<?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>Armin J. Howell</dc:contributor>
  <dc:contributor>Robin H. Reibold</dc:contributor>
  <dc:contributor>Theresa A. McHugh</dc:contributor>
  <dc:contributor>Mackenzie A. Eickhoff</dc:contributor>
  <dc:contributor>Sasha C. Reed</dc:contributor>
  <dc:creator>Terry J. Torres-Cruz</dc:creator>
  <dc:date>2018</dc:date>
  <dc:description>&lt;div id="ASec1" class="AbstractSection"&gt;&lt;p class="Heading"&gt;&lt;strong&gt;Background and aim&lt;/strong&gt;&lt;/p&gt;&lt;p id="Par1" class="Para"&gt;Biological soil crusts (biocrusts) play numerous crucial roles in drylands, which comprise over 40% of Earth’s terrestrial surface. Among these key contributions is the fixation of atmospheric nitrogen. Yet, relatively little is known about the N&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;fixation capabilities of different lichen species that are found in late successional biocrust communities across drylands globally.&lt;/p&gt;&lt;/div&gt;&lt;div id="ASec2" class="AbstractSection"&gt;&lt;p class="Heading"&gt;&lt;strong&gt;Methods&lt;/strong&gt;&lt;/p&gt;&lt;p id="Par2" class="Para"&gt;In order to improve our species-specific understanding of biocrust lichen N&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;fixation, we collected biocrusts dominated by four common species of lichens –&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Collema&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;spp.,&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Gyalolechia desertorum&lt;/i&gt;,&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Psora decipiens&lt;/i&gt;, and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Squamarina lentigera&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;– that represent a range of lichen families and morphological types. Nitrogenase activity of the biocrust community dominated by these lichens was evaluated using the acetylene reduction assay. Additionally, biocrust community composition was assessed using the point-intercept method along transects at varied distances from exposed bedrock.&lt;/p&gt;&lt;/div&gt;&lt;div id="ASec3" class="AbstractSection"&gt;&lt;p class="Heading"&gt;&lt;strong&gt;Results&lt;/strong&gt;&lt;/p&gt;&lt;p id="Par3" class="Para"&gt;As expected,&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Collema&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;spp.-dominated biocrusts had the highest rates of nitrogenase activity, with rates up to seven times larger than those of the other three target species. Nitrogen concentrations and carbon:nitrogen ratios of lichen tissue differed among lichen species. However, when the composite biocrust profile was assessed (i.e., biocrust tissue, microbial cells, and mineral soil to a 2&amp;nbsp;cm depth) these among-species differences in total nitrogen disappeared. Community composition changed according to distance from exposed bedrock, with a higher diversity of lichens closer to the bedrock.&lt;/p&gt;&lt;/div&gt;&lt;div id="ASec4" class="AbstractSection"&gt;&lt;p class="Heading"&gt;&lt;strong&gt;Conclusion&lt;/strong&gt;&lt;/p&gt;&lt;p id="Par4" class="Para"&gt;Multiple drivers, including climate and land use change, affect biocrust community composition and species-specific functional information, even within a group such as late successional biocrusts, could help in forecasting the potential effects of global change on N&lt;sub&gt;2&lt;/sub&gt;fixation, and consequently, soil fertility in drylands.&lt;/p&gt;&lt;/div&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1007/s11104-018-3580-2</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Springer</dc:publisher>
  <dc:title>Species-specific nitrogenase activity in lichen-dominated biological soil crusts from the Colorado Plateau, USA</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>