Dissertation Research: Controls on Methane Flux from Arctic Tundra

高纬度生态系统是对气候变化加速最敏感的生态系统之一，其中一些生态系统的温度上升速度最快，水文模式也发生了改变。锁定在北方土壤中的丰富碳储量越来越容易以甲烷的形式释放到大气中，甲烷是一种强大的温室气体，随着大气浓度的增加，可能会进一步加快变暖的速度。 影响天然湿地生态系统产生和释放甲烷量的两个主要环境因素是（1）土壤的湿润程度，以及（2）土壤的温暖程度，但人们对这些因素在季节性过渡时期（如晚春，土壤解冻并失去积雪）如何相互作用知之甚少。该项目使用便携式温室气体分析仪测量2013年春季过渡期和夏季生长季节期间北方芬兰沼泽的甲烷气体排放量，使用融雪和土壤操作实验来确定这些变量对甲烷排放率的影响。高纬度系统中的甲烷研究对我们了解未来气候动态至关重要。这项研究不仅将有助于对北方湿地的甲烷循环的科学了解，而且还将有助于改进全球气候模型，为国际气候变化决策提供信息。此外，这项研究认识到，气候变化不仅仅是一个国家的问题，并促进跨国比较与作者？正在进行的阿拉斯加湿地研究。实地工作将包括一名PolarTREC志愿者的参与，一名美国中学科学教师，这将为向美国年轻人宣传这项研究提供多种外展渠道。将在芬兰和美国开展更多的外联和实地教学机会。

High-latitude ecosystems are among the most sensitive to accelerating climate change, with some of the highest rates of temperature increase and altered hydrological patterns. The rich carbon reserves locked in northern soils are increasingly prone to being released into the atmosphere as methane, a powerful greenhouse gas that, as atmospheric concentrations increase, is liable to further increase the speed of warming. The two major environmental factors that affect the amount of methane being made and released from natural wetland ecosystems are (1) how wet the soil is, and (2) how warm the soil is, but little is known about how these factors interact during seasonal transition periods like late spring, when soils thaw and lose snow cover. This project uses a portable greenhouse gas analyzer to measure methane gas emissions from a northern Finnish mire during the 2013 spring transition period and summer growing season, using snow-melting and soil manipulation experiments to determine the influence of these variables on methane emission rates.Precisely because they are experiencing climate changes at faster rates than the rest of the planet, methane studies in high-latitude systems are critical to our understanding of future climate dynamics. This research will contribute not only to scientific knowledge of methane cycling in northern wetlands, but also to improving global climate models that inform international climate change policymaking. Moreover, this research recognizes that climate change is not merely a national issue, and facilitates trans-national comparisons with the authors? ongoing study of Alaskan wetlands. The field work will include the participation of a PolarTREC volunteer, an American middle school science teacher, which will provide multiple outreach avenues for informing young Americans about this research. Additional outreach and field-based teaching opportunities will be conducted, both in Finland and America.