The ecohydrology and biogeochemistry of northern peatland ecosystems

泥炭地生态系统含有世界上约25%的陆地活性碳，是大气甲烷的重要来源。鉴于它们的地理位置，它们很可能在未来几十年经历显着的气候和/或土地利用变化。要预测北部泥炭地的命运，我们需要了解气候、水文和生态过程如何决定泥炭地的结构和功能。我的研究计划是围绕三个主要问题展开的：北部和北极地区泥炭地生态系统的形成和发展的物理、化学和生态控制是什么？北部泥炭地在气候-碳系统中的作用是什么？环境变化将如何改变泥炭地的结构和功能？我的探索研究的目标是：1)研究泥炭地微地形和中地形、水文学(地下水位)、植被和碳(泥炭)积累之间的反馈；2)调查泥炭地格局是如何形成和维持的，重点是控制生物地球化学转化的热力学极限的因素；3)确定泥炭地结构和水文如何随着永久冻土的融化而变化。将泥炭地视为复杂适应系统(CAS)表明，泥炭地的产生和维持是水文、植物生产、分解和生物地球化学之间的几个负反馈的结果。在CASS I的背景下，假设地形的规模和变化是生态系统复杂性的函数，变化越规则，泥炭地对外部强迫变量变化的控制范围就越大--即更大的稳定性。我认为，泥炭地地形变化的结构是一种自我调节的紧急性质。我将试图通过理论和实证研究来证伪这些假设。这项研究的结果将有助于确定泥炭地碳库在未来环境变化中的命运。

Peatland ecosystems contain about 25% of the world's active terrestrial carbon and are significant sources of atmospheric methane. Given their geographic location they will likely experience significant climate and/or land-use change over the next decades. To project the fate of northern peatlands we need to understand how climate, hydrology, and ecological processes determine peatland structure and function. My research program is guided for three overarching questions: What are the physical, chemical and ecological controls of the formation and development of peatland ecosystems in the boreal and arctic regions?; What is the role of northern peatlands in the couple climate-carbon system?; and How will environmental change alter the structure and function of peatlands? The objectives of my Discovery research are to: 1) examine the feedbacks among peatland micro- and mesotopography, hydrology (water table), vegetation, and carbon (peat) accumulation; 2) investigate how patterns form and are maintained on peatlands, focussing on factors that control the thermodynamic limits of biogeochemical transformations; and 3) determine how peatland structure and hydrology change with the thawing of permafrost. Treating peatlands as complex adaptive systems (CAS) shows the production and maintenance of peatland form results from several negative feedbacks among hydrology, plant production, decomposition, and biogeochemistry. Within the context of CASs I hypothesize that scale and variance of topography is a function of the ecosystem's complexity and the more regular the variance the greater the range of control a peatland has to changes in external forcing variables - i.e. greater stability. I propose that the structure of the variance in a peatland's topography is an emergent property of self-regulation. I will attempt to falsify these hypotheses through both theoretical and empirical studies. The results of this research will help determine the fate of the peatland carbon store in future environmental change.