%0 Journal Article %J Science of The Total Environment %D 2022 %T Organic matter distribution in the icy environments of Taylor Valley, Antarctica %A Guo, Bixi %A Li, Wei %A Santibáñez, Pamela %A John C. Priscu %A Liu, Yongqin %A Liu, Keshao %K Antarctica %K bacteria %K ice cores %K katabatic wind %K marine aerosol %K organic matter %X

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.

%B Science of The Total Environment %V 841 %P 156639 %8 10/2022 %G eng %U https://www.sciencedirect.com/science/article/abs/pii/S0048969722037366 %R 10.1016/j.scitotenv.2022.156639 %0 Journal Article %J Ecology %D 2018 %T Observed trends of soil fauna in the Antarctic Dry Valleys: early signs of shifts predicted under climate change %A Andriuzzi, Walter S. %A Byron Adams %A John E. Barrett %A Ross A. Virginia %A Diana H. Wall %X

Long-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. 

%B Ecology %V 99 %P 312 - 321 %8 02/2018 %G eng %U http://doi.wiley.com/10.1002/ecy.2090/full %N 2 %! Ecology %R 10.1002/ecy.2090 %0 Journal Article %J Organic Geochemistry %D 2010 %T Origin and tentative identification of tri to pentaunsaturated ketones in sediments from Lake Fryxell, East Antarctica %A Jaraula, Caroline M.B. %A Brassell, Simon C. %A Rachael M. Morgan-Kiss %A Peter T. Doran %A Kenig, Fabien %B Organic Geochemistry %V 41 %P 386 - 397 %8 4/2010 %G eng %N 4 %R 10.1016/j.orggeochem.2009.12.004 %0 Book Section %B Polar Lakes and Rivers: Limnology of Arctic and Antarctic Aquatic Ecosystems %D 2008 %T Origin and geomorphology of lakes in the polar regions %A Pienitz, R %A Peter T. Doran %A Lamoureuz, S %E Warwick F. Vincent %E Johanna Laybourn-Parry %B Polar Lakes and Rivers: Limnology of Arctic and Antarctic Aquatic Ecosystems %I Oxford University Press %C Oxford %G eng %R LTER %0 Journal Article %J Geophysical Research Letters %D 2007 %T Organic carbon in Antarctic precipitation %A W. Berry Lyons %A Kathleen A. Welch %A Doggett, J %B Geophysical Research Letters %V 34 %G eng %R LTER %0 Journal Article %J Annals of Glaciology %D 2005 %T The origin of channels on lower Taylor Glacier, McMurdo Dry Valleys Antarctica and their implication for water runoff %A Johnston, R %A Andrew G Fountain %A Thomas H. Nylen %B Annals of Glaciology %V 40 %P 1-7 %G eng %R LTER %0 Journal Article %J Microbial Ecology %D 2004 %T The Occurrence of Lysogenic Bacteria and Microbial Aggregates in the Lakes of the McMurdo Dry Valleys, Antarctica %A John T. Lisle %A John C. Priscu %B Microbial Ecology %V 47 %P 427-439 %G eng %N 4 %M LTER63373 %0 Journal Article %J Polar Biology %D 2003 %T Organic matter and soil biota of upland wetlands in Taylor Valley, Antarctica %A Daryl L. Moorhead %A John E. Barrett %A Ross A. Virginia %A Diana H. Wall %A Porazinska, D %B Polar Biology %V 26 %P 1009-1019 %G eng %M LTER49867 %0 Journal Article %J Global Change Biology %D 2001 %T Organic carbon cycling in Taylor Valley, Antarctica: Quantifying soil reservoirs and soil respiration %A Melody B. Burkins %A Ross A. Virginia %A Diana H. Wall %B Global Change Biology %V 7 %P 113-125 %G eng %M LTER49822 %0 Journal Article %J Ecology %D 2000 %T The Origin of Soil Organic Matter in Taylor Valley, Antarctica: A Legacy of Climate Change %A Melody B. Burkins %A Ross A. Virginia %A C. Page Chamberlain %A Diana H. Wall %K legacy %B Ecology %V 81 %P 2377-2391 %G eng %M LTER49819 %0 Book Section %B Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica %D 1998 %T Optical Properties of the McMurdo Dry Valley Lakes, Antarctica %A Clive Howard-Williams %A Anne-Maree Schwarz %A Ian Hawes %A John C. Priscu %B Ecosystem Processes in a Polar Desert: The McMurdo Dry Valleys, Antarctica %S Antarctic Research Series %V 72 %P 189-203 %G eng %M LTER12858 %0 Journal Article %J Global Change Biology %D 1997 %T Open-top Designs for Manipulating Field Temperature in High-Latitude Ecosystems %A G. M. Marion %A G.H.R. Henry %A Diana W. Freckman %A J. Johnstone %A G. Jones %A M.H. Jones %A E. Levesque %A U. Molau %A P. MØLGAARD %A Andrew N. Parsons %A J. Svoboda %A Ross A. Virginia %B Global Change Biology %V 3 %P 20-32 %8 12/1997 %G eng %N S1 %M LTER12889 %R 10.1111/j.1365-2486.1997.gcb136.x