Surface radiative forcing of forest disturbances over northeastern China

Abstract

Forests provide important climate forcing through biogeochemical and biogeophysical processes. In this study, we investigated the climatic effects of forest disturbances due to changes in forest biomass and surface albedo in terms of radiative forcing over northeastern China. Four types of forest disturbances were considered: fires, insect damage, logging, and afforestation and reforestation. The mechanisms of the influence of forest disturbances on climate were different. ‘Instantaneous’ net radiative forcings caused by fires, insect damage, logging, and afforestation and reforestation were estimated at 0.53 ± 0.08 W m−2, 1.09 ± 0.14 W m−2, 2.23 ± 0.27 W m−2, and 0.14 ± 0.04 W m−2, respectively. Trajectories of CO2-driven radiative forcing, albedo-driven radiative forcing, and net forcing were different with time for each type of disturbance. Over a decade, the estimated net forcings were 2.24 ± 0.11 W m−2, 0.20 ± 0.31 W m−2, 1.06 ± 0.41 W m−2, and −0.47 ± 0.07 W m−2, respectively. These estimated radiative forcings from satellite observations provided evidence for the mechanisms of the influences of forest disturbances on climate.