title: Stability of peatland carbon to rising temperatures.
abstract: Peatlands contain one-third of soil carbon (C), mostly buried in deep, saturated anoxic zones (catotelm). The response of catotelm C to climate forcing is uncertain, because prior experiments have focused on surface warming. We show that deep peat heating of a 2 m-thick peat column results in an exponential increase in CH4emissions. However, this response is due solely to surface processes and not degradation of catotelm peat. Incubations show that only the top 20-30 cm of peat from experimental plots have higher CH4production rates at elevated temperatures. Radiocarbon analyses demonstrate that CH4and CO2are produced primarily from decomposition of surface-derived modern photosynthate, not catotelm C. There are no differences in microbial abundances, dissolved organic matter concentrations or degradative enzyme activities among treatments. These results suggest that although surface peat will respond to increasing temperature, the large reservoir of catotelm C is stable under current anoxic conditions.
authors.affiliation: Earth, Ocean and Atmospheric Sciences, Florida State University, 117 N Woodward Avenue, Tallahassee, Florida 32306, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Wilson
authors.affiliation: Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon 97403, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Hopple
authors.affiliation: Environmental Molecular Sciences Laboratory-Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Tfaily
authors.affiliation: USDA Forest Service Northern Research Station, Grand Rapids, Minnesota 55744, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Sebestyen
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: C W
authors.initials: CW
authors.lastname: Schadt
authors.affiliation: Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon 97403, USA.
authors.forename: L
authors.initials: L
authors.lastname: Pfeifer-Meister
authors.affiliation: Schmid College of Science and Technology, Chapman University, Orange, California 92866, USA.
authors.forename: C
authors.initials: C
authors.lastname: Medvedeff
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: K J
authors.initials: KJ
authors.lastname: McFarlane
authors.affiliation: School of Biological Sciences and School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Kostka
authors.affiliation: School of Biological Sciences and School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kolton
authors.affiliation: USDA Forest Service Northern Research Station, Grand Rapids, Minnesota 55744, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Kolka
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Kluber
authors.affiliation: Schmid College of Science and Technology, Chapman University, Orange, California 92866, USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Keller
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: T P
authors.initials: TP
authors.lastname: Guilderson
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: N A
authors.initials: NA
authors.lastname: Griffiths
authors.affiliation: Earth, Ocean and Atmospheric Sciences, Florida State University, 117 N Woodward Avenue, Tallahassee, Florida 32306, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Chanton
authors.affiliation: Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon 97403, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Bridgham
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Hanson