NSF BIOCOMPLEXITY MODELLING GRANT
Project Summary:
Scott Bridgham, Department of
Biological Sciences, University of Notre Dame
John Pastor, Natural Resources Research Institute, University of Minnesota, Duluth
Nigel Roulet, Department of Geography, McGill University, Montreal, Quebec
Steve Frolking, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham
Jiquan Chen, School of Forestry and Wood Products, Michigan Technological University, Houghton
Jake Weltzin, Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville.
Northern peatlands are an important component of the global carbon cycle, but existing models of carbon accumulation fail to include potential complex behaviors. At least two feedbacks that are unique to these ecosystems will likely cause complex behaviors both spatially and temporally: (1) organic matter accumulation is controlled by hydrology, but as thick organic deposits accumulate, they in turn control the hydrology and resulting biogeochemical environments. (2)Sphagnum mosses are a dominant component of productivity in many peatlands, but they influence nutrient and carbon fluxes unlike any other vegetation type. First, mosses acquire all of their nutrient inputs from the atmosphere or the first several cm of surface peat, resulting in soil nutrient uptake that is vertically segregated from vascular plants. Secondly, mosses decay at extremely slow rates and have very low nutrient concentrations. Thus, mosses act as a strong filter for nutrient fluxes to other plant life forms, and thereby introduce a delay in the flux of nutrients through peatlands.
The objective of this incubation proposal is to bring together two research groups that have developed separate models of peatlands which display complex behaviors. Roulet and Frolking have developed models of feedbacks between carbon accumulation and hydrology, whereas Bridgham, Pastor, Chen and Weltzin have developed a model of feedbacks between plant communities and nutrient availability. We will achieve our objective by hiring a postdoctoral associate and holding two group meetings to (1) integrate these two modeling approaches, (2) explore the complex dynamics of the models, and (3) develop a framework for a more comprehensive simulation model that can both (i) simulate the initiation and development of peatlands over thousands of years and the resulting pattern of different peatland ecosystems that form on the landscape, and (ii) explore their shorter term response to climate change. We will use the results of these incubation efforts to submit a full proposal to the Biocomplexity Special Competition in two years to finalize the development of, experimentally parameterize, and test this ecosystem model. This model will provide great insight into the complex behaviors of these unique ecosystems and will be invaluable in predicting the effects and potential feedbacks of climate change on peatlands. Furthermore, the construction and analysis of this model will provide the focus for building collaborations among our groups.
FUNDED 2000, BY NSF
Below is the proposal as pdf files.