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。考虑到它们的地理位置，未来几十年它们可能会经历重大的气候和/或土地利用变化。为了预测北方泥炭地的命运，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。我的研究计划以三个总体问题为指导：寒带和北极地区泥炭地生态系统形成和发展的物理、化学和生态控制是什么？北方泥炭地在气候-碳耦合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？我的发现研究的目标是：1)检查泥炭地微观和中观地形、水文（地下水位）、植被和碳（泥炭）积累之间的反馈；2)研究泥炭地模式的形成和维持方式，重点研究控制生物地球化学转化热力学极限的因素；3)确定泥炭地结构和水文随永久冻土融化的变化。将泥炭地视为复杂适应系统（CAS）表明泥炭地形态的产生和维持是水文、植物生产、分解和生物地球化学等多种负反馈作用的结果。在CASs的背景下，我假设地形的规模和变化是生态系统复杂性的一个函数，变化越有规律，泥炭地对外部强迫变量变化的控制范围就越大——也就是说，稳定性越高。我认为泥炭地地形变化的结构是一种自我调节的涌现特性。我将尝试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储量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.