<?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>C. C. Treat</dc:contributor>
  <dc:contributor>M. P. Waldrop</dc:contributor>
  <dc:contributor>J. M. Waddington</dc:contributor>
  <dc:contributor>Jennifer W. Harden</dc:contributor>
  <dc:contributor>A. David McGuire</dc:contributor>
  <dc:creator>M. R. Turetsky</dc:creator>
  <dc:date>2008</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Growing season CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;fluxes were monitored over a two year period following the start of ecosystem-scale manipulations of water table position and surface soil temperatures in a moderate rich fen in interior Alaska. The largest CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;fluxes occurred in plots that received both flooding (raised water table position) and soil warming, while the lowest fluxes occurred in unwarmed plots in the lowered water table treatment. A combination of treatment and soil hydroclimate variables explained more than 70% of the variation in ln-transformed CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;fluxes, with mean daily water table position representing the strongest predictor. We used quantitative PCR of the&amp;nbsp;&lt;/span&gt;&lt;i&gt;α&lt;/i&gt;&lt;span&gt;-subunit of mcr operon to explore the influence of soil climate manipulations on methanogen abundances. Methanogen abundances were greatest in warmed plots, and showed a positive relationship with mean daily CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;fluxes. Our results show that water table manipulations that led to soil inundation (flooding) had a stronger effect on CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;fluxes than water table drawdown. Seasonal CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;fluxes increased by 80–300% under the combined wetter and warmer soil climate treatments. Thus, while warming is expected to increase CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;emissions from Alaskan wetlands, higher water table positions caused by increases in precipitation or disturbances such as permafrost thaw that lead to thermokarst and flooding in wetlands will stimulate CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;emissions beyond the effects of soil warming alone. Consequently, we argue that modeling the effects of climate change on Alaskan wetland CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;emissions needs to consider the interactive effects of soil warming and water table position on CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;production and transport.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1029/2007JG000496</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>American Geophysical Union</dc:publisher>
  <dc:title>Short-term response of methane fluxes and methanogen activity to water table and soil warming manipulations in an Alaskan peatland</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>