Complete forest carbon cycle and budget in China, 1999–2008

Abstract

Forest carbon cycle consists of biological and industrial cycles, whose carbon budget and carbon stock change should be estimated. The complete forest carbon budget was seldom reported in China, and carbon budget was mainly used to calculate forest biological carbon stock change. Therefore, we analyzed and presented the complete forest carbon cycle by dividing it into three carbon pools: pre-harvest forest, harvested wood product (HWP) manufacturing, and HWP use and disposal. Then, the carbon budget and net carbon flux of each pool during 1999–2008 were calculated using forest inventory data, HWP production and consumption, and economic data. The results showed that about 1334.46 and 1423.84TgC carbon were sequestered from atmosphere in 1999–2003 and 2004–2008, respectively. The two periods had forest ecosystem net carbon flux of 1356.29 and 1442.90TgC, adding up to 2799.19TgC. For the industrial part, 112.14Tg carbon was stored in new HWP, but 40.86Tg more carbon was released from HWP production, use and disposal. We went onto compare the carbon budgets of 1999–2003 and 2004–2008, and found out that net sequestered carbon was 89.38TgC higher in the latter period, 86.61TgC more stored in forest ecosystem and 2.77TgC less released from the industrial carbon cycle. Subsequently, we studied the relationship between carbon emission reduction and forest industrial carbon cycle, and verified that optimizing HWP production process and extending HWP lifespan can effectively reduce carbon emission. At the end, we proposed gaps and future studies.