HR: 0800h
AN: H51H-0865    [Abstracts]
TI: Geophysical Evidence for Abiotic Controls on Peatland Patterning at Multiple Scales
AU: * Nolan, J
EM: jtnolan@pegasus.rutgers.edu
AF: Department of Earth & Environmental Science, Rutgers University, 101 Warren Street, Newark, NJ 07042, United States
AU: Slater, L
EM: lslater@andromeda.rutgers.edu
AF: Department of Earth & Environmental Science, Rutgers University, 101 Warren Street, Newark, NJ 07042, United States
AU: Glaser, P
EM: glese001@umn.edu
AF: Geology and Geophysics, University of Minnesota, Pillsbury Hall, Minneapolis, MN 55455, United States
AU: Comas, X
EM: xcomas@fau.edu
AF: Department of Geosciences, Florida Atlantic University, 777 Glades Road, room 360, Boca Raton, FL 33431, United States
AU: O'Brien, M
AF: Department of Earth & Environmental Science, Rutgers University, 101 Warren Street, Newark, NJ 07042, United States
AB: The autogenic and allogenic controls on the formation of distinctive and dramatic vegetation patterning found in northern peatlands remain unclear. Groundwater model studies and investigations using point measurements lack intensive data over multiple scales, primarily due to the intensive time required and difficult logistics required to work in these remote ecosystems. We provide geophysical evidence that lithological controls on vegetation patterning exist at multiple scales in ombrotrophic peatlands of northern Minnesota and Maine. Surveys using electrical imaging methods (including resistivity, induced polarization, and ground penetrating radar) at sites in the Red Lake Peatland Complex (160 km²), as well as Kanokolus Bog (1.65 km²) and the Caribou Bog Peatland Complex (22 km²) in Maine reveal sharp vegetation gradients coinciding with changes in the mineral soil lithology. In contrast, large-scale, continuous, patterned zones found in the Red lake Complex coincide with strikingly uniform mineral soil lithology as inferred from the geophysical images. Small-scale (0.3 km²) vegetation patterns observed in Caribou Bog also coincide with small scale lithologic changes in both the mineral and organic deposits. These results provide evidence that the subsurface hydrogeologic framework regulates vegetation patterning in peatlands across multiple scales, presumably by regulating (1) the supply of mineral solutes to the surface vegetation water, and (2) water levels within the organic soil.
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1813 Eco-hydrology
DE: 1847 Modeling
DE: 1874 Ungaged basins
DE: 1879 Watershed
SC: Hydrology [H]
MN: 2007 Fall Meeting