Net ecosystem production (NEP) of boreal bogs in Finland under climate change scenarios - Using tree rings to reconstruct past NEP, C-flux measurements to estimate present NEP and General Circulation Models to project future NEP

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Climate Warming strongly affects boral peatlands and these ecosystems feed-back to climate. Important feedbacks are: 1) Carbon is stored under present conditions in boreal peatlands, reducing atmospheric CO2 concentrations (carbon sink) 2) Boreal peatlands release methane (CH4 source). Warmer and drier conditions might switch boreal peatlands from carbon sink to carbon source, because higher decoposition rates will likely increase CO2 efflux (Feedback 1). However, CH4 efflux (Feedback 2) will likely decrease. Te relative importance of both fluxes is unclear today and a comprehensive assessment of northern European peatlands under warming scenarios is missing. Here, I propose to study fluxes of CO2, CH4 and Dissolved Organic Carbon at boreal bogs in Finnland. Cooperating with Finish partners, I will combine five methods to 1) identify carbon fluxes at plot level, 2) investigate the spatial variability of these fluxes, 3) use tree rings to reconstruct recent change in net ecosystem production and water level (which controls CH4/CO2 efflux) 4) scale results up using IKONOS imagery and 5) ultimately project carbon fluxes for the 21st century using output from General Circulation Models. This unique and powerful approach promises spatially explicit results of the complete carbon balance of boreal bogs in northern Europe and their present and future carbon fluxes under climate warming.