SOIL CARBON-DIOXIDE CHARACTERISTICS UNDER DIFFERENT FOREST TYPES AND AFTER HARVEST

To characterize soil CO, under different forest types and several year s after a clear-cut harvest, soil CO, evolution and soil air CO2 conce ntrations were measured at three sites in Maine: the Howland Integrate d Forest Study (HIFS) site, the Bear Brook Watershed in Maine (BBWM) s ite, and the Letter E township (Letter E) site. Soil CO2 evolution mea ns ranged from 0.19 to 0.32 g m-2 h-1 among sites, whereas soil air CO 2 concentration means ranged from 1023 muL L-1 for the O horizon to 32 % muL L-1 for the C horizon for the 1990 growing season. Soil CO2 evol ution and soil air CO2 concentrations were similar under deciduous and coniferous forests and 4 to 6 yr after harvest. Limited multiple-year data suggest that significant annual variations in temporal patterns of these properties exist as a function of short-term climatic factors . These data suggest that soil CO2 evolution and soil air CO2 concentr ations may be somewhat similar across a diversity of soil types, fores t types, and forest conditions at any point in time for northern New E ngland.