<?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%">Robinson, Colin Michael</style></author><author><style face="normal" font="default" size="100%">Hansen, Lee D.</style></author><author><style face="normal" font="default" size="100%">Xue, Xia</style></author><author><style face="normal" font="default" size="100%">Adams, Byron J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Temperature response of metabolic activity of an Antarctic nematode</style></title><secondary-title><style face="normal" font="default" size="100%">Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Antarctica</style></keyword><keyword><style  face="normal" font="default" size="100%">carbon cycling</style></keyword><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">nematode</style></keyword><keyword><style  face="normal" font="default" size="100%">respiration rates</style></keyword><keyword><style  face="normal" font="default" size="100%">soil temperature</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://www.mdpi.com/2079-7737/12/1/109</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">12</style></volume><pages><style face="normal" font="default" size="100%">109</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Because of climate change, the McMurdo Dry Valleys of Antarctica (MCM) have experienced an increase in the frequency and magnitude of summer pulse warming and surface ice and snow melting events. In response to these environmental changes, some nematode species in the MCM have experienced steady population declines over the last three decades, but &lt;i&gt;Plectus murrayi&lt;/i&gt;, a mesophilic nematode species, has responded with a steady increase in range and abundance. To determine how &lt;i&gt;P. murrayi&lt;/i&gt; responds to increasing temperatures, we measured metabolic heat and CO&lt;sub&gt;2&lt;/sub&gt; production rates and calculated O&lt;sub&gt;2&lt;/sub&gt; consumption rates as a function of temperature at 5 &amp;deg;C intervals from 5 to 50 &amp;deg;C. Heat, CO&lt;sub&gt;2&lt;/sub&gt; production, and O&lt;sub&gt;2&lt;/sub&gt; consumption rates increase approximately exponentially up to 40 &amp;deg;C, a temperature never experienced in their polar habitat. Metabolic rates decline rapidly above 40 &amp;deg;C and are irreversibly lost at 50 &amp;deg;C due to thermal stress and mortality. &lt;i&gt;Caenorhabditis elegans&lt;/i&gt;, a much more widespread nematode that is found in more temperate environments reaches peak metabolic heat rate at just 27 &amp;deg;C, above which it experiences high mortality due to thermal stress. At temperatures from 10 to 40 &amp;deg;C, &lt;i&gt;P. murrayi&lt;/i&gt; produces about 6 times more CO&lt;sub&gt;2&lt;/sub&gt; than the O&lt;sub&gt;2&lt;/sub&gt; it consumes, a respiratory quotient indicative of either acetogenesis or de novo lipogenesis. No potential acetogenic microbes were identified in the &lt;i&gt;P. murrayi&lt;/i&gt; microbiome, suggesting that &lt;i&gt;P. murrayi&lt;/i&gt; is producing increased CO&lt;sub&gt;2&lt;/sub&gt; as a byproduct of de novo lipogenesis. This phenomenon, in conjunction with increased summer temperatures in their polar habitat, will likely lead to increased demand for carbon and subsequent increases in CO&lt;sub&gt;2&lt;/sub&gt; production, population abundance, and range expansion. If such changes are not concomitant with increased carbon inputs, we predict the MCM soil ecosystems will experience dramatic declines in functional and taxonomic diversity.&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%">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>