The ecohydrology and biogeochemistry of northern peatland ecosystems

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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.