Lability of organic carbon stored in permafrost peatlands

全球三分之一的土壤碳储存在北方泥炭地。如今，储存在永久冻土区泥炭地中的有机碳正受到气候变暖的威胁。如果土壤有机碳的分解率增加，以应对温度升高和水文变化（由于永久冻土融化），可能会有大量的二氧化碳进入大气。为了了解北方泥炭地对气候系统的潜在反馈，必须了解控制土壤有机碳分解速率的机制。目前，土壤有机碳化学及其与高纬度生态系统潜在碳损失的关系的信息不足，限制了我们了解这一全球重要碳库命运的能力。这项研究将结合联合收割机在亚北极泥炭地，实验室实验，并通过固态13 C核磁共振碳化学的复杂分析二氧化碳的现场测量。这种方法将揭示土壤碳化学对永久冻土泥炭地二氧化碳排放的作用。这项工作将是第一步，预测碳损失的永久冻土泥炭地的土壤有机碳的分解能力的机械理解的基础上。

One third of the global soil carbon is stored in northern peatlands. Today, the organic carbon stored in peatlands in permafrost regions, is under threat from climate warming. If the decomposition rates of the soil organic carbon increases, in response to increased temperature and altered hydrology (due to melting permafrost), potentially large quantities of carbon dioxide could enter the atmosphere. In order to understand the potential feed backs from northern peatlands to the climate system it is essential to understand the mechanisms that control soil organic carbon decomposition rates. Currently, poor information of soil organic carbon chemistry and how it is related to potential carbon loss from high latitude ecosystems limits our ability to understand the fate of this globally important carbon pool. This study will combine field measurement of carbon dioxide in subarctic peatlands, laboratory experiments, and sophisticated analysis of the carbon chemistry by solid state 13C NMR. This approach will unravel the role of soil carbon chemistry for carbon dioxide emissions from permafrost peatlands. This work would be a first step towards predicting carbon losses from permafrost peatlands based on mechanistic understanding of the decomposability of the soil organic carbon.