Carbon sequestration in forest ecosystems is considered one of the major ways to reduce atmospheric CO2 concentration and mitigate global climate change. Previous efforts on studying the mechanisms for increasing carbon sequestration in ecosystems have been predominantly on biophysical processes such as climate change, land use, and disturbances with little attention to the impacts of social-economic infrastructure. Here we investigate the impact of socioeconomic instruments related to forest resources management (e.g., land rights, tax and financial incentives, and technical assistance programs) on regional forest conditions using observations from 6732 forest inventory plots from two biophysically-similar regions in China (Hunan Province) and the United States (the State of Alabama).
Results/Conclusions
Results show that socioeconomic factors have resulted in drastic regional differences in the age and composition of forests, and the size, height, stocking rate, and carbon storage of trees across these two regions. The forests in Hunan are more heavily tilted towards short-term suboptimal exploitative timber production with a much younger age structure than those in Alabama. On average, the size (i.e., height and diameter at breast height) of trees in Hunan was only half the size in Alabama; the stocking rate of trees (i.e., number of trees per unit area) in Hunan was 69% of that in Alabama. The carbon storage in tree biomass in Hunan was 9.2 Mg C/ha, only 18% of that in Alabama, and the biomass carbon sequestration rate was 0.2 Mg C/ha/yr in Hunan, only about 9% of that in Alabama. These drastic impacts of social-economic forces on forest structure and carbon sequestration services signify the vital role of policy and economic instruments in determining ecosystem carbon storage and sequestration services which has often been ignored previously.