CARBON-BIOSPHERE-CLIMATE INTERACTIONS IN THE LAST GLACIAL MAXIMUM CLIMATE

The total carbon inventory in the terrestrial biosphere in the last gl acial maximum (LGM), 18 kyr ago, is analyzed in a series of experiment s that examine the sensitivity of the inventory to vegetation distribu tion and carbon dynamics. The results show that for most forest vegeta tion types, carbon densities for the LGM are within 10% of their prese nt-day values. Discrepancies between vegetation distributions simulate d by two bioclimatic schemes are attributable to the assignation of ve getation types to climates with rare or no present-day analog. The mod el experiments, combined with palynogical data for regions with no pre sent-day analog climate, yield to a decrease of 612 +/- 105 Gt C compa red to present day.