H. and John C. Priscu} } @inbook {1525, title = {Pigment Analysis of the Distribution, Succession, and Fate of Phytoplankton in the McMurdo Dry Valley Lakes of Antarctica}, booktitle = {Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica}, series = {Antarctic Research Series}, volume = {72}, year = {1998}, pages = {229-239}, keywords = {LTER-MCM}, author = {Michael P. Lizotte and John C. Priscu} } @article {1528, title = {The role of phytoplankton extracellular release in bacterioplankton growth of Taylor Valley Lakes, Antarctica}, journal = {Antarctic Journal of the United States - 1996 Review Issue (NSF 98-28)}, volume = {31}, year = {1998}, pages = {211-212}, keywords = {LTER-MCM}, author = {Cristina D. Takacs-Vesbach and John C. Priscu} } @article {1532, title = {Structure and composition of the photochemical apparatus of the Antarctic green alga Chlamydomonas subcaudata}, journal = {Photosynthesis Research - Regular Paper}, volume = {56}, year = {1998}, pages = {303-314}, keywords = {LTER-MCM}, author = {Morgan, Rachael M. and Alexander G. Ivanov and John C. Priscu and Denis P. Maxwell and Norman P.A. Huner} } @article {1534, title = {Transparency of Antarctic ice-covered lakes to solar UV radiation}, journal = {Limnol. Oceanogr.}, volume = {43}, year = {1998}, pages = {618-624}, keywords = {LTER-MCM}, author = {Warwick F. Vincent and Rowena Rae and Isabelle Laurion and Clive Howard-Williams and John C. Priscu} } @article {1566, title = {The Biogeochemistry of Nitrous Oxide in Permanently Ice-Covered Lakes of the McMurdo Dry Valleys, Antarctica}, journal = {Global Change Biology}, volume = {3}, year = {1997}, pages = {301-315}, keywords = {LTER-MCM}, author = {John C. Priscu} } @article {1551, title = {Detection and Characterization of Denitrifying Bacteria from a Permanently Ice-Covered Antarctic Lake}, journal = {Hydrobiologia}, volume = {347}, year = {1997}, pages = {57-68}, keywords = {LTER-MCM}, author = {Bess B. Ward and John C. Priscu} } @article {1560, title = {The microbial plankton of Lake Fryxell, southern Victoria Land, Antarctica during the summers of 1992 and 1994}, journal = {Polar Biology}, volume = {17}, year = {1997}, pages = {54-61}, keywords = {LTER-MCM}, author = {Johanna Laybourn-Parry and Mark R. James and Diane M. McKnight and John C. Priscu and Sarah A. Spaulding and Russell Shiel} } @article {1568, title = {Bacterial growth in Antarctic lakes: The role of phytoplankton extracellular release}, journal = {Bacterial growth in Antarctic lakes: The role of phytoplankton extracellular}, year = {1996}, keywords = {LTER-MCM}, author = {Cristina D. Takacs-Vesbach and John C. Priscu} } @article {1571, title = {Evolution of Temperature and Salt Structure of Lake Bonney, a Chemically Stratified Antarctic Lake}, journal = {Hydrobiologia}, volume = {321}, year = {1996}, pages = {177-190}, keywords = {LTER-MCM}, author = {Spigel, Robert H. and John C. Priscu} } @article {1572, title = {Extreme Supersaturation of Nitrous Oxide in a Poorly Ventilated Antarctic Lake}, journal = {Limnol. Oceanogr}, volume = {41}, year = {1996}, pages = {1544-1551}, keywords = {LTER-MCM}, author = {John C. Priscu and Malcolm T. Downes and Christopher P. McKay} } @article {1578, title = {Phytoplankton Dynamics in the Stratified Water Column of Lake Bonney, Antarctica. I. Biomass and Productivity During the Winter-Spring Transition}, journal = {Polar Biology}, volume = {16}, year = {1996}, pages = {155-162}, keywords = {LTER-MCM}, author = {Michael P. Lizotte and Thomas R. Sharp and John C. Priscu} } @article {1592, title = {McMurdo LTER: Relationships between vertical nutrient flux and phytoplankton biomass and productivity in lakes of the Taylor Valley, Antarctica}, journal = {Antarctic Journal of the U.S.}, volume = {30}, year = {1995}, pages = {294-295}, keywords = {LTER-MCM}, author = {R. L. Edwards and John C. Priscu} } @article {1597, title = {The Photosynthetic Apparatus of Phytoplankton from a Perennially Ice-Covered Antarctic Lake: Acclimation to an Extreme Shade Environment}, journal = {Plant Cell Physiology}, volume = {36}, year = {1995}, pages = {253-263}, keywords = {LTER-MCM}, author = {Patrick J. Neale and John C. Priscu} } @article {1598, title = {Phototactic response of phytoplankton forming discrete layers within the water column of Lake Bonney , Antarctica}, journal = {Antarctic Journal of the US}, volume = {30}, year = {1995}, pages = {301-303}, keywords = {LTER-MCM}, author = {John C. Priscu and Patrick J. Neale} } @article {1599, title = {Phytoplankton Nutrient Deficiency in Lakes of the McMurdo Dry Valleys, Antarctica}, journal = {Freshwater Biology}, volume = {34}, year = {1995}, pages = {215-227}, keywords = {LTER-MCM, legacy}, author = {John C. Priscu} } @article {1600, title = {Profiles of electrode potential and dissolved oxygen in lakes of the McMurdo Dry Valleys}, journal = {Antarctic Journal of the U.S.}, volume = {30}, year = {1995}, pages = {305-307}, keywords = {LTER-MCM}, author = {Malcolm T. Downes and John C. Priscu} } @article {1602, title = {Responses of bacterial growth to inorganic and organic nutrient enrichment in the lakes of the dry valleys, Antarctica}, journal = {Antarctic Journal of the US}, volume = {30}, year = {1995}, pages = {303-305}, keywords = {LTER-MCM}, author = {Cristina D. Takacs-Vesbach and John C. Priscu} } @article {1604, title = {Some metamorphic processes in the lake ice of the McMurdo Dry Valleys}, journal = {Antarctic Journal of the U.S.}, volume = {30}, year = {1995}, pages = {307-309}, keywords = {LTER-MCM}, author = {Edward E. Adams and John C. Priscu and Atsushi Sato} } @article {1617, title = {McMurdo LTER: Inorganic geochemical studies with special reference to calcium carbonate dynamics}, journal = {Antarctic Journal of the U.S.}, volume = {29}, year = {1994}, pages = {237-239}, keywords = {LTER-MCM}, author = {Kathleen A. Welch and W. Berry Lyons and John C. Priscu and R. L. Edwards and Diane M. McKnight and Harold R. House and Robert A. Wharton Jr.} } @article {1631, title = {McMurdo LTER: Phytoplankton nutrient deficiency in lakes of the Taylor Valley, Antarctica}, journal = {Antarctic Journal of the U.S.}, volume = {29}, year = {1994}, pages = {239-241}, keywords = {LTER-MCM}, author = {John C. Priscu} } @article {1623, title = {Natural Fluorescence and Quantum Yields in Vertically Stationary Phytoplankton from Perennially Ice-Covered Lakes}, journal = {Limnol. Oceanogr.}, volume = {39}, year = {1994}, pages = {1399-1410}, keywords = {LTER-MCM}, author = {Michael P. Lizotte and John C. Priscu} } @article {1648, title = {Book Review: Physical and biogeochemical processes in Antarctic lakes}, journal = {Limnology and Oceanography}, volume = {39}, year = {1993}, pages = {1499-1500}, keywords = {LTER-MCM}, author = {John C. Priscu} } @article {1637, title = {Influence of high salinity levels on ambient inorganic nitrogen and nitrogen-15 extraction efficiency in Lake Bonney}, journal = {Antarctic Journal of the U.S.}, volume = {28}, year = {1993}, pages = {245-246}, keywords = {LTER-MCM}, author = {Richard D. Bartlett and John C. Priscu and Christopher D. Woolston} } @article {1639, title = {Microbial communities in the permanent ice cap of Lake Bonney, Antarctica: Relationships among chlorophyll-a , gravel, and nutrients.}, journal = {Antarctic Journal of the U.S}, volume = {28}, year = {1993}, pages = {247-249}, keywords = {LTER-MCM}, author = {Wing, Kate T. and John C. Priscu} } @article {1640, title = {Microbial respiration potential in Lake Bonney using a novel tetrazolium-reduction method}, journal = {Antarctic Journal of the U.S.}, volume = {28}, year = {1993}, pages = {244-245}, keywords = {LTER-MCM}, author = {Smith, James J. and John C. Priscu} } @article {1641, title = {Nitrifying and denitrifying bacteria in Lake Bonney}, journal = {Antarctic Journal of the U.S.}, volume = {28}, year = {1993}, pages = {239-241}, keywords = {LTER-MCM}, author = {Bess B. Ward and Cockcroft, A.R. and John C. Priscu} } @article {1643, title = {Phytoplankton utilization of ammonium and nitrate in Lake Bonney: A preliminary assessment.}, journal = {Antarctic Journal of the U.S.}, volume = {28}, year = {1993}, pages = {241-243}, keywords = {LTER-MCM}, author = {Christopher D. Woolston and John C. Priscu} } @article {1647, title = {Water column transformations of nitrogen in Lake Bonney, a perennially ice-covered antarctic lake}, journal = {Antarctic Journal of the U.S.}, volume = {28}, year = {1993}, pages = {237-239}, keywords = {LTER-MCM}, author = {John C. Priscu and Bess B. Ward and Malcolm T. Downes} } @article {1651, title = {Photosynthesis-Irradiance Relationships in Phytoplankton From the Physically Stable Water Column of a Perennially Ice-Covered Lake (Lake Bonney, Antarctica)}, journal = {J. Phycol.}, volume = {28}, year = {1992}, pages = {179-185}, keywords = {LTER-MCM}, author = {Michael P. Lizotte and John C. Priscu} } @article {1652, title = {Spectral Irradiance and Bio-Optical Properties in Perennially Ice-Covered Lakes of the Dry Valleys (McMurdo Sound, Antarctica)}, journal = {Antarctic Research Series}, volume = {57}, year = {1992}, pages = {1-14}, keywords = {LTER-MCM}, author = {Michael P. Lizotte and John C. Priscu} } @article {1654, title = {Development and Application of a Technique for Estimating Nutrient Deficiency in Soft Sediments}, journal = {Hydrobiologia}, volume = {203}, year = {1990}, pages = {93-97}, keywords = {LTER-MCM}, author = {Walter K. Dodds and John C. Priscu} } @article {1657, title = {Inorganic Nitrogen Uptake and Regeneration in Perennially Ice-Covered Lakes Fryxell and Vanda, Antarctica}, journal = {Journal of Plankton Research}, volume = {11}, year = {1989}, pages = {335-351}, keywords = {LTER-MCM}, author = {John C. Priscu and Warwick F. Vincent and Clive Howard-Williams} } @article {1659, title = {Photon Dependence of Inorganic Nitrogen Transport by Phytoplankton in Perennially Ice-Covered Antarctic Lakes}, journal = {Hydrobiologia}, volume = {172}, year = {1989}, pages = {173-182}, keywords = {LTER-MCM}, author = {John C. Priscu} } @article {1658, title = {Temperature Dependence of Inorganic Nitrogen Uptake and Assimilation in Antarctic Sea-Ice Microalgae}, journal = {Polar Biology}, volume = {9}, year = {1989}, pages = {443-446}, keywords = {LTER-MCM}, author = {John C. Priscu and Anna C. Palmisano and Linda R. Priscu and Cornelius W. Sullivan} } @article {1660, title = {Diel Patterns of Photosynthate Biosynthesis by Phytoplankton in Permanently Ice-Covered Antarctic Lakes Under Continuous Sunlight}, journal = {Journal of Plankton Research}, volume = {10}, year = {1988}, pages = {333-340}, keywords = {LTER-MCM}, author = {John C. Priscu and Linda R. Priscu and Clive Howard-Williams and Warwick F. Vincent} } @article {1661, title = {Photosynthate Distribution by Microplankton in Permanently Ice-Covered Antarctic Desert Lakes}, journal = {Limnol. Oceanogr.}, volume = {32}, year = {1987}, pages = {260-270}, keywords = {LTER-MCM}, author = {John C. Priscu and Linda R. Priscu and Warwick F. Vincent and Clive Howard-Williams} }