Stable Carbon composition of Methane in Eurasian Peatlands: CH4 production, transport and oxidation

欧亚泥炭地是大气中温室气体CH 4的重要来源。然而，目前尚不清楚是否在北方泥炭地的甲烷通量的强度会改变在气候变化。在这里，我们建议缩小这一知识差距，调查机制的CH 4平衡生产泥炭剖面和消费泥炭氧化带以及CH 4运输机制。调查将沿沿着从芬兰到俄罗斯西北部最大泥炭地之一的海洋-大陆样带进行。在每个站点，我们将测量（一）孔隙水CH 4浓度和排放CH 4流出，（二）浓度的乙酸作为底物产甲烷;（三）稳定的C同位素组成的孔隙水-和排放CH 4，以评估来源的产甲烷，CH 4-氧化潜力和可能的机制CH 4运输从泥炭深度到大气。所获得的数据将提高对空间（从微观尺度-泥炭地的微观形态：丘、草坪、洼地-到宏观尺度沿着海洋-大陆样带）和时间（春夏季节）尺度上CH 4周转机制的认识。知识的具体机制内的CH 4周转北方泥炭地将有助于在新的发展和调整现有的全球和区域模型的C平衡。

Eurasian peatlands are important sources of the greenhouse gas CH4 to the atmosphere. However, it is not clear whether the intensity of CH4 flux within boreal peatlands would alter in a changing climate. Here, we propose to narrow this knowledge gap by investigating mechanisms of the CH4 balance between production within peat profile and consumption in peat oxidative zones as well as CH4 transport mechanisms. The investigation will be conducted along a maritimecontinental transect spanning from Finland to one of largest peatlands areas in North-Western Russia. At each site, we will measure (i) porewater CH4 concentrations and emitted CH4 efflux, (ii) concentrations of acetates as substrates for methanogenesis; (iii) stable C isotopic composition of porewater- and emitted CH4 to assess the sources of methanogenesis, CH4-oxidative potential and possible mechanisms of CH4 transport from peat depth to the atmosphere. Obtained data will improve the knowledge about mechanisms of the CH4 turnover on both spatial (from micro-scale - peatland’s microforms: hummocks, lawns, hollows - to macro-scale along a maritime-continental transect) and temporal (over spring-summer seasons) dimensions. Knowledge of the specific mechanisms of CH4 turnover within boreal peatlands will help in the development of the new- and adjustment of the existing global- and regional models of C balance.