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

气候变暖强烈地影响着硼泥炭地，这些生态系统反馈到气候。重要的反馈包括：1）碳在目前条件下储存在北方泥炭地，降低大气CO2浓度（碳汇）2）北方泥炭地释放甲烷（CH 4源）。更温暖和更干燥的条件可能会将北方泥炭地从碳汇转变为碳源，因为更高的分解率可能会增加CO2的排放（反馈1）。然而，CH 4流出（反馈2）可能会减少。这两种通量的相对重要性目前尚不清楚，在变暖情景下对北方欧洲泥炭地的全面评估也缺失。在这里，我建议研究芬兰北部沼泽的CO2，CH 4和溶解有机碳通量。与芬兰合作伙伴合作，我将结合联合收割机五种方法1）确定地块水平的碳通量，2）调查这些通量的空间变异性，3）利用树木年轮重建生态系统净生产力和水位的近期变化（控制CH 4/CO2排放）4）使用IKONOS图像放大结果，5）利用大气环流模式的输出结果，最终预测21世纪的碳通量。这种独特的和强大的方法承诺空间明确的结果，在北方欧洲北部的沼泽和他们现在和未来的碳通量下的气候变暖的完整的碳平衡。

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.