title: Environmental and vegetation controls on the spatial variability of CH4emission from wet-sedge and tussock tundra ecosystems in the Arctic.
abstract: OBJECTIVE
  Despite multiple studies investigating the environmental controls on CH4fluxes from arctic tundra ecosystems, the high spatial variability of CH4emissions is not fully understood. This makes the upscaling of CH4fluxes from plot to regional scale, particularly challenging. The goal of this study is to refine our knowledge of the spatial variability and controls on CH4emission from tundra ecosystems.
  
  
  METHODS
  CH4fluxes were measured in four sites across a variety of wet-sedge and tussock tundra ecosystems in Alaska using chambers and a Los Gatos CO2and CH4gas analyser.
  
  
  RESULTS
  All sites were found to be sources of CH4, with northern sites (in Barrow) showing similar CH4emission rates to the southernmost site (ca. 300 km south, Ivotuk). Gross primary productivity (GPP), water level and soil temperature were the most important environmental controls on CH4emission. Greater vascular plant cover was linked with higher CH4emission, but this increased emission with increased vascular plant cover was much higher (86 %) in the drier sites, than the wettest sites (30 %), suggesting that transport and/or substrate availability were crucial limiting factors for CH4emission in these tundra ecosystems.
  
  
  CONCLUSIONS
  Overall, this study provides an increased understanding of the fine scale spatial controls on CH4flux, in particular the key role that plant cover and GPP play in enhancing CH4emissions from tundra soils.
authors.affiliation: Department of Animal and Plant Science, University of Sheffield, Western Bank, Sheffield S10 2TN UK.
authors.forename: Katherine Rose
authors.initials: KR
authors.lastname: McEwing
authors.affiliation: Department of Animal and Plant Science, University of Sheffield, Western Bank, Sheffield S10 2TN UK.
authors.forename: James Paul
authors.initials: JP
authors.lastname: Fisher
authors.affiliation: Department of Animal and Plant Science, University of Sheffield, Western Bank, Sheffield S10 2TN UK ; Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 USA.
authors.forename: Donatella
authors.initials: D
authors.lastname: Zona
keywords: Arctic; Climate change; Greenhouse gas emission; Permafrost; Vegetation control
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