<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>Benjamin Harlow</dc:contributor>
  <dc:contributor>Cheryl R. Kuske</dc:contributor>
  <dc:contributor>Jayne Belnap</dc:contributor>
  <dc:contributor>R. Dave Evans</dc:contributor>
  <dc:creator>Akihiro Koyama</dc:creator>
  <dc:date>2018</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;We investigated how properties of&amp;nbsp;soil organic matter&amp;nbsp;(SOM) were altered after 10 years exposure to elevated atmospheric CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;concentration ([CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;]) in a Mojave Desert ecosystem, using plant and microbial biomarkers. We focused on roles of&amp;nbsp;&lt;/span&gt;&lt;span&gt;&lt;i&gt;Larrea tridentata&lt;/i&gt;&lt;/span&gt;&lt;span&gt;, the dominant evergreen shrub which form islands of fertility, and&amp;nbsp;biological soil crusts&amp;nbsp;which have extensive cover in plant interspace. Soils to 5 cm in depth were collected under&amp;nbsp;&lt;/span&gt;&lt;i&gt;L. tridentata&lt;/i&gt;&lt;span&gt;&amp;nbsp;and plant interspace, and biological soil crusts to 0.5 cm in depth under three cover types,&amp;nbsp;&lt;/span&gt;&lt;i&gt;Pleuraphis rigida&lt;/i&gt;&lt;span&gt;, a C&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;grass, shrubs and plant interspace.&amp;nbsp;Soil organic carboncontents were not significantly different between elevated and ambient [CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;]. However, significantly higher abundance of&amp;nbsp;&lt;/span&gt;&lt;i&gt;n&lt;/i&gt;&lt;span&gt;-alkanes, a major constituent of foliage wax material, occurred in the elevated compared to ambient [CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;] plots in the soils collected under&amp;nbsp;&lt;/span&gt;&lt;i&gt;L. tridentata&lt;/i&gt;&lt;span&gt;, but no such difference was found in the soils at plant interspace or the biological soil crusts. There was no significant difference in abundance of microbial&amp;nbsp;phospholipid&amp;nbsp;fatty acids between the CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;treatments in the soils of either cover types. However, neutral lipid fatty acid abundance was significantly higher under elevated than ambient [CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;] in the soils under&amp;nbsp;&lt;/span&gt;&lt;i&gt;L. tridentata&lt;/i&gt;&lt;span&gt;, whereas no such significant difference was observed at plant interspace. These results emphasize important roles of the dominant shrubs in SOM formation under elevated [CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;] in arid ecosystems. Elevated [CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;] stimulated growth of&amp;nbsp;&lt;/span&gt;&lt;i&gt;L. tridentata&lt;/i&gt;&lt;span&gt;&amp;nbsp;in wet years, and aboveground litter deposition via senescence contributed to SOM formation in islands of fertility. In addition, elevated [CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;] stimulated soil microbial turnover rates in&amp;nbsp;rhizosphere&amp;nbsp;of&amp;nbsp;&lt;/span&gt;&lt;i&gt;L. tridentata&lt;/i&gt;&lt;span&gt;, which left more soil microbial necromass, a major SOM source. We concluded that responses of dominant shrubs to elevated [CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;] can stimulate SOM formation in arid ecosystems, but biological soil crusts may have limited capacity.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/j.soilbio.2018.01.033</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Plant and microbial biomarkers suggest mechanisms of soil organic carbon accumulation in a Mojave Desert ecosystem under elevated CO2</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>