Das Projekt "Effects of climate change on plant-microbe interactions for nutrient acquisition in bogs: implications for carbon and nutrient dynamics (CLIMABOG)" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft, Eidgenössisches Institut für Schnee- und Lawinenforschung durchgeführt. The research project CLIMABOG aims at assessing the relationships between plants and microbes for nutrient acquisition in peatlands (bogs) and potential feedbacks on soil biogeochemistry along a gradient of increasing peat soil temperature. Peatlands are important sinks of atmospheric carbon dioxide and although they cover about 3Prozent of world land cover, peatlands store about 30Prozent of world soil organic carbon or 60Prozent of the carbon present in the atmosphere. Bogs are peatlands dominated by Sphagnum mosses, a peculiar type of plants producing a litter extremely refractory to decomposition so that the remnants of Sphagnum plants accumulate as 'peat'. Because Sphagnum productivity is dependent on water surplus, bogs are particularly sensitive to climate change. Some laboratory experiments suggest that increasing peat soil temperature can promote the growth of vascular plants at expense of Sphagnum mosses through an alteration of plant competitive ability for nutrient acquisition with respect to soil microbes. A better understanding of the effects of climate warming on plant-microbe interactions in bogs is then crucial for predicting the potential alteration of peat accumulation rates. In CLIMABOG the increasing peat soil temperature will be obtained by selecting the study bogs along an altitudinal gradient so as to assess the effects of climate warming under conditions of long-term equilibrium between biogeochemistry, vegetation and local climatic conditions. The research project will include both field observations along one entire year (so as to include also the winter season), and a mesocosm experiment where peat monoliths will be transplanted to lower altitude so as to study the biological and physico-chemical reactions of the system to a sudden climate change. By means of information concerning soil enzymatic activity, microbial diversity and abundance, plant biomass and productivity, peat and water chemistry, we want to assess: 1) how microbial biomass nutrients change during the year in relation to vascular plant growth; 2) how soil enzymatic activity changes along the year and along the altitudinal gradient; 3) how standing biomass of vascular plants and Sphagnum growth vary along the altitudinal gradient; 4) if there is any difference in the microbial diversity in relation to increasing peat soil temperature. A better understanding of the aboveground and belowground interactions in peatlands in response to climate change will permit to better forecast the future carbon sinking ability of these ecosystems