Uncertainty in countrywide forest biomass estimates.

Abstract

Country-wide estimates of forest biomass are the major driver for estimating and understanding carbon pools and flux, a critical component of global change research. Important determinants in making these estimates include the areal extent of forested lands and their associated biomass. Estimates for these parameters may be derived from surface-based data, photo interpretation or satellite remote sensing, with varying degrees of uncertainty. Ground data are typically aggregated by forest type, stand age, productivity level, and ownership. Survey priority is usually given to regions and forest types with timber of commercial value, such that information on understory biomass and forested lands of low commercial value is either absent or of limited reliability. Furthermore, information on below ground biomass, which is costly and time-consuming to collect, is not generally available. Typically, uncertainty in survey statistics increases as the level of post-stratification increases because of reduced sample size. Likewise, literature-based expansion factors also add to the uncertainty of a final estimate because of the often unknown spatial inference for those factors. Estimates based on modeled processes may provide relatively limited information on uncertainty. The discussions in this paper are based on research funded by the U.S. Environmental Protection Agency, and data provided by the U.S. Forest Service.

Citation

Peterson, C.E.; Turner, D. 1994. Uncertainty in countrywide forest biomass estimates. In: Markku Kanninen, ed. Proceedings of the International Panel for Climate Change AFOS workshop; Joensuu, Finland, May 11-15, 1992. Painatuskeskus Oy, Helsinki: Carbon balance of world''s forested ecosystems: towards a global assessment: 98-104.