title: Reconstruction of the carbon balance for microsites in a boreal oligotrophic pine fen, Finland.
abstract: Carbon dioxide (CO2) exchange was studied at flark (minerotrophic hollow), lawn and hummock microsites in an oligotrophic boreal pine fen. Statistical response functions were constructed for the microsites in order to reconstruct the annual CO2exchange balance from climate data. Carbon accumulation was estimated from the annual net CO2exchange, methane (CH4) emissions and leaching of carbon. Due to high water tables in the year 1993, the average carbon accumulation at the flark, Eriophorum lawn, Carex lawn and hummock microsites was high, 2.91, 6.08, 2.83 and 2.66 mol C m-2, respectively, and for the whole peatland it was 5.66 mol m-2year-1. During the maximum primary production period in midsummer, hummocks with low water tables emitted less methane than predicted from the average net ecosystem exchange (NEE), while the Carex lawns emitted slightly more. CH4release during that period corresponded to 16% of the contemporary NEE. Annual C accumulation rate did not correlate with annual CH4release in the microsites studied, but the total community CO2release seemed to be related to CH4emissions in the wet microsites, again excluding the hummocks. The dependence of CO2exchange dynamics on weather events suggests that daily balances in C accumulation are labile and can change from net carbon uptake to net release, primarily in high hummocks on fens under warmer, drier climatic conditions.
authors.affiliation: Department of Biology, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland, , , , , , FI.
authors.forename: J
authors.initials: J
authors.lastname: Alm
authors.affiliation: Institute of Biology, Karelian Research Centre of Russian Academy of Sciences, Puskinskaja St. 11, SU-185610 Petrozavodsk, Russia, , , , , , RU.
authors.forename: Alexander
authors.initials: A
authors.lastname: Talanov
authors.affiliation: Department of Biology, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland, , , , , , FI.
authors.forename: Sanna
authors.initials: S
authors.lastname: Saarnio
authors.affiliation: Department of Biology, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland, , , , , , FI.
authors.forename: Jouko
authors.initials: J
authors.lastname: Silvola
authors.affiliation: Institute of Biology, Karelian Research Centre of Russian Academy of Sciences, Puskinskaja St. 11, SU-185610 Petrozavodsk, Russia, , , , , , RU.
authors.forename: Elena
authors.initials: E
authors.lastname: Ikkonen
authors.affiliation: Department of Biology, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland, , , , , , FI.
authors.forename: Heikki
authors.initials: H
authors.lastname: Aaltonen
authors.affiliation: Laboratory of Environmental Microbiology, National Public Health Institute, P.O. Box 95, FIN-70701 Kuopio, Finland, , , , , , FI.
authors.forename: Hannu
authors.initials: H
authors.lastname: Nykänen
authors.affiliation: Laboratory of Environmental Microbiology, National Public Health Institute, P.O. Box 95, FIN-70701 Kuopio, Finland, , , , , , FI.
authors.forename: Pertti J
authors.initials: PJ
authors.lastname: Martikainen
keywords: CH4; Carbon accumulation; Climate; Key words Peatland ecosystem; Microsite