Factors affecting the distribution of the rate of carbon uptake by forests in South Korea.

The biomass of forests in South Korea has significantly increased during the last 30 years because of a national reforestation project and forest management. Despite the high potential of this biomass for sequestering atmospheric carbon dioxide, little effort has been devoted to identifying the factors affecting the rate of carbon uptake by forests in Korea. Recently, we reported that Korean forests have a higher carbon uptake rate (1.5 Mg C ha(-1) year(-1)) than those of North America, Europe, and China. In this study, as a follow-up to that work, we examine the distributions of total forest carbon, carbon density, and carbon uptake rate at the province and subprovince levels in Korea and elucidate the relationships between forest and climatic variables within these distributions. The provinces can be classified into three distinct groups according to their carbon uptake rate and forest age class: group A (Gyeonggi, Chungbuk, Chungnam), group B (Gyeongbuk, Gyeongnam, Jeonbuk, Jeonnam), and group C (Gangwon, Jeju). When all forest and climatic variables are considered, the provinces Gangwon and Jeju in group C are found to belong to distinct groups. The rate of carbon uptake in each province is not significantly correlated to most forest and climatic variables but is highly correlated to forest age class. A multivariate statistical analysis also supports our conclusion that forest age class is the major factor affecting the current distribution of the rate of carbon uptake in Korea. We conclude that for several decades Korean forests will have a high capacity for sequestering carbon dioxide.