Abstract: Forest is the largest carbon (C) pool in terrestrial ecosystem. Under the background of global warming, the influence of forest management on the C pool is increasingly drawing the attention of scientists all over the world. Most of the literatures in China consider that the harvested wood products (HWP) discharge C at current year, but actually, the C in HWP can be deposited for a long time. According to the usage and harvesting practices of HWP, the HWP were divided as 1) harvested residues (DBH ≤6 cm), and 2) solid wood products and paper products (DBH >6 cm). This paper investigated the DBH and tree species composition before and after harvesting in the broadleaved-Korean pine mixed forests in Changbai Mountain, and studied the dynamic changes of the forest C storage, based on the actual emission of C from HWP. The results showed that the C storage of harvested residues was 1.1 t C, and the C emission speed changed from fast to slow. The total C emission would last over 80 years. The C storage of solid wood products was 20.56 t C, and the cumulated C emission in 80 years reached 20.07 t C (97.71%). The C storage of paper products was 3.63 t C, and the cumulated C emission would reach 3.45 t C (95.13%) in the first 7 years. If the C emission from HWP was considered at current year, the forest C pool would take 20 years to reach the level before harvesting; if considering the actual C emission from HWP, the forest C pool would be always larger than the level before harvesting. Therefore, it would be reasonable and meaningful to consider the actual C emission from HWP so as to accurately estimate the forest C storage in China.

Key words: Grey model, Nutrients, Chlorophyll a, Phytoplankton, Red tide, Daya bay