HR: 17:45h
AN: B44B-08    [Abstracts]
TI: Bias and Variability in Biometric Estimates of Forest Woody Carbon Gain at Landscape Scales: An Empirical Test in North Central Wisconsin.
AU: * Bolstad, P V
EM: pbolstad@umn.edu
AF: University of Minnesota, Department of Forest Resources, 1530 Cleveland Ave. N., St Paul, MN 55108 United States
AU: Desai, A
EM: adesai@psu.edu
AF: Pennsylvania State University, Department of Meteorology and Atmospheric Sciences, 512 Walker Bldg, University Park, PA 16802 United States
AU: Cook, B
EM: bcook@umn.edu
AF: University of Minnesota, Department of Forest Resources, 1530 Cleveland Ave. N., St Paul, MN 55108 United States
AU: Davis, K J
EM: davis@essc.psu.edu
AF: Pennsylvania State University, Department of Meteorology and Atmospheric Sciences, 512 Walker Bldg, University Park, PA 16802 United States
AB: A central hypothesis in the North American Carbon Plan is that ecosystem-atmosphere carbon exchange can be quantified and uncertainties reduced by implementing a hierarchy of measurements, from high-intensity 'Tier 4' sites through successively less intensive but more extensive sampling of three more 'Tiers'. We report on Tier 2 measurements, biometric sampling to estimate structure, growth, and mortality, and changes in carbon pools over a mixed forest-wetland landscape in northern Wisconsin. We oversampled forest structure and woody growth rates, and combined these with existing large-area Forest Inventory and Analysis measurements. Coefficients of variation in estimates of above ground storage declined exponentially with sample size, but were still larger than mean values at sampling densities approaching one sample per 100 hectares. Landscape estimates of aboveground C pools and C growth were positively biased under most sampling intensities and regimes because of wetland undersampling. Pools and growth rates varied most strongly in response to stocking, were not strongly related to simple satellite-based indices of leaf area, and were moderately related to species groups. Improving the accuracy of landscape stocking measurements will complement existing satellite-based measurements of species groups and substantially improve estimates of forest carbon pools and fluxes.
DE: 0428 Carbon cycling (4806)
DE: 0476 Plant ecology (1851)
DE: 0497 Wetlands (1890)
SC: Biogeosciences [B]
MN: Fall Meeting 2005