02505nas a2200325 4500008004100000022001400041245012700055210006900182260001200251300001800263490000800281520146500289653001701754653003701771653002401808653002401832100002701856700002101883700002301904700002201927700002201949700002501971700002001996700002202016700002202038700002202060700002202082700001402104856006102118 2023 eng d a2169-900300aCauses and characteristics of electrical resistivity variability in shallow (<4 m) soils in Taylor Valley, East Antarctica0 aCauses and characteristics of electrical resistivity variability c02/2023 ae2022JF0066960 v1283 a
Airborne electromagnetic surveys collected in December 2011 and November 2018 and three soil sampling transects were used to analyze the spatial heterogeneity of shallow (<4 m) soil properties in lower Taylor Valley (TV), East Antarctica. Soil resistivities from 2011 to 2018 ranged from ∼33 Ωm to ∼3,500 Ωm with 200 Ωm assigned as an upper boundary for brine-saturated sediments. Elevations below ∼50 m above sea level (masl) typically exhibit the lowest resistivities with resistivity increasing at high elevations on steeper slopes. Soil water content was empirically estimated from electrical resistivities using Archie's Law and range from ∼<1% to ∼68% by volume. An increase in silt- and clay-sized particles at low elevations increases soil porosity but decreases hydraulic conductivity, promoting greater residence times of soil water at low elevations near Lake Fryxell. Soil resistivity variability between 2011 and 2018 shows soils at different stages of soil freeze-thaw cycles, which are caused predominantly by solar warming of soils as opposed to air temperature. This study furthers the understanding of the hydrogeologic structure of the shallow subsurface in TV and identifies locations of soils that are potentially prone to greater rates of thaw and resulting ecosystem homogenization of soil properties from projected increases in hydrological connectivity across the region over the coming decades.
10aactive layer10aairborne electromagnetic surveys10aMcMurdo Dry Valleys10apermafrost dynamics1 aGutterman, William, S.1 aDoran, Peter, T.1 aVirginia, Ross, A.1 aBarrett, John, E.1 aMyers, Krista, F.1 aTulaczyk, Slawek, M.1 aFoley, Neil, T.1 aMikucki, Jill, A.1 aDugan, Hilary, A.1 aGrombacher, Denys1 aBording, Thue, S.1 aAuken, E. uhttps://onlinelibrary.wiley.com/doi/10.1029/2022JF00669602152nas a2200253 4500008004100000245012600041210006900167260001200236300001600248490000700264520133900271100002201610700002101632700002501653700002001678700002201698700001701720700002201737700002201759700001901781700002201800700002301822856005301845 2021 eng d00aThermal legacy of a large paleolake in Taylor Valley, East Antarctica, as evidenced by an airborne electromagnetic survey0 aThermal legacy of a large paleolake in Taylor Valley East Antarc c08/2021 a3577 - 35930 v153 aPrevious studies of the lakes of the McMurdo Dry Valleys have attempted to constrain lake level history, and results suggest the lakes have undergone hundreds of meters of lake level change within the last 20 000 years. Past studies have utilized the interpretation of geologic deposits, lake chemistry, and ice sheet history to deduce lake level history; however a substantial amount of disagreement remains between the findings, indicating a need for further investigation using new techniques. This study utilizes a regional airborne resistivity survey to provide novel insight into the paleohydrology of the region. Mean resistivity maps revealed an extensive brine beneath the Lake Fryxell basin, which is interpreted as a legacy groundwater signal from higher lake levels in the past. Resistivity data suggest that active permafrost formation has been ongoing since the onset of lake drainage and that as recently as 1500–4000 years BP, lake levels were over 60 m higher than present. This coincides with a warmer-than-modern paleoclimate throughout the Holocene inferred by the nearby Taylor Dome ice core record. Our results indicate Mid to Late Holocene lake level high stands, which runs counter to previous research finding a colder and drier era with little hydrologic activity throughout the last 5000 years.
1 aMyers, Krista, F.1 aDoran, Peter, T.1 aTulaczyk, Slawek, M.1 aFoley, Neil, T.1 aBording, Thue, S.1 aAuken, Esben1 aDugan, Hilary, A.1 aMikucki, Jill, A.1 aFoged, Nikolaj1 aGrombacher, Denys1 aVirginia, Ross, A. uhttps://tc.copernicus.org/articles/15/3577/2021/01899nas a2200133 4500008004100000245012300041210007100164260001200235520137500247100003101622700002101653700002301674856006801697 2020 eng d00aPicocyanobacterial cells in near‐surface air above terrestrial and freshwater substrates in Greenland and Antarctica0 aPicocyanobacterial cells in near‐surface air above terrestrial a c03/20203 aBioaerosols are an important component of the total atmospheric aerosol load, with implications for human health, climate feedbacks, and the distribution and dispersal of microbial taxa. Bioaerosols are sourced from marine, freshwater, and terrestrial surfaces, with different mechanisms potentially responsible for releasing biological particles from these substrates. Little is known about the production of freshwater and terrestrial bioaerosols in polar regions. We used portable collection devices to test for the presence of picocyanobacterial aerosols above freshwater and soil substrates in the southwestern Greenland tundra and the McMurdo Dry Valleys of Antarctica. We show that picocyanobacterial cells are present in the near‐surface air at concentrations ranging from 2,431 to 28,355 cells m^−3 of air, with no significant differences among substrates or between polar regions. Our concentrations are lower than those measured using the same methods in temperate ecosystems. We suggest that aerosolization is an important process linking terrestrial and aquatic ecosystems in these polar environments, and that future work is needed to explore aerosolization mechanisms and taxon‐specific aerosolization rates. Our study is a first step toward understanding the production of bioaerosols in extreme environments dominated by microbial life.
1 aTrout‐Haney, Jessica, V.1 aHeindel, Ruth, C1 aVirginia, Ross, A. uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/1758-2229.1283202639nas a2200301 4500008004100000245008400041210006900125260001200194520169800206653001501904653002101919653002401940653002701964653001301991100002102004700002602025700001702051700001602068700002502084700002502109700001702134700002202151700002302173700002002196700002402216700002402240856007302264 2019 eng d00aThe hydroecology of an ephemeral wetland in the McMurdo Dry Valleys, Antarctica0 ahydroecology of an ephemeral wetland in the McMurdo Dry Valleys c11/20193 aThe McMurdo Dry Valleys (MDV) is a polar desert on the coast of East Antarctica where ephemeral wetlands become hydrologically active during warm and sunny summers when sub‐surface flows are generated from melting snowfields. To understand the structure and function of polar wetland ecosystems, we investigated the hydroecology of one such wetland, the Wormherder Creek wetland, during the warm and sunny summer of 2008 – 2009, when the wetland was hydrologically reactivated. Conservative tracer (LiCl) was injected for a 2‐hour period into a stream above the wetland to determine flow path orientations and hydrologic residence times. Tracer results indicated that surface water is rapidly exchanged with wetland groundwater and wetland residence times may exceed two austral summers. Major ion concentrations were uniform in samples from surface water and shallow groundwater throughout the wetland. Microbial mats in the wetland had high autotrophic index values (the ratios of chlorophyll a [Chl‐a]/ash‐free dry mass [AFDM]), ranging from 9‐38 μg Chl‐a/mg AFDM, indicative of actively photosynthesizing mat communities. The diatom communities in the mats were relatively uniform compared to those in mats from regularly flowing MDV streams, with four endemic and one widespread diatom taxa of the genus Luticola accounting for an average of 86% of the community. These results indicate that the hydrologic characteristics of the wetland contribute to uniform geochemical conditions. In turn, uniform geochemical conditions may explain the high autotrophic index values of the microbial mats and relatively low spatial variation of the diatom community.
10aAntarctica10adesert hydrology10adiatom biodiversity10ahyporheic interactions10awetlands1 aWlostowski, Adam1 aSchulte, Nicholas, O.1 aAdams, Byron1 aBall, Becky1 aEsposito, Rhea, M.M.1 aGooseff, Michael, N.1 aLyons, Berry1 aNielsen, Uffe, N.1 aVirginia, Ross, A.1 aWall, Diana, H.1 aWelch, Kathleen, A.1 aMcKnight, Diane, M. uhttps://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JG00515301888nas a2200301 4500008004100000245004500041210004100086260001200127300001300139490000600152520103800158100001501196700002301211700002801234700002401262700002201286700002501308700001401333700002301347700002401370700002201394700002001416700002601436700001601462700002301478700001601501856006901517 2019 eng d00aThe polar regions in a 2°C warmer world0 apolar regions in a 2°C warmer world c12/2019 aeaaw98830 v53 aOver the past decade, the Arctic has warmed by 0.75°C, far outpacing the global average, while Antarctic tem- peratures have remained comparatively stable. As Earth approaches 2°C warming, the Arctic and Antarctic may reach 4°C and 2°C mean annual warming, and 7°C and 3°C winter warming, respectively. Expected consequences of increased Arctic warming include ongoing loss of land and sea ice, threats to wildlife and traditional human livelihoods, increased methane emissions, and extreme weather at lower latitudes. With low biodiversity, Antarctic ecosystems may be vulnerable to state shifts and species invasions. Land ice loss in both regions will contribute substantially to global sea level rise, with up to 3 m rise possible if certain thresholds are crossed. Mitigation efforts can slow or reduce warming, but without them northern high latitude warming may accelerate in the next two to four decades. International cooperation will be crucial to foreseeing and adapting to expected changes.
1 aPost, Eric1 aAlley, Richard, B.1 aChristensen, Torben, R.1 aMacias-Fauria, Marc1 aForbes, Bruce, C.1 aGooseff, Michael, N.1 aIler, Amy1 aKerby, Jeffrey, T.1 aLaidre, Kristin, L.1 aMann, Michael, E.1 aOlofsson, Johan1 aStroeve, Julienne, C.1 aUlmer, Fran1 aVirginia, Ross, A.1 aWang, Muyin uhttp://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aaw988302347nas a2200193 4500008004100000022001300041245009200054210006900146260001200215300001200227490000800239520173400247100002101981700001702002700001502019700002402034700002302058856007202081 2018 eng d a0016706100aBiogeochemical weathering of soil apatite grains in the McMurdo Dry Valleys, Antarctica0 aBiogeochemical weathering of soil apatite grains in the McMurdo c01/2018 a136-1450 v3203 aThe biogeochemical weathering of the mineral apatite links the lithosphere to the biosphere by releasing the essential nutrient phosphorus (P) into the soil ecosystem. In Taylor Valley, Antarctica, faster rates of apatite weathering may be responsible for the higher concentrations of bioavailable soil P that exist in the Fryxell Basin as compared to the Bonney Basin. In this study, we use scanning electron microscopy to quantify the morphology and surface etching of individual apatite grains to determine whether the degree of apatite weathering differs between the Fryxell and Bonney Basins as well as saturated and dry soil sediments. We show that apatite grains from the Fryxell Basin are rounder, have fewer intact crystal faces, and are more chemically etched than grains from the Bonney Basin. In the Bonney Basin, apatite grains from dry soils show few signs of chemical dissolution, suggesting that soil moisture is a stronger control on the rate of apatite weathering in the Bonney Basin than in the Fryxell Basin. In addition, etch-pit morphologies in the Bonney Basin are more clearly controlled by the hexagonal crystal structure of apatite, while in the Fryxell Basin, etch pits demonstrate a wide range of morphologies without clear crystallographic control. Higher rates of apatite weathering in the Fryxell Basin may be due to the legacy of the physical abrasion of apatite grains during transport by a warm-based ice sheet, as well as the higher levels of precipitation and soil moisture closer to the coast. Our grain-scale approach provides a new perspective on P cycling in the McMurdo Dry Valleys and has implications for apatite weathering and P dynamics in the early stages of soil development.
1 aHeindel, Ruth, C1 aLyons, Berry1 aWelch, Sue1 aSpickard, Angela, M1 aVirginia, Ross, A. uhttps://www.sciencedirect.com/science/article/pii/S001670611732069402670nas a2200181 4500008004100000245011700041210006900158260001200227300001400239490000700253520207300260100002602333700001702359700002202376700002302398700002002421856004702441 2018 eng d00aObserved trends of soil fauna in the Antarctic Dry Valleys: early signs of shifts predicted under climate change0 aObserved trends of soil fauna in the Antarctic Dry Valleys early c02/2018 a312 - 3210 v993 aLong-term observations of ecological communities are necessary for generating and testing predictions of ecosystem responses to climate change. We investigated temporal trends and spatial patterns of soil fauna along similar environmental gradients in three sites of the McMurdo Dry Valleys, Antarctica, spanning two distinct climatic phases: a decadal cool- ing trend from the early 1990s through the austral summer of February 2001, followed by a shift to the current trend of warming summers and more frequent discrete warming events. After February 2001, we observed a decline in the dominant species (the nematode Scottnema lindsayae) and increased abundance and expanded distribution of less common taxa (rotifers, tardigrades, and other nematode species). Such diverging responses have resulted in slightly greater evenness and spatial homogeneity of taxa. However, total abundance of soil fauna appears to be declining, as positive trends of the less common species so far have not compen- sated for the declining numbers of the dominant species. Interannual variation in the propor- tion of juveniles in the dominant species was consistent across sites, whereas trends in abundance varied more. Structural equation modeling supports the hypothesis that the observed biological trends arose from dissimilar responses by dominant and less common spe- cies to pulses of water availability resulting from enhanced ice melt. No direct effects of mean summer temperature were found, but there is evidence of indirect effects via its weak but signif- icant positive relationship with soil moisture. Our findings show that combining an under- standing of species responses to environmental change with long-term observations in the field can provide a context for validating and refining predictions of ecological trends in the abun- dance and diversity of soil fauna.
1 aAndriuzzi, Walter, S.1 aAdams, Byron1 aBarrett, John, E.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttp://doi.wiley.com/10.1002/ecy.2090/full02340nas a2200181 4500008004100000022001300041245009000054210006900144260001200213490000800225520176100233100001601994700001702010700002202027700002002049700002302069856006602092 2018 eng d a0038071700aSoil biological responses to C, N and P fertilization in a polar desert of Antarctica0 aSoil biological responses to C N and P fertilization in a polar c07/20180 v1223 a
In the polar desert ecosystem of the McMurdo Dry Valleys of Antarctica, biology is constrained by available liquid water, low temperatures, as well as the availability of organic matter and nutrient elements. These soil ecosystems are climate-sensitive, where projected future warming may have profound effects on biological communities and biogeochemical cycling. Warmer temperatures will mobilize meltwater from permafrost and glaciers, may increase precipitation and may be accompanied by pulses of nutrient availability. Enhanced water and nutrient availability have the potential to greatly influence desert soil biology and ecosystem processes. The objectives of this 5-year study were to determine which nutrient elements (C, N, P) are most limiting to dry valley soil communities and whether landscape history (i.e., in situ soil type and stoichiometry) influences soil community response to nutrient additions. After 3 years of no noticeable response, soil CO2 flux was significantly higher under addition of C+ N than the other treatments, regardless of in situ soil stoichiometry, but microbial biomass and invertebrate abundance were variable and not influenced in the same manner. A stable isotope incubation suggests that fertilization increases C and N mineralization from organic matter via stimulating microbial activity, with loss of both the applied treatments as well in situ C and N. However, these responses are relatively short-lived, suggesting long-term impacts on C and N cycling would only occur if meltwater and nutrient pulses are sustained over time, a scenario that is increasingly likely for the dry valleys.
1 aBall, Becky1 aAdams, Byron1 aBarrett, John, E.1 aWall, Diana, H.1 aVirginia, Ross, A. uhttp://linkinghub.elsevier.com/retrieve/pii/S003807171830108102332nas a2200193 4500008004100000245017900041210006900220260001200289300001600301490000700317520164300324100001701967700001701984700002202001700001702023700002302040700002002063856005502083 2018 eng d00aStable C and N isotope ratios reveal soil food web structure and identify the nematode Eudorylaimus antarcticus as an omnivore–predator in Taylor Valley, Antarctica0 aStable C and N isotope ratios reveal soil food web structure and c05/2018 a1013–10180 v413 a
Soil food webs of the McMurdo Dry Valleys, Antarctica are simple. These include primary trophic levels of mosses, algae, cyanobacteria, bacteria, archaea, and fungi, and their protozoan and metazoan consumers (including relatively few species of nematodes, tardigrades, rotifers, and microarthropods). These biota are patchily distributed across the landscape, with greatest faunal biodiversity associated with wet soil. Understanding trophic structure is critical to studies of biotic interactions and distribution; yet, McMurdo Dry Valley soil food web structure has been inferred from limited laboratory culturing and micro- scopic observations. To address this, we measured stable isotope natural abundance ratios of C (13C/12C) and N (15N/14N) for di erent metazoan taxa (using whole body biomass) to determine soil food web structure in Taylor Valley, Antarctica. Nitrogen isotopes were most useful in di erentiating trophic levels because they fractionated predictably at higher trophic levels. Using 15N/14N, we found that three trophic levels were present in wet soil habitats. While cyanobacterial mats were the primary trophic level, the nematode Plectus murrayi, tardigrade Acutuncus antarcticus, and rotifers composed a secondary trophic level of grazers. Eudorylaimus antarcticus had a 15N/14N ratio that was 2–4‰ higher than that of grazers, indicating that this species is the sole member of a tertiary trophic level. Understanding the trophic positions of soil fauna is critical to predictions of current and future species interactions and their distributions for the McMurdo Dry Valleys, Antarctica.
1 aShaw, Ashley1 aAdams, Byron1 aBarrett, John, E.1 aLyons, Berry1 aVirginia, Ross, A.1 aWall, Diana, H. uhttp://link.springer.com/10.1007/s00300-017-2243-802975nas a2200289 4500008004100000245013500041210006900176260001200245490000600257520199400263653002902257653002302286653002402309653003102333653002602364653002602390100002602416700002402442700001602466700002002482700002202502700002602524700002502550700002302575700001702598856007002615 2018 eng d00aStoichiometric Shifts in Soil C:N:P Promote Bacterial Taxa Dominance, Maintain Biodiversity, and Deconstruct Community Assemblages0 aStoichiometric Shifts in Soil CNP Promote Bacterial Taxa Dominan c07/20180 v93 aImbalances in C:N:P supply ratios may cause bacterial resource limitations and constrain biogeochemical processes, but the importance of shifts in soil stoichiometry are complicated by the nearly limitless interactions between an immensely rich species pool and a multiple chemical resource forms. To more clearly identify the impact of soil C:N:P on bacteria, we evaluated the cumulative effects of single and coupled long-term nutrient additions (i.e., C as mannitol, N as equal concentrations NH4 + and NO3 − , and P as Na3PO4) and water on communities in an Antarctic polar desert, Taylor Valley. Untreated soils possessed relatively low bacterial diversity, simplified organic C sources due to the absence of plants, limited inorganic N, and excess soil P potentially attenuating links between C:N:P. After 6 years of adding resources, an alleviation of C and N colimitation allowed one rare Micrococcaceae, an Arthrobacter species, to dominate, comprising 47% of the total community abundance and elevating soil respiration by 136% relative to untreated soils. The addition of N alone reduced C:N ratios, elevated bacterial richness and diversity, and allowed rare taxa relying on ammonium and nitrite for metabolism to become more abundant [e.g., nitrite oxidizing Nitrospira species (Nitrosomonadaceae), denitrifiers utilizing nitrite (Gemmatimonadaceae) and members of Rhodobacteraceae with a high affinity for ammonium]. Based on community co-occurrence networks, lower C:P ratios in soils following P and CP additions created more diffuse and less connected communities by disrupting 73% of species interactions and selecting for taxa potentially exploiting abundant P. Unlike amended nutrients, water additions alone elicited no lasting impact on communities. Our results suggest that as soils become nutrient rich a wide array of outcomes are possible from species dominance and the deconstruction of species interconnectedness to the maintenance of biodiversity.
10aecological stoichiometry10aLake Fryxell Basin10aMcMurdo Dry Valleys10anetwork community modeling10anutrient colimitation10aSolirubrobacteriaceae1 aAanderud, Zachary, T.1 aSaurey, Sabrina, D.1 aBall, Becky1 aWall, Diana, H.1 aBarrett, John, E.1 aMuscarella, Mario, E.1 aGriffin, Natasha, A.1 aVirginia, Ross, A.1 aAdams, Byron uhttps://www.frontiersin.org/article/10.3389/fmicb.2018.01401/full00851nas a2200265 4500008004100000245009100041210006900132260001200201300001400213490000600227100002500233700002200258700001700280700002100297700002400318700001700342700002400359700002100383700002000404700003300424700003100457700002300488700002000511856005400531 2017 eng d00aDecadal ecosystem response to an anomalous melt season in a polar desert in Antarctica0 aDecadal ecosystem response to an anomalous melt season in a pola c09/2017 a1334-13380 v11 aGooseff, Michael, N.1 aBarrett, John, E.1 aAdams, Byron1 aDoran, Peter, T.1 aFountain, Andrew, G1 aLyons, Berry1 aMcKnight, Diane, M.1 aPriscu, John, C.1 aSokol, Eric, R.1 aTakacs-Vesbach, Cristina, D.1 aVandegehuchte, Martijn, L.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://www.nature.com/articles/s41559-017-0253-000535nas a2200145 4500008004100000245008700041210006900128260001200197300001200209490000700221100002100228700002400249700002300273856009300296 2017 eng d00aLandscape-scale soil phosphorus variability in the McMurdo Dry Valleys, Antarctica0 aLandscapescale soil phosphorus variability in the McMurdo Dry Va c06/2017 a252-2630 v291 aHeindel, Ruth, C1 aSpickard, Angela, M1 aVirginia, Ross, A. uhttps://www.cambridge.org/core/product/identifier/S0954102016000742/type/journal_article01797nas a2200253 4500008004100000022001400041245007900055210006900134260001200203300001400215490000700229520101000236100002401246700001601270700001701286700002101303700002001324700002501344700002201369700002101391700002801412700002301440856008001463 2016 eng d a0006-356800aThe Impact of a Large-Scale Climate Event on Antarctic Ecosystem Processes0 aImpact of a LargeScale Climate Event on Antarctic Ecosystem Proc c10/2016 a848 - 8630 v663 aExtreme climate and weather events, such as a drought, hurricanes, or ice storms, can strongly imprint ecosystem processing and may alter ecosystem structure. Ecosystems in extreme environments are particularly vulnerable because of their adaptation to severe limitations in energy, water, or nutrients. The vulnerability can be expressed as a relatively long-lasting ecosystem response to a small or brief change in environmental conditions. Such an event occurred in Antarctica and affected two vastly different ecosystems: a marine-dominated coastal system and a terrestrial polar desert. Both sites experienced winds that warmed air temperatures above the 0°C threshold, resulting in extensive snow and ice melt and triggering a series of cascading effects through the ecosystems that are continuing to play out more than a decade later. This highlights the sensitivity of Antarctic ecosystems to warming events, which should occur more frequently in the future with global climate warming.
1 aFountain, Andrew, G1 aSaba, Grace1 aAdams, Byron1 aDoran, Peter, T.1 aFraser, William1 aGooseff, Michael, N.1 aObryk, Maciek, K.1 aPriscu, John, C.1 aStammerjohn, Sharon, E.1 aVirginia, Ross, A. uhttp://academic.oup.com/bioscience/article-pdf/66/10/848/7510601/biw110.pdf00658nas a2200193 4500008004100000022001400041245011300055210007100168260001200239300001400251490000700265100001800272700002000290700002300310700003100333700001900364700001700383856006400400 2016 eng d a0722-406000aImpact of diurnal freeze–thaw cycles on the soil nematode Scottnema lindsayae in Taylor Valley, Antarctica0 aImpact of diurnal freeze–thaw cycles on the soil nematode Scottn c04/2016 a583 - 5920 v391 aKnox, Matthew1 aWall, Diana, H.1 aVirginia, Ross, A.1 aVandegehuchte, Martijn, L.1 aSan Gil, Inigo1 aAdams, Byron uhttps://link.springer.com/article/10.1007/s00300-015-1809-604455nas a2200121 4500008004100000245007900041210006900120260001200189520398300201100001604184700002304200856011004223 2015 eng d00aControls on diel soil CO2 flux across moisture gradients in a polar desert0 aControls on diel soil CO2 flux across moisture gradients in a po c06/20153 aThe McMurdo Dry Valleys of Antarctica are a climate-sensitive ecosystem, where future projected climate warming will increase liquid water availability to release soil biology from physical limitations and alter ecosystem processes. For example, many studies have shown that CO2 flux, an important aspect of the carbon cycle, is controlled by temperature and moisture, which often overwhelm biotic contributions in desert ecosystems. However, these studies used either single-point measurements during peak times of biological activity or diel cycles at individual locations. Here, we present diel cycles of CO2 flux from a range of soil moisture conditions and a variety of locations and habitats to determine how diel cycles of CO2 flux vary across gradients of wet-to-dry soil and whether the water source influences the diel cycle of moist soil. Soil temperature, water content and microbial biomass significantly influenced CO2 flux. Soil temperature explained most of the variation. Soil CO2 flux moderately increased with microbial biomass, demonstrating a sometimes small but significant role of biological fluxes. Our results show that over gradients of soil moisture, both geochemical and biological fluxes contribute to soil CO2 flux, and physical factors must be considered when estimating biological CO2 flux in systems with low microbial biomass.
1 aBall, Becky1 aVirginia, Ross, A. uhttp://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9776001&fileId=S095410201500025501657nas a2200229 4500008004100000245008700041210006900128260001600197300000900213490000600222520097300228100002201201700001401223700001601237700002301253700001701276700002201293700002101315700002201336700001401358856005501372 2015 eng d00aDeep groundwater and potential subsurface habitats beneath an Antarctic dry valley0 aDeep groundwater and potential subsurface habitats beneath an An cApr-04-2017 a68310 v63 aThe occurrence of groundwater in Antarctica, particularly in the ice-free regions and along the coastal margins is poorly understood. Here we use an airborne transient electromagnetic (AEM) sensor to produce extensive imagery of resistivity beneath Taylor Valley. Regional-scale zones of low subsurface resistivity were detected that are inconsistent with the high resistivity of glacier ice or dry permafrost in this region. We interpret these results as an indication that liquid, with sufficiently high solute content, exists at temperatures well below freezing and considered within the range suitable for microbial life. These inferred brines are widespread within permafrost and extend below glaciers and lakes. One system emanates from below Taylor Glacier into Lake Bonney and a second system connects the ocean with the eastern 18 km of the valley. A connection between these two basins was not detected to the depth limitation of the AEM survey (~350 m).1 aMikucki, Jill, A.1 aAuken, E.1 aTulaczyk, S1 aVirginia, Ross, A.1 aSchamper, C.1 aSørensen, K., I.1 aDoran, Peter, T.1 aDugan, Hilary, A.1 aFoley, N. uhttp://www.nature.com/doifinder/10.1038/ncomms783100571nas a2200181 4500008004100000022001400041245008700055210006900142260001200211300001200223490000800235100001700243700002000260700002300280700001600303700001800319856005200337 2014 eng d a1313-298900aEcological Biogeography of the Terrestrial Nematodes of Victoria Land, Antarctica0 aEcological Biogeography of the Terrestrial Nematodes of Victoria c06/2015 a29 - 710 v4191 aAdams, Byron1 aWall, Diana, H.1 aVirginia, Ross, A.1 aBroos, Emma1 aKnox, Matthew uhttp://zookeys.pensoft.net/articles.php?id=389900505nas a2200133 4500008004100000245012800041210006900169260001200238300001200250490000700262100001600269700002300285856006300308 2014 eng d00aThe ecological role of moss in a polar desert: implications for aboveground- belowground and terrestrial -aquatic linkages.0 aecological role of moss in a polar desert implications for above c04/2014 a651-6640 v371 aBall, Becky1 aVirginia, Ross, A. uhttp://link.springer.com/article/10.1007/s00300-014-1465-200428nas a2200109 4500008004100000245009200041210006900133260001200202100001600214700002300230856006500253 2014 eng d00aMicrobial biomass and respiration responses to nitrogen fertilization in a polar desert0 aMicrobial biomass and respiration responses to nitrogen fertiliz c01/20141 aBall, Becky1 aVirginia, Ross, A. uhttp://link.springer.com/article/10.1007%2Fs00300-014-1459-000646nas a2200193 4500008004100000245007700041210006900118260001100187300001400198490001200212100002100224700002100245700002400266700002400290700002000314700002300334700002400357856007100381 2012 eng d00aAeolian flux of biotic and abiotic material in Taylor Valley, Antarctica0 aAeolian flux of biotic and abiotic material in Taylor Valley Ant c6/2012 a102 - 1110 v155-1561 aŠabacká, Marie1 aPriscu, John, C.1 aBasagic, Hassan, J.1 aFountain, Andrew, G1 aWall, Diana, H.1 aVirginia, Ross, A.1 aGreenwood, Mark, C. uhttp://www.sciencedirect.com/science/article/pii/S0169555X1100622200640nas a2200193 4500008004100000245010100041210006900142260001200211300001000223490000600233100002200239700002000261700001700281700002300298700001600321700002500337700002400362856006000386 2012 eng d00aThe ecology of pulse events: insights from an extreme climatic event in a polar desert ecosystem0 aecology of pulse events insights from an extreme climatic event c02/2012 aart170 v31 aNielsen, Uffe, N.1 aWall, Diana, H.1 aAdams, Byron1 aVirginia, Ross, A.1 aBall, Becky1 aGooseff, Michael, N.1 aMcKnight, Diane, M. uhttp://www.esajournals.org/doi/abs/10.1890/ES11-00325.100548nas a2200133 4500008004100000245010500041210006900146260001200215300001400227490001200241100001600253700002300269856012200292 2012 eng d00aMeltwater seep patches increase heterogeneity of soil geochemistry and therefore habitat suitability0 aMeltwater seep patches increase heterogeneity of soil geochemist c11/2012 a652 - 6600 v189-1901 aBall, Becky1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/meltwater-seep-patches-increase-heterogeneity-soil-geochemistry-and-therefore-habitat00626nas a2200181 4500008004100000245012300041210006900164260001100233300001200244490000700256100001600263700002000279700001200299700001700311700002200328700002300350856007100373 2012 eng d00aThawing permafrost alters nematode populations and soil habitat characteristics in an Antarctic polar desert ecosystem0 aThawing permafrost alters nematode populations and soil habitat c3/2012 a75 - 810 v551 aSmith, T.E.1 aWall, Diana, H.1 aHogg, I1 aAdams, Byron1 aNielsen, Uffe, N.1 aVirginia, Ross, A. uhttp://www.sciencedirect.com/science/article/pii/S003140561100115600530nas a2200157 4500008004100000245008700041210006900128260001200197300001600209490000700225100002200232700002000254700001700274700002300291856005800314 2011 eng d00aAntarctic nematode communities: observed and predicted responses to climate change0 aAntarctic nematode communities observed and predicted responses c11/2011 a1701 - 17110 v341 aNielsen, Uffe, N.1 aWall, Diana, H.1 aAdams, Byron1 aVirginia, Ross, A. uhttp://www.springerlink.com/content/v588t5671p1w1323/00609nas a2200169 4500008004100000022001400041245010500055210006900160260001200229490002400241100001600265700002200281700002500303700002300328700002000351856006800371 2011 eng d a0800-039500aImplications of meltwater pulse events for soil biology and biogeochemical cycling in a polar desert0 aImplications of meltwater pulse events for soil biology and biog c12/20110 v30812810303525113401 aBall, Becky1 aBarrett, John, E.1 aGooseff, Michael, N.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttp://www.polarresearch.net/index.php/polar/article/view/1455500632nas a2200181 4500008004100000245008400041210006900125260001100194300001400205490000700219100002200226700002000248700001400268700001700282700001700299700002300316856011100339 2011 eng d00aNematode communities of Byers Peninsula, Livingston Island, maritime Antarctica0 aNematode communities of Byers Peninsula Livingston Island mariti c8/2011 a349 - 3570 v231 aNielsen, Uffe, N.1 aWall, Diana, H.1 aLi, Grace1 aToro, Manuel1 aAdams, Byron1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/nematode-communities-byers-peninsula-livingston-island-maritime-antarctica00756nas a2200205 4500008004100000245011700041210006900158260001100227300001400238490000700252100001800259700002200277700002000299700001700319700002200336700002400358700002300382700002400405856012100429 2010 eng d00aExperimentally increased snow accumulation alters soil moisture and animal community structure in a polar desert0 aExperimentally increased snow accumulation alters soil moisture c7/2010 a897 - 9070 v331 aAyres, Edward1 aNkem, Johnson, N.1 aWall, Diana, H.1 aAdams, Byron1 aBarrett, John, E.1 aSimmons, Breana, L.1 aVirginia, Ross, A.1 aFountain, Andrew, G uhttps://mcm.lternet.edu/content/experimentally-increased-snow-accumulation-alters-soil-moisture-and-animal-community00622nas a2200157 4500008004100000245010300041210006900144300001400213490000700227100001600234700002300250700002200273700002400295700002000319856012500339 2009 eng d00aInteractions between physical and biotic factors influence CO_2 flux in Antarctic dry valley soils0 aInteractions between physical and biotic factors influence CO2 f a1510-15170 v411 aBall, Becky1 aVirginia, Ross, A.1 aBarrett, John, E.1 aParsons, Andrew, N.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/interactions-between-physical-and-biotic-factors-influence-co2-flux-antarctic-dry-valley00654nas a2200169 4500008004100000245010800041210006900149300001400218490000700232100002400239700002000263700001700283700001800300700002200318700002300340856012100363 2009 eng d00aLong-term experimental warming reduces soil nematode populations in the McMurdo Dry Valleys, Antarctica0 aLongterm experimental warming reduces soil nematode populations a2052-20600 v411 aSimmons, Breana, L.1 aWall, Diana, H.1 aAdams, Byron1 aAyres, Edward1 aBarrett, John, E.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/long-term-experimental-warming-reduces-soil-nematode-populations-mcmurdo-dry-valleys00629nas a2200169 4500008004100000245008900041210006900130300001400199490000700213100002400220700002000244700001700264700001800281700002200299700002300321856011500344 2009 eng d00aTerrestrial mesofauna in above- and below-ground habitats: Taylor Valley, Antarctica0 aTerrestrial mesofauna in above and belowground habitats Taylor V a1549-15580 v321 aSimmons, Breana, L.1 aWall, Diana, H.1 aAdams, Byron1 aAyres, Edward1 aBarrett, John, E.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/terrestrial-mesofauna-above-and-below-ground-habitats-taylor-valley-antarctica00606nas a2200145 4500008004100000245011900041210006900160300001400229490000700243100002200250700002300272700002000295700001700315856012800332 2008 eng d00aDecline in a dominant invertebrate species contributes to altered carbon cycling in a low-diversity soil ecosystem0 aDecline in a dominant invertebrate species contributes to altere a1734-17440 v141 aBarrett, John, E.1 aVirginia, Ross, A.1 aWall, Diana, H.1 aAdams, Byron uhttps://mcm.lternet.edu/content/decline-dominant-invertebrate-species-contributes-altered-carbon-cycling-low-diversity-soil02709nas a2200241 4500008004100000245010000041210006900141260001200210300001400222490000700236520190500243100001802148700002202166700002002188700001702208700002202225700001302247700002402260700002202284700002402306700002302330856011402353 2008 eng d00aEffects of Human Trampling on Populations of Soil Fauna in the McMurdo Dry Valleys, Antarctica.0 aEffects of Human Trampling on Populations of Soil Fauna in the M c12/2008 a1544-15510 v223 aAntarctic ecosystems are often considered nearly pristine because levels of anthropogenic disturbance are extremely low there. Nevertheless, over recent decades there has been a rapid increase in the number of people, researchers and tourists, visiting Antarctica. We evaluated, over 10 years, the direct impact of foot traffic on the abundance of soil animals and soil properties in Taylor Valley within the McMurdo Dry Valleys region of Antarctica. We compared soils from minimally disturbed areas with soils from nearby paths that received intermediate and high levels of human foot traffic (i.e., up to approximately 80 passes per year). The nematodes Scottnema lindsayae and Eudorylaimus sp. were the most commonly found animal species, whereas rotifers and tardigrades were found only occasionally. On the highly trampled footpaths, abundance of S. lindsayae and Eudorylaimus sp. was up to 52 and 76% lower, respectively, than in untrampled areas. Moreover, reduction in S. lindsayae abundance was more pronounced after 10 years than 2 years and in the surface soil than in the deeper soil, presumably because of the longer period of disturbance and the greater level of physical disturbance experienced by the surface soil. The ratio of living to dead Eudorylaimus sp. also declined with increased trampling intensity, which is indicative of increased mortality or reduced fecundity. At one site there was evidence that high levels of trampling reduced soil CO2 fluxes, which is related to total biological activity in the soil. Our results show that even low levels of human traffic can significantly affect soil biota in this ecosystem and may alter ecosystem processes, such as carbon cycling. Consequently, management and conservation plans for Antarctic soils should consider the high sensitivity of soil fauna to physical disturbance as human presence in this ecosystem increases.
1 aAyres, Edward1 aNkem, Johnson, N.1 aWall, Diana, H.1 aAdams, Byron1 aBarrett, John, E.1 aBroos, E1 aParsons, Andrew, N.1 aPowers, Laura, E.1 aSimmons, Breana, L.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/effects-human-trampling-populations-soil-fauna-mcmurdo-dry-valleys-antarctica00591nas a2200157 4500008004100000245009700041210006900138260001200207300001200219490000700231100001300238700002200251700002300273700002000296856011700316 2008 eng d00aThe influence of soil geochemistry on nematode distribution, McMurdo Dry Valleys, Antarctica0 ainfluence of soil geochemistry on nematode distribution McMurdo c02/2008 a119-1280 v401 aPoage, M1 aBarrett, John, E.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/influence-soil-geochemistry-nematode-distribution-mcmurdo-dry-valleys-antarctica00595nas a2200169 4500008004100000245008100041210006900122260001200191300001400203490000700217653002100224653001400245100002200259700002300281700002000304856010100324 2008 eng d00aPersistent effects of a discrete climate event on a polar desert ecosystem0 aPersistent effects of a discrete climate event on a polar desert c06/2008 a2249-22610 v1410aClimate Response10anematodes1 aBarrett, John, E.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/persistent-effects-discrete-climate-event-polar-desert-ecosystem00475nas a2200145 4500008004100000245005700041210005700098300001000155490000800165100001500173700002200188700001300210700002300223856008300246 2008 eng d00aSoil phosphorus cycling in an Antarctic polar desert0 aSoil phosphorus cycling in an Antarctic polar desert a21-320 v1441 aBate, Brad1 aBarrett, John, E.1 aPoage, M1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/soil-phosphorus-cycling-antarctic-polar-desert03147nas a2200241 4500008004100000245006800041210006800109260001200177300001400189490000800203520239000211653001102601100002202612700002302634700001702657700002402674700002102698700002402719700002002743700002402763700002102787856009702808 2007 eng d00aBiogeochemical stoichiometry of Antarctic Dry Valley ecosystems0 aBiogeochemical stoichiometry of Antarctic Dry Valley ecosystems c02/2007 aG01010+120 v1123 aAmong aquatic and terrestrial landscapes of the McMurdo Dry Valleys, Antarctica, ecosystem stoichiometry ranges from values near the Redfield ratios for C:N:P to nutrient concentrations in proportions far above or below ratios necessary to support balanced microbial growth. This polar desert provides an opportunity to evaluate stoichiometric approaches to understand nutrient cycling in an ecosystem where biological diversity and activity are low, and controls over the movement and mass balances of nutrients operate over 10–106 years. The simple organisms (microbial and metazoan) comprising dry valley foodwebs adhere to strict biochemical requirements in the composition of their biomass, and when activated by availability of liquid water, they influence the chemical composition of their environment according to these ratios. Nitrogen and phosphorus varied significantly in terrestrial and aquatic ecosystems occurring on landscape surfaces across a wide range of exposure ages, indicating strong influences of landscape development and geochemistry on nutrient availability. Biota control the elemental ratio of stream waters, while geochemical stoichiometry (e.g., weathering, atmospheric deposition) evidently limits the distribution of soil invertebrates. We present a conceptual model describing transformations across dry valley landscapes facilitated by exchanges of liquid water and biotic processing of dissolved nutrients. We conclude that contemporary ecosystem stoichiometry of Antarctic Dry Valley soils, glaciers, streams, and lakes results from a combination of extant biological processes superimposed on a legacy of landscape processes and previous climates.
10aBiggie1 aBarrett, John, E.1 aVirginia, Ross, A.1 aLyons, Berry1 aMcKnight, Diane, M.1 aPriscu, John, C.1 aFountain, Andrew, G1 aWall, Diana, H.1 aMoorhead, Daryl, L.1 aDoran, Peter, T. uhttps://mcm.lternet.edu/content/biogeochemical-stoichiometry-antarctic-dry-valley-ecosystems00499nas a2200121 4500008004100000245007700041210006900118260003100187490000900218100002400227700002300251856010300274 2007 eng d00aEcotoxicity and microbial biogeochemistry of Fluoride in Antarctic soils0 aEcotoxicity and microbial biogeochemistry of Fluoride in Antarct bDartmouth Collegec07/20070 vB.S.1 aCollins, Pamela, M.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/ecotoxicity-and-microbial-biogeochemistry-fluoride-antarctic-soils00539nas a2200145 4500008004100000245008300041210006900124300001200193490000700205100001200212700002000224700002000244700002300264856010600287 2007 eng d00aA mathematical model for variation in water-retention curves among sandy soils0 amathematical model for variation in waterretention curves among a427-4360 v191 aHunt, H1 aTreonis, Amy, M1 aWall, Diana, H.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/mathematical-model-variation-water-retention-curves-among-sandy-soils00491nas a2200121 4500008004100000245008300041210006900124260002200193490000900215100001500224700002300239856010700262 2007 eng d00aSoil organic matter sources and quality in the McMurdo Dry Valleys, Antarctica0 aSoil organic matter sources and quality in the McMurdo Dry Valle bDartmouth College0 vM.S.1 aBate, Brad1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/soil-organic-matter-sources-and-quality-mcmurdo-dry-valleys-antarctica00578nas a2200133 4500008004100000245011000041210006900151100001800220700002000238700001700258700002200275700002300297856012400320 2007 eng d00aUnique similarity of faunal communities across aquatic terrestrial interfaces in a polar desert ecosystem0 aUnique similarity of faunal communities across aquatic terrestri1 aAyres, Edward1 aWall, Diana, H.1 aAdams, Byron1 aBarrett, John, E.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/unique-similarity-faunal-communities-across-aquatic-terrestrial-interfaces-polar-desert00429nas a2200145 4500008004100000245003300041210003200074260003000106300001200136490000600148100002200154700002300176700002000199856006400219 2006 eng d00aBiogeochemistry, terrestrial0 aBiogeochemistry terrestrial aNew YorkbRoutledge Press a154-1550 v11 aBarrett, John, E.1 aVirginia, Ross, A.1 aRiffenburgh, B. uhttps://mcm.lternet.edu/content/biogeochemistry-terrestrial00757nas a2200181 4500008004100000245010900041210006900150300001200219490000700231100002200238700002300260700002000283700001900303700001700322700001400339700001600353856020600369 2006 eng d00aCo-variation in soil biodiversity and biogeochemistry in Northern and Southern Victoria Land, Antarctica0 aCovariation in soil biodiversity and biogeochemistry in Northern a535-5480 v181 aBarrett, John, E.1 aVirginia, Ross, A.1 aWall, Diana, H.1 aCary, Craig, S1 aAdams, Byron1 aHacker, A1 aAislabie, J uhttps://www.cambridge.org/core/journals/antarctic-science/article/covariation-in-soil-biodiversity-and-biogeochemistry-in-northern-and-southern-victoria-land-antarctica/C3514C28DB75F3A19DB5F266D4B1B56E00612nas a2200145 4500008004100000245011000041210006900151260003400220300001100254100001300265700001700278700002200295700002300317856012600340 2006 eng d00aPedogenic carbonate distribution within glacial till in Taylor Valley, Southern Victoria Land, Antarctica0 aPedogenic carbonate distribution within glacial till in Taylor V bGeological Society of America a89-1031 aFoley, K1 aLyons, Berry1 aBarrett, John, E.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/pedogenic-carbonate-distribution-within-glacial-till-taylor-valley-southern-victoria-land00554nas a2200169 4500008004100000245006300041210006200104300001200166490000700178100001500185700001600200700002200216700002000238700002300258700001500281856008800296 2006 eng d00aPhosphorus fractions in soils of Taylor Valley, Antarctica0 aPhosphorus fractions in soils of Taylor Valley Antarctica a806-8150 v701 aBlecker, S1 aIppolito, J1 aBarrett, John, E.1 aWall, Diana, H.1 aVirginia, Ross, A.1 aNorvell, K uhttps://mcm.lternet.edu/content/phosphorus-fractions-soils-taylor-valley-antarctica00583nas a2200157 4500008004100000245008700041210006900128300001200197490000700209100002200216700002300238700002200261700002000283700001000303856011200313 2006 eng d00aSalt tolerance and survival thresholds for two species of Antarctic soil nematodes0 aSalt tolerance and survival thresholds for two species of Antarc a643-6510 v291 aNkem, Johnson, N.1 aVirginia, Ross, A.1 aBarrett, John, E.1 aWall, Diana, H.1 aLi, G uhttps://mcm.lternet.edu/content/salt-tolerance-and-survival-thresholds-two-species-antarctic-soil-nematodes00531nas a2200145 4500008004100000245007100041210006900112300001400181490000700195100002200202700002300224700002400247700002000271856009400291 2006 eng d00aSoil carbon turnover model for the McMurdo Dry Valleys, Antarctica0 aSoil carbon turnover model for the McMurdo Dry Valleys Antarctic a3065-30820 v381 aBarrett, John, E.1 aVirginia, Ross, A.1 aParsons, Andrew, N.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/soil-carbon-turnover-model-mcmurdo-dry-valleys-antarctica00506nas a2200121 4500008004100000245008900041210006900130260002200199490000900221100001500230700002300245856011600268 2006 eng d00aSoil nitrogen cycling in cold desert (McMurdo Dry Valleys) and hot desert ecosystems0 aSoil nitrogen cycling in cold desert McMurdo Dry Valleys and hot bDartmouth College0 vM.S.1 aStucker, A1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/soil-nitrogen-cycling-cold-desert-mcmurdo-dry-valleys-and-hot-desert-ecosystems00812nas a2200265 4500008004100000245006500041210006400106300001400170490000700184100002200191700002200213700001500235700001600250700002000266700001900286700002300305700002000328700001600348700001600364700001600380700001600396700001700412700002400429856009300453 2006 eng d00aTerrestrial ecosystem processes of Victoria Land, Antarctica0 aTerrestrial ecosystem processes of Victoria Land Antarctica a3019-30340 v381 aBarrett, John, E.1 aNkem, Johnson, N.1 aSletten, R1 aSteltzer, H1 aWall, Diana, H.1 aWallenstein, M1 aVirginia, Ross, A.1 aHopkins, D., W.1 aAislabie, J1 aBargagli, R1 aBockheim, J1 aCampbell, I1 aLyons, Berry1 aMoorhead, Daryl, L. uhttps://mcm.lternet.edu/content/terrestrial-ecosystem-processes-victoria-land-antarctica02560nas a2200205 4500008004100000245008000041210006900121300001200190490000700202520193000209653001102139100002202150700002002172700002302192700002202215700001302237700001802250700001702268856006902285 2006 eng d00aWind dispersal of soil invertebrates in the McMurdo Dry Valleys, Antarctica0 aWind dispersal of soil invertebrates in the McMurdo Dry Valleys a346-3520 v293 aDispersal of soil organisms is crucial for their spatial distribution and adaptation to the prevailing conditions of the Antarctic Dry Valleys. This study investigated the possibility of wind dispersal of soil invertebrates within the dry valleys. Soil invertebrates were evaluated in (1) pockets of transported sediments to lake ice and glacier surfaces, (2) wind-transported dust particles in collection pans (Bundt pans) 100 cm above the soil surface, and (3) sediments transported closer to the surface (<50 cm) and collected in open top chambers (OTCs). Invertebrates were extracted and identified. Nematodes were identified to species and classified according to life stage and sex. Three species of nematodes were recovered and Scottnema lindsayae was the most dominant. There were more juveniles (∼71%) in the transported sediments than adults (29%). Tardigrades and rotifers were more abundant in sediments on lake and glacier surfaces while nematodes were more abundant in the dry sediment collections of Bundt pans and OTCs. The abundance of immobile (dead) nematodes in the Bundt pans and OTCs was three times greater than active (live) nematodes. Anhydrobiosis constitutes a survival mechanism that allows wind dispersal of nematodes in the McMurdo Dry Valleys. Our results show that soil invertebrates are dispersed by wind in the Dry Valleys and are viable in ice communities on lake surfaces and glaciers.
10aBiggie1 aNkem, Johnson, N.1 aWall, Diana, H.1 aVirginia, Ross, A.1 aBarrett, John, E.1 aBroos, E1 aPorazinska, D1 aAdams, Byron uhttp://link.springer.com/content/pdf/10.1007%2Fs00300-005-0061-x00884nas a2200265 4500008004100000245007800041210007000119300001100189490000700200653002500207100002100232700001900253700002700272700002700299700002400326700002100350700001700371700001300388700002400401700002400425700002400449700002300473700002000496856010200516 2005 eng d00aComment on ``El Niño suppresses Antarctic warming'' by N. Bertler et al.0 aComment on El Niño suppresses Antarctic warming by N Bertler et aL077060 v3210aTropical meteorology1 aDoran, Peter, T.1 aClow, Gary, D.1 aFritsen, Christian, H.1 aMcKay, Christopher, P.1 aParsons, Andrew, N.1 aPriscu, John, C.1 aLyons, Berry1 aWalsh, J1 aFountain, Andrew, G1 aMcKnight, Diane, M.1 aMoorhead, Daryl, L.1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/comment-el-ni%C3%B1o-suppresses-antarctic-warming-n-bertler-et-al00519nas a2200133 4500008004100000245008900041210006900130300001200199490000700211100001600218700002000234700002300254856010800277 2005 eng d00aDistribution and diversity of soil protozoa in the McMurdo Dry Valleys of Antarctica0 aDistribution and diversity of soil protozoa in the McMurdo Dry V a756-7620 v281 aBamforth, S1 aWall, Diana, H.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/distribution-and-diversity-soil-protozoa-mcmurdo-dry-valleys-antarctica00711nas a2200205 4500008004100000245008900041210006900130300001200199490000700211100001700218700002400235700002000259700002000279700002300299700002400322700002100346700001400367700001500381856010900396 2005 eng d00aGroundwater seeps in Taylor Valley Antarctica: An example of a subsurface melt event0 aGroundwater seeps in Taylor Valley Antarctica An example of a su a200-2060 v401 aLyons, Berry1 aWelch, Kathleen, A.1 aCarey, Anne, E.1 aWall, Diana, H.1 aVirginia, Ross, A.1 aFountain, Andrew, G1 aDoran, Peter, T.1 aCsatho, B1 aTremper, C uhttps://mcm.lternet.edu/content/groundwater-seeps-taylor-valley-antarctica-example-subsurface-melt-event00476nas a2200133 4500008004100000245006400041210006400105300001000169490000700179100002000186700002000206700002300226856009300249 2005 eng d00aInvertebrate diversity in Taylor Valley soils and sediments0 aInvertebrate diversity in Taylor Valley soils and sediments a13-160 v331 aTreonis, Amy, M1 aWall, Diana, H.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/invertebrate-diversity-taylor-valley-soils-and-sediments00875nas a2200361 4500008004100000245001800041210001800059260001700077300001200094100001900106700001500125700001500140700002300155700001300178700001300191700001900204700001500223700001400238700002000252700001500272700001400287700001700301700001800318700001900336700001400355700002200369700001400391700001500405700001500420700001600435700001200451856005000463 2005 eng d00aPolar Systems0 aPolar Systems bIsland Press a717-7431 aChapin, F., S.1 aMcGuire, A1 aNuttall, M1 aVirginia, Ross, A.1 aYoung, O1 aZimov, S1 aChristensen, T1 aGodduhn, A1 aMurphy, E1 aWall, Diana, H.1 aZockler, C1 aBerman, M1 aCallaghan, T1 aConvey, Peter1 aCrepin, A., S.1 aDanell, K1 aDucklow, Hugh, W.1 aForbes, B1 aKofinas, G1 aHassan, R.1 aScholes, R.1 aAsh, N. uhttps://mcm.lternet.edu/content/polar-systems02635nas a2200181 4500008004100000245007200041210006900113260001200182300001200194490000700206520208100213653001102294100002202305700002302327700002402350700002002374856005902394 2005 eng d00aPotential soil organic matter turnover in Taylor Valley, Antarctica0 aPotential soil organic matter turnover in Taylor Valley Antarcti c02/2005 a108-1170 v373 aAntarctic Dry Valley ecosystems are among the most inhospitable soil ecosystems on earth with simple food webs and nearly undetectable fluxes of carbon (C) and nitrogen (N). Due to the lack of vascular plants, soil organic matter concentrations are extremely low, and it is unclear how much of the contemporary soil C budget is actively cycling or a legacy of paleolake production and sedimentation. While recent work indicates multiple sources of organic matter for dry valley soils, the composition and kinetics of organic pools remain poorly characterized. We examined soil organic matter pools and potential C and N turnover in soils from within six sites located across three hydrological basins of Taylor Valley, Antarctica that differed in surface age, microclimate and proximity to legacy (paleolake) sources of organic matter. We estimated potential C and N mineralization, and rate kinetics using gas exchange and repeated leaching techniques during 90-d incubations of surface soils collected from valley basin and valley slope positions in three basins of Taylor Valley. Soil organic C content was negatively correlated with the ages of underlying tills, supporting previous descriptions of legacy organic matter. Carbon and N mineralization generally followed 1st order kinetics and were well described by exponential models. Labile pools of C (90 d) were 10% of the total organic C in the upper 5 cm of the soil profile. Labile N was 50% of the total N in surface soils of Taylor Valley. These results show that a large proportion of soil C and particularly N are mineralizable under suitable conditions and suggest that a kinetically defined labile pool of organic matter is potentially active in the field during brief intervals of favorable microclimate. Climate variation changing the duration of these conditions may have potentially large effects on the small pools of C and N in these soils.
10aBiggie1 aBarrett, John, E.1 aVirginia, Ross, A.1 aParsons, Andrew, N.1 aWall, Diana, H. uhttp://instaar.metapress.com/content/e653225425230175/00655nas a2200169 4500008004100000245010600041210006900147300001000216490000700226100001800233700002400251700002200275700002000297700002300317700002000340856012500360 2004 eng d00aThe Biodiversity and Biogeochemistry of Cryoconite Holes from McMurdo Dry Valley Glaciers, Antarctica0 aBiodiversity and Biogeochemistry of Cryoconite Holes from McMurd a84-910 v361 aPorazinska, D1 aFountain, Andrew, G1 aNylen, Thomas, H.1 aTranter, Martyn1 aVirginia, Ross, A.1 aWall, Diana, H. uhttps://mcm.lternet.edu/content/biodiversity-and-biogeochemistry-cryoconite-holes-mcmurdo-dry-valley-glaciers-antarctica00504nas a2200145 4500008004100000245006100041210006100102300001200163490000600175100002400181700002200205700002000227700002300247856008800270 2004 eng d00aSoil carbon dioxide flux from Antarctic Dry Valley soils0 aSoil carbon dioxide flux from Antarctic Dry Valley soils a286-2950 v71 aParsons, Andrew, N.1 aBarrett, John, E.1 aWall, Diana, H.1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/soil-carbon-dioxide-flux-antarctic-dry-valley-soils00433nas a2200121 4500008004100000245005800041210005700099260002200156490000900178100001500187700002300202856008600225 2004 eng d00aSoil phosphorus dynamics in Taylor Valley, Antarctica0 aSoil phosphorus dynamics in Taylor Valley Antarctica bDartmouth College0 vB.S.1 aBate, Brad1 aVirginia, Ross, A. uhttps://mcm.lternet.edu/content/soil-phosphorus-dynamics-taylor-valley-antarctica02593nas a2200181 4500008004100000245009500041210006900136300001400205490000700219520193100226100002202157700002302179700002002202700002402222700002202246700002402268856011902292 2004 eng d00aVariation in biogeochemistry and soil biodiversity across spatial scales in a polar desert0 aVariation in biogeochemistry and soil biodiversity across spatia a3105-31180 v853 a