A significant carbon sink in temperate forests in Beijing: based on   20-year field measurements in three stands.
Numerous efforts have been made to characterize forest carbon (C) cycles and stocks in various ecosystems. However, long-term observation on each component of the forest C cycle is still lacking. We measured C stocks and fluxes in three permanent temperate forest plots (birch, oak and pine forest) during 2011–2014, and calculated the changes of the components of the C cycle related to the measurements during 1992–1994 at Mt. Dongling, Beijing, China. Forest net primary production in birch, oak, and pine plots was 5.32, 4.53, and 6.73 Mg C ha-1 a-1, respectively. Corresponding net ecosystem production was 0.12, 0.43, and 3.53 Mg C ha-1 a-1. The C stocks and fluxes in 2011–2014 were significantly larger than those in 1992–1994 in which the biomass C densities in birch, oak, and pine plots increased from 50.0, 37.7, and 54.0 Mg C ha-1 in 1994 to 101.5, 77.3, and 110.9 Mg C ha-1 in 2014; soil organic C densities increased from 207.0, 239.1, and 231.7 Mg C ha-1 to 214.8, 241.7, and 238.4 Mg C ha-1; and soil heterotrophic respiration increased from 2.78, 3.49, and 1.81 Mg C ha-1 a-1 to 5.20, 4.10, and 3.20 Mg C ha-1 a-1. These results suggest that the mountainous temperate forest ecosystems in Beijing have served as a carbon sink in the last two decades. These observations of C stocks and fluxes provided field-based data for a long-term study of C cycling in temperate forest ecosystems.
JianXiao
J
Zhu
XueYang
X
Hu
Hui
H
Yao
GuoHua
G
Liu
ChenJun
C
Ji
JingYun
J
Fang
D000068476:Beijing; D002244:Carbon / Q000378:metabolism; D057486:Carbon Cycle; D057965:Carbon Sequestration; D002681:China; D003247:Conservation of Natural Resources / Q000379:methods; D065928:Forests; D005843:Geography; D018517:Plant Roots / Q000378:metabolism; D012987:Soil; D013997:Time Factors; D014197:Trees / Q000378:metabolism*
D012987:Soil; D002244:Carbon