title: Carbon exchange fluxes over peatlands in Western Siberia: Possible feedback between land-use change and climate change.
abstract: The growing demand for agricultural products has been leading to an expansion and intensification of agriculture around the world. More and more unused land is currently reclaimed in the regions of the former Soviet Union. Driven by climate change, the Western Siberian grain belt might, in a long-term, even expand into the drained peatland areas to the North. It is crucial to study the consequences of this land-use change with respect to the carbon cycling as this is still a major knowledge gap. We present for the first time data on the atmosphere-ecosystem exchange of carbon dioxide and methane of an arable field and a neighboring unused grassland on peat soil in Western Siberia. Eddy covariance measurements were performed over one vegetation period. No directed methane fluxes were found due to an effective drainage of the study sites. The carbon dioxide fluxes appeared to be of high relevance for the global carbon and greenhouse gas cycles. They showed very site-specific patterns resulting from the development of vegetation: the persistent plants of the grassland were able to start photosynthesizing soon after snow melt, while the absence of vegetation on the managed field lead to a phase of emissions until the oat plants started to grow in June. The uptake peak of the oat field is much later than that of the grassland, but larger due to a rapid plant growth. Budgeting the whole measurement period, the grassland served as a carbon sink, whereas the oat field was identified to be a carbon source. The conversion from non-used grasslands on peat soil to cultivated fields in Western Siberia is therefore considered to have a positive feedback on climate change.
authors.affiliation: Institute of Landscape Ecology, Climatology Research Group, University of Münster, Münster, Germany. Electronic address: elisa.fleischer@uni-muenster.de.
authors.forename: Elisa
authors.initials: E
authors.lastname: Fleischer
authors.affiliation: Institute of Earth Science, Physical Geography and Geoecology Department, Tyumen State University, Tyumen, Russia. Electronic address: nixonlp@mail.ru.
authors.forename: Ilhom
authors.initials: I
authors.lastname: Khashimov
authors.affiliation: Institute of Landscape Ecology, Biodiversity and Ecosystem Research Group, University of Münster, Münster, Germany. Electronic address: nhoelzel@uni-muenster.de.
authors.forename: Norbert
authors.initials: N
authors.lastname: Hölzel
authors.affiliation: Institute of Landscape Ecology, Climatology Research Group, University of Münster, Münster, Germany. Electronic address: otto.klemm@uni-muenster.de.
authors.forename: Otto
authors.initials: O
authors.lastname: Klemm
keywords: Agricultural sustainable intensification; Carbon balance; Eddy covariance; Former Soviet Union; Greenhouse gas fluxes; Land conversion