<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Lemoine, Nathan P.</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">Melisa A. Diaz</style></author><author><style face="normal" font="default" size="100%">Dragone, Nicholas B.</style></author><author><style face="normal" font="default" size="100%">Franco, André L. C.</style></author><author><style face="normal" font="default" size="100%">Noah Fierer</style></author><author><style face="normal" font="default" size="100%">W. Berry Lyons</style></author><author><style face="normal" font="default" size="100%">Hogg, Ian D.</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Lurgi, Miguel</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Strong dispersal limitation of microbial communities at Shackleton Glacier, Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">mSystems</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">community assembly</style></keyword><keyword><style  face="normal" font="default" size="100%">determinism</style></keyword><keyword><style  face="normal" font="default" size="100%">dispersal</style></keyword><keyword><style  face="normal" font="default" size="100%">niche</style></keyword><keyword><style  face="normal" font="default" size="100%">stochasticity</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2023</style></year><pub-dates><date><style  face="normal" font="default" size="100%">01/2023</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://journals.asm.org/doi/full/10.1128/msystems.01254-22</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">8</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Microbial communities can be structured by both deterministic and stochastic processes, but the relative importance of these processes remains unknown. The ambiguity partly arises from an inability to disentangle soil microbial processes from confounding factors, such as aboveground plant communities or anthropogenic disturbance. In this study, we characterized the relative contributions of determinism and stochasticity to assembly processes of soil bacterial communities across a large environmental gradient of undisturbed Antarctic soils. We hypothesized that harsh soils would impose a strong environmental selection on microbial communities, whereas communities in benign soils would be structured largely by dispersal. Contrary to our expectations, dispersal was the dominant assembly mechanism across the entire soil environmental gradient, including benign environments. The microbial community composition reflects slowly changing soil conditions and dispersal limitation of isolated sites. Thus, stochastic processes, as opposed to deterministic, are primary drivers of soil ecosystem assembly across space at our study site. This is especially surprising given the strong environmental constraints on soil microorganisms in one of the harshest environments on the planet, suggesting that dispersal could be a driving force in microbial community assembly in soils worldwide.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Thompson, Andrew R.</style></author><author><style face="normal" font="default" size="100%">Geisen, Stefan</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Shotgun metagenomics reveal a diverse assemblage of protists in a model Antarctic soil ecosystem</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental Microbiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Antarctica</style></keyword><keyword><style  face="normal" font="default" size="100%">extremophiles</style></keyword><keyword><style  face="normal" font="default" size="100%">functional groups</style></keyword><keyword><style  face="normal" font="default" size="100%">metagenomics</style></keyword><keyword><style  face="normal" font="default" size="100%">protozoa</style></keyword><keyword><style  face="normal" font="default" size="100%">soil microbiology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2020</style></year><pub-dates><date><style  face="normal" font="default" size="100%">08/2020</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://sfamjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1462-2920.15198</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The soils of the McMurdo Dry Valleys (MDV) of Antarctica are established models for understanding fundamental processes in soil ecosystem functioning (e.g. ecological tipping points, community structuring, and nutrient cycling) because the extreme physical environment drastically reduces biodiversity and ecological complexity. Understanding the functioning of MDV soils requires in‐depth knowledge of the diversity of MDV soil species. Protists, which contribute significantly to soil ecosystem functioning worldwide, remain poorly characterized in the MDV. To better assess the diversity of MDV protists, we performed shotgun metagenomics on 18 sites representing a variety of landscape features and edaphic variables. Our results show MDV soil protists are diverse at both the genus (155 of 281 eukaryote genera) and family (120) levels, but comprise only 6% of eukaryotic reads. Protists are structured by moisture, total N, and distance from the local coast, and possess limited richness in arid (&amp;lt;5% moisture) and at high elevation sites, known drivers of communities in the MDV. High relative diversity and broad distribution of protists in our study promotes these organisms as key members of MDV soil microbiomes and the MDV as a useful system for understanding the contribution of soil protists to the structure of soil microbiomes.&lt;/p&gt;</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">van den Hoogen, Johan</style></author><author><style face="normal" font="default" size="100%">Geisen, Stefan</style></author><author><style face="normal" font="default" size="100%">Routh, Devin</style></author><author><style face="normal" font="default" size="100%">Ferris, Howard</style></author><author><style face="normal" font="default" size="100%">Traunspurger, Walter</style></author><author><style face="normal" font="default" size="100%">Wardle, D</style></author><author><style face="normal" font="default" size="100%">de Goede, Ron G. M.</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">Ahmad, Wasim</style></author><author><style face="normal" font="default" size="100%">Andriuzzi, Walter S.</style></author><author><style face="normal" font="default" size="100%">Richard D. Bardgett</style></author><author><style face="normal" font="default" size="100%">Bonkowski, Michael</style></author><author><style face="normal" font="default" size="100%">Campos-Herrera, Raquel</style></author><author><style face="normal" font="default" size="100%">Cares, Juvenil E.</style></author><author><style face="normal" font="default" size="100%">Caruso, Tancredi</style></author><author><style face="normal" font="default" size="100%">de Brito Caixeta, Larissa</style></author><author><style face="normal" font="default" size="100%">Chen, Xiaoyun</style></author><author><style face="normal" font="default" size="100%">Costa, Sofia R.</style></author><author><style face="normal" font="default" size="100%">Creamer, Rachel</style></author><author><style face="normal" font="default" size="100%">Mauro da Cunha Castro, José</style></author><author><style face="normal" font="default" size="100%">Dam, Marie</style></author><author><style face="normal" font="default" size="100%">Djigal, Djibril</style></author><author><style face="normal" font="default" size="100%">Escuer, Miguel</style></author><author><style face="normal" font="default" size="100%">Griffiths, Bryan S.</style></author><author><style face="normal" font="default" size="100%">Gutiérrez, Carmen</style></author><author><style face="normal" font="default" size="100%">Hohberg, Karin</style></author><author><style face="normal" font="default" size="100%">Kalinkina, Daria</style></author><author><style face="normal" font="default" size="100%">Kardol, Paul</style></author><author><style face="normal" font="default" size="100%">Kergunteuil, Alan</style></author><author><style face="normal" font="default" size="100%">Korthals, Gerard</style></author><author><style face="normal" font="default" size="100%">Krashevska, Valentyna</style></author><author><style face="normal" font="default" size="100%">Kudrin, Alexey A.</style></author><author><style face="normal" font="default" size="100%">Li, Qi</style></author><author><style face="normal" font="default" size="100%">Liang, Wenju</style></author><author><style face="normal" font="default" size="100%">Magilton, Matthew</style></author><author><style face="normal" font="default" size="100%">Marais, Mariette</style></author><author><style face="normal" font="default" size="100%">Martín, José Antonio Rodríguez</style></author><author><style face="normal" font="default" size="100%">Matveeva, Elizaveta</style></author><author><style face="normal" font="default" size="100%">Mayad, El Hassan</style></author><author><style face="normal" font="default" size="100%">Mulder, Christian</style></author><author><style face="normal" font="default" size="100%">Mullin, Peter</style></author><author><style face="normal" font="default" size="100%">Neilson, Roy</style></author><author><style face="normal" font="default" size="100%">Nguyen, T. A. Duong</style></author><author><style face="normal" font="default" size="100%">Uffe N. Nielsen</style></author><author><style face="normal" font="default" size="100%">Okada, Hiroaki</style></author><author><style face="normal" font="default" size="100%">Rius, Juan Emilio Palomares</style></author><author><style face="normal" font="default" size="100%">Pan, Kaiwen</style></author><author><style face="normal" font="default" size="100%">Peneva, Vlada</style></author><author><style face="normal" font="default" size="100%">Pellissier, Loïc</style></author><author><style face="normal" font="default" size="100%">Carlos Pereira da Silva, Julio</style></author><author><style face="normal" font="default" size="100%">Pitteloud, Camille</style></author><author><style face="normal" font="default" size="100%">Powers, Thomas O.</style></author><author><style face="normal" font="default" size="100%">Powers, Kirsten</style></author><author><style face="normal" font="default" size="100%">Quist, Casper W.</style></author><author><style face="normal" font="default" size="100%">Rasmann, Sergio</style></author><author><style face="normal" font="default" size="100%">Moreno, Sara Sánchez</style></author><author><style face="normal" font="default" size="100%">Scheu, Stefan</style></author><author><style face="normal" font="default" size="100%">Setälä, Heikki</style></author><author><style face="normal" font="default" size="100%">Sushchuk, Anna</style></author><author><style face="normal" font="default" size="100%">Tiunov, Alexei V.</style></author><author><style face="normal" font="default" size="100%">Trap, Jean</style></author><author><style face="normal" font="default" size="100%">van der Putten, W</style></author><author><style face="normal" font="default" size="100%">Vestergård, Mette</style></author><author><style face="normal" font="default" size="100%">Villenave, Cecile</style></author><author><style face="normal" font="default" size="100%">Waeyenberge, Lieven</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">Wilschut, Rutger</style></author><author><style face="normal" font="default" size="100%">Wright, Daniel G.</style></author><author><style face="normal" font="default" size="100%">Yang, Jiue-in</style></author><author><style face="normal" font="default" size="100%">Crowther, Thomas Ward</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil nematode abundance and functional group composition at a global scale</style></title><secondary-title><style face="normal" font="default" size="100%">Nature</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2019</style></year><pub-dates><date><style  face="normal" font="default" size="100%">08/2019</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.nature.com/articles/s41586-019-1418-6</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">572</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, few quantitative, spatially explicit models of the active belowground community currently exist. In particular, nematodes are the most abundant animals on Earth, filling all trophic levels in the soil food web. Here we use 6,759 georeferenced samples to generate a mechanistic understanding of the patterns of the global abundance of nematodes in the soil and the composition of their functional groups. The resulting maps show that 4.4 &amp;plusmn; 0.64 &amp;times; 10&lt;sup&gt;20&lt;/sup&gt; nematodes (with a total biomass of approximately 0.3 gigatonnes) inhabit surface soils across the world, with higher abundances in sub-Arctic regions (38% of total) than in temperate (24%) or tropical (21%) regions. Regional variations in these global trends also provide insights into local patterns of soil fertility and functioning. These high-resolution models provide the first steps towards representing soil ecological processes in global biogeochemical models and will enable the prediction of elemental cycling under current and future climate scenarios.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">7768</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ball, Becky</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">Ross A. Virginia</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil biological responses to C, N and P fertilization in a polar desert of Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">Soil Biology and Biochemistry</style></secondary-title><short-title><style face="normal" font="default" size="100%">Soil Biology and Biochemistry</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">2018</style></year><pub-dates><date><style  face="normal" font="default" size="100%">07/2018</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0038071718301081</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">122</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;div title=&quot;Page 1&quot;&gt;&lt;div&gt;&lt;div&gt;&lt;p&gt;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.,&amp;nbsp;in situ&amp;nbsp;soil type and stoichiometry) influences soil community response to nutrient additions. After 3 years of no noticeable response, soil CO2&amp;nbsp;flux was significantly higher under addition of C+ N than the other treatments, regardless of&amp;nbsp;in situ&amp;nbsp;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&amp;nbsp;in situ&amp;nbsp;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.&lt;/p&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;p&gt;&amp;nbsp;&lt;/p&gt;</style></abstract><section><style face="normal" font="default" size="100%">7</style></section></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wlostowski, Adam</style></author><author><style face="normal" font="default" size="100%">Michael N. Gooseff</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil Moisture Controls the Thermal Habitat of Active Layer Soils in the McMurdo Dry Valleys, Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Geophysical Research: Biogeosciences</style></secondary-title><short-title><style face="normal" font="default" size="100%">J. Geophys. Res. Biogeosci.</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">2018</style></year><pub-dates><date><style  face="normal" font="default" size="100%">01/2018</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017JG004018</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">123</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Antarctic soil ecosystems are strongly controlled by abiotic habitat variables. Regional climate change in the McMurdo Dry Valleys is expected to cause warming over the next century, leading to an increase in frequency of freeze-thaw cycling in the soil habitat. Previous studies show that physiological stress associated with freeze-thaw cycling adversely affects invertebrate populations by decreasing abundance and positively selecting for larger body sizes. However, it remains unclear whether or not climate warming will indeed enhance the frequency of annual freeze-thaw cycling and associated physiological stresses. This research quantifies the frequency, rate, and spatial heterogeneity of active layer freezing to better understand how regional climate change may affect active layer soil thermodynamics, and, in turn, affect soil macroinvertebrate communities. Shallow active layer temperature, specific conductance, and soil moisture were observed along natural wetness gradients. Field observations show that the frequency and rate of freeze events are nonlinearly related to freezable soil moisture (θf). Over a 2 year period, soils at θf &amp;lt; 0.080 m3/m3 experienced between 15 and 35 freeze events and froze rapidly compared to soils with θf &amp;gt; 0.080 m3/m3, which experienced between 2 and 6 freeze events and froze more gradually. A numerical soil thermodynamic model is able to simulate observed freezing rates across a range of θf, reinforcing a well-known causal relationship between soil moisture and active layer freezing dynamics. Findings show that slight increases in soil moisture can potentially offset the effect of climate warming on exacerbating soil freeze-thaw cycling.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><section><style face="normal" font="default" size="100%">46-59</style></section></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Andriuzzi, Walter S.</style></author><author><style face="normal" font="default" size="100%">Lee F. Stanish</style></author><author><style face="normal" font="default" size="100%">Breana L. Simmons</style></author><author><style face="normal" font="default" size="100%">Chris Jaros</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">Diane M. McKnight</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Spatial and temporal patterns of microbial mats and associated invertebrates along an Antarctic stream</style></title><secondary-title><style face="normal" font="default" size="100%">Polar Biology</style></secondary-title><short-title><style face="normal" font="default" size="100%">Polar Biol</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">diatoms</style></keyword><keyword><style  face="normal" font="default" size="100%">Disturbance</style></keyword><keyword><style  face="normal" font="default" size="100%">Dry valleys</style></keyword><keyword><style  face="normal" font="default" size="100%">Epilithon</style></keyword><keyword><style  face="normal" font="default" size="100%">Microfauna</style></keyword><keyword><style  face="normal" font="default" size="100%">Stream flow</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2018</style></year><pub-dates><date><style  face="normal" font="default" size="100%">10/2018</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.springer.com/10.1007/s00300-018-2331-4</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">1911–1921</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;div title=&quot;Page 1&quot;&gt;&lt;div&gt;&lt;div&gt;&lt;div&gt;&lt;p&gt;Microbial biofilms are biological hotspots in many alpine and polar ecosystems, but the controls on and functional significance of their fauna are little known. We studied cyanobacterial mats and the underlying sediment in a glacial meltwater stream in the McMurdo Dry Valleys, Antarctica. We investigated mat biomass (total and phototrophic), diatoms, and micro-meiofauna (nematodes, rotifers, and tardigrades) at nine sites along a 1670 m stream reach in a cold, low-flow growing season, and in a warmer growing season in which peak flows (above 100 L s&amp;minus;1) scoured the mats. Diatom and invertebrate communities were not related, but mat biomass in the low-flow year was negatively related to nematode abundance, including that of the omnivore&amp;nbsp;Eudorylaimus. In the high-flow year that followed, invertebrate abundance was reduced in the mats, diatom community structure was altered, and mat biomass was higher. The difference in invertebrate abundance between years was greater in mats in upstream reaches, where the greatest increases in flow velocity may have occurred, and was negligible in mats in downstream reaches as well as in the sediment beneath the mats. Integrating our results with previous findings, we generate two predictive hypotheses to be tested in glacial meltwater streams: (1) under peak flows invertebrates decline in the microbial mats, while (2) the sediment beneath the mats is a refuge from the flow disturbance. Our results also suggest that, under stable flow conditions, microinvertebrate grazers could exert top-down control on microbial mat biomass.&lt;/p&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;p&gt;&amp;nbsp;&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">10</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Shaw, E. Ashley</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">W. Berry Lyons</style></author><author><style face="normal" font="default" size="100%">Ross A. Virginia</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Stable C and N isotope ratios reveal soil food web structure and identify the nematode &lt;I&gt;Eudorylaimus antarcticus&lt;/I&gt; as an omnivore–predator in Taylor Valley, Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">Polar Biology</style></secondary-title><short-title><style face="normal" font="default" size="100%">Polar Biol</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">2018</style></year><pub-dates><date><style  face="normal" font="default" size="100%">05/2018</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.springer.com/10.1007/s00300-017-2243-8</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">1013–1018</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;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&amp;ndash;4&amp;permil; 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.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">5</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Aanderud, Zachary T.</style></author><author><style face="normal" font="default" size="100%">Saurey, Sabrina D.</style></author><author><style face="normal" font="default" size="100%">Ball, Becky</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Muscarella, Mario E.</style></author><author><style face="normal" font="default" size="100%">Griffin, Natasha A.</style></author><author><style face="normal" font="default" size="100%">Ross A. Virginia</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Stoichiometric Shifts in Soil C:N:P Promote Bacterial Taxa Dominance, Maintain Biodiversity, and Deconstruct Community Assemblages</style></title><secondary-title><style face="normal" font="default" size="100%">Frontiers in Microbiology</style></secondary-title><short-title><style face="normal" font="default" size="100%">Front. Microbiol.</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">ecological stoichiometry</style></keyword><keyword><style  face="normal" font="default" size="100%">Lake Fryxell Basin</style></keyword><keyword><style  face="normal" font="default" size="100%">McMurdo Dry Valleys</style></keyword><keyword><style  face="normal" font="default" size="100%">network community modeling</style></keyword><keyword><style  face="normal" font="default" size="100%">nutrient colimitation</style></keyword><keyword><style  face="normal" font="default" size="100%">Solirubrobacteriaceae</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2018</style></year><pub-dates><date><style  face="normal" font="default" size="100%">07/2018</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.frontiersin.org/article/10.3389/fmicb.2018.01401/full</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">9</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Imbalances 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 &amp;minus; , 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.&lt;/p&gt;</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">Gozel, U</style></author><author><style face="normal" font="default" size="100%">Dillman, A</style></author><author><style face="normal" font="default" size="100%">Chaston, J</style></author><author><style face="normal" font="default" size="100%">Hogg, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The southernmost worm, Scottnema lindsayae (Nematoda): diversity, dispersal and ecological stability.</style></title><secondary-title><style face="normal" font="default" size="100%">Polar Biology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><volume><style face="normal" font="default" size="100%">30</style></volume><pages><style face="normal" font="default" size="100%">809-815</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">D. W. Hopkins</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A synthesis of soil biodiversity and ecosystem functioning in Victoria Land, Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">Soil Biology and Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><volume><style face="normal" font="default" size="100%">38</style></volume><pages><style face="normal" font="default" size="100%">3001-3002</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></record></records></xml>