<?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%">Dragone, Nicholas B.</style></author><author><style face="normal" font="default" size="100%">Melisa A. Diaz</style></author><author><style face="normal" font="default" size="100%">Hogg, Ian D.</style></author><author><style face="normal" font="default" size="100%">W. Berry Lyons</style></author><author><style face="normal" font="default" size="100%">W. Andrew Jackson</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">Adams, Byron J.</style></author><author><style face="normal" font="default" size="100%">Noah Fierer</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Exploring the boundaries of microbial habitability in soil</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><keywords><keyword><style  face="normal" font="default" size="100%">Antarctica</style></keyword><keyword><style  face="normal" font="default" size="100%">astrobiology</style></keyword><keyword><style  face="normal" font="default" size="100%">bacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">extremophiles</style></keyword><keyword><style  face="normal" font="default" size="100%">fungi</style></keyword><keyword><style  face="normal" font="default" size="100%">soils</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2021</style></year><pub-dates><date><style  face="normal" font="default" size="100%">06/2021</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JG006052</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">126</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Microbes are widely assumed to be capable of colonizing even the most challenging terrestrial surface environments on Earth given enough time. We would not expect to find surface soils uninhabited by microbes as soils typically harbor diverse microbial communities and viable microbes have been detected in soils exposed to even the most inhospitable conditions. However, if uninhabited soils do exist, we might expect to find them in Antarctica. We analyzed 204 ice-free soils collected from across a remote valley in the Transantarctic Mountains (84&amp;ndash;85&amp;deg;S, 174&amp;ndash;177&amp;deg;W) and were able to identify a potential limit of microbial habitability. While most of the soils we tested contained diverse microbial communities, with fungi being particularly ubiquitous, microbes could not be detected in many of the driest, higher elevation soils&amp;mdash;results that were confirmed using cultivation-dependent, cultivation-independent, and metabolic assays. While we cannot confirm that this subset of soils is completely sterile and devoid of microbial life, our results suggest that microbial life is severely restricted in the coldest, driest, and saltiest Antarctic soils. Constant exposure to these conditions for thousands of years has limited microbial communities so that their presence and activity is below detectable limits using a variety of standard methods. Such soils are unlikely to be unique to the studied region with this work supporting previous hypotheses that microbial habitability is constrained by near-continuous exposure to cold, dry, and salty conditions, establishing the environmental conditions that limit microbial life in terrestrial surface soils.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">6</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%">Diana H. Wall</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Biotic interactions in experimental Antarctic soil microcosms vary with abiotic stress</style></title><secondary-title><style face="normal" font="default" size="100%">Soil Systems</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">bacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">biological interactions</style></keyword><keyword><style  face="normal" font="default" size="100%">desert</style></keyword><keyword><style  face="normal" font="default" size="100%">nematode</style></keyword><keyword><style  face="normal" font="default" size="100%">polar</style></keyword><keyword><style  face="normal" font="default" size="100%">soil communities</style></keyword><keyword><style  face="normal" font="default" size="100%">top-down effects</style></keyword><keyword><style  face="normal" font="default" size="100%">trophic interactions</style></keyword></keywords><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.mdpi.com/2571-8789/3/3/57</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">3</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Biotic interactions structure ecological communities but abiotic factors affect the strength of these relationships. These interactions are difficult to study in soils due to their vast biodiversity and the many environmental factors that affect soil species. The McMurdo Dry Valleys (MDV), Antarctica, are relatively simple soil ecosystems compared to temperate soils, making them an excellent study system for the trophic relationships of soil. Soil microbes and relatively few species of nematodes, rotifers, tardigrades, springtails, and mites are patchily distributed across the cold, dry landscape, which lacks vascular plants and terrestrial vertebrates. However, glacier and permafrost melt are expected to cause shifts in soil moisture and solutes across this ecosystem. To test how increased moisture and salinity affect soil invertebrates and their biotic interactions, we established a laboratory microcosm experiment (4 community &amp;times; 2 moisture &amp;times; 2 salinity treatments). Community treatments were: (1) Bacteria only (control), (2) Scottnema (&lt;em&gt;S. lindsayae&lt;/em&gt; + bacteria), (3) Eudorylaimus (&lt;em&gt;E. antarcticus&lt;/em&gt; + bacteria), and (4) Mixed (&lt;em&gt;S. lindsayae&lt;/em&gt; + &lt;em&gt;E. antarcticus&lt;/em&gt; + bacteria). Salinity and moisture treatments were control and high. High moisture reduced &lt;em&gt;S. lindsayae&lt;/em&gt; adults, while high salinity reduced the total &lt;em&gt;S. lindsayae&lt;/em&gt; population. We found that &lt;em&gt;S. lindsayae&lt;/em&gt; exerted top-down control over soil bacteria populations, but this effect was dependent on salinity treatment. In the high salinity treatment, bacteria were released from top-down pressure as &lt;em&gt;S. lindsayae&lt;/em&gt; declined. Ours was the first study to empirically demonstrate, although in lab microcosm conditions, top-down control in the MDV soil food web.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue></record></records></xml>