A Hydrogeophysical Study of Northern Raised Bogs: Implications for Generic Models of Peatland Formation, Vegetation Patterning, Pool Formation and Biogenic Gas Generation

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The processes of peatland development, peatland hydrology and carbon gas cycling within peat bogs need to be better understood in order to improve peatland management and predict the response of these unique ecosystems to climate change. In this research we will implement a geophysics-based approach to investigate three incompletely resolved, current issues in peatlands science: [1] the causes of the unique vegetation structure and patterning observed at the peatland surface [2] controls on the formation of pools encountered in many northern bogs; [3] the basin-scale volume and distribution of free-phase biogenic gasses in peatlands. Our hypothesis is that conceptual models we previously proposed to explain data obtained from Caribou Bog, a multi-unit raised bog in central Maine, pertain to the formation, vegetation patterning and carbon cycling of other ombotrophic raised bogs of Maine that display a surface vegetation and surface hydrology strikingly similar to Caribou Bog. As a first step in testing this hypothesis we plan to collect geophysical data in 1-2 (depending on field conditions encountered) previously unexplored bog of Maine. Our analysis will focus on whether these new datasets are consistent with our conceptual models based on Caribou Bog. The peatlands we have chosen exhibit strikingly similar surface hydrological and ecological characteristics. Our geophysical research using ground penetrating radar (GPR) and electrical imaging will determine whether the subsurface characteristics of these peatlands are correspondingly similar and support the existence of generic models linking subsurface characteristics of peatlands to surface vegetation, surface hydrology and land-atmosphere carbon exchange.A significant educational initiative of our project is a workshop on -Geophysics for Peatlands Scientists- that we will run in the summer of 2007. The fundamental objective of this workshop is to enhance utilization of geophysical methods by peatland scientists across the globe. Geophysical methods are currently underutilized by peatlands scientists and we believe that this is detrimental to the advancement of our understanding of peatland functions. Participants should gain sufficient knowledge to independently apply surface-based ground penetrating radar and electrical imaging methods to their own field-based research. We will train participants in the application of geophysical technologies in peatlands and in the unique interpretation of datasets produced. We expect to reap synergistic benefits as a result of bringing a group of peatland scientists to Maine to debate our hypotheses and the conceptual models we have so far presented in the literature. Our work has global implications as peatlands currently emit significant amounts of carbon gases (25-30% global total of methane), and the response of these large carbon reservoirs to climatic change is highly uncertain. Our work also has regional implications as peatlands are an important ecosystem in Maine, covering about 5% of the landscape. These systems likely play an important role in the hydrology and water quality of the state and correspondingly enhance the state biodiversity.