PROCEEDINGS: Index of Abstracts

SPATIAL PATTERNS IN CARBON STORAGE IN A LAKE STATES' LANDSCAPE

J. C. Bell-1, D. F. Grigal-1, P. C. Bates-1, and C. A. Butler-2

1-Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN 55108. 2-Natural Resources Management Program, Western Carolina University, Cullowhee, NC 28723.

We estimated total organic carbon storage (C -- kg m^-2) in biomass, forest floor, and soil for a gently undulating glacial outwash landscape in east-central Minnesota (45° 25'N, 93° 10'W). Abandoned agricultural tracts are common, and nearly 40 percent of the area is wet mineral or organic soil. Quantitative models based on 745 point-observations were used to define empirical relationships between C storage and landscape variables describing forest cover type and terrain characteristics. Exponential regressions for individual cover types explained from 31 to 70 percent (p<0.05) of the variation in soil C and 39 percent (p<0.05) of the variation in peatland depth. Spatial patterns and quantities of C storage were estimated by applying these functions to a digital geographic database of cover type and terrain attributes. Landscape scale (~1:20,000) estimates of soil C followed a bimodal distribution with means at 4 kg m^-2 (mineral soils) and 130 kg m^-2 (peatlands). Biomass carbon for individual cover types ranged from 1 to 13 kg m^-2. Total C storage in all components, based on a 1m soil depth, was 32 kg m^-2, with over 90 percent stored in peatlands.