Carbon budgets of three temperate forest ecosystems in Dongling Mt.,Beijing,China  

作　　者：FANG JingYun  LIU GuoHua  ZHU Biao  WANG XiaoKe  LIU ShaoHui 

机构地区：[1]Department of Ecology, College of Environmental Sciences, and Key Laboratoryfor Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China

出　　处：《Science China Earth Sciences》2007年第1期92-101,共10页中国科学（地球科学英文版）

基　　金：Supported by the National Natural Science Foundation of China (Grant No. 40228001, 40021101 and 90211016)

摘　　要：There is a general agreement that forest ecosystems in the NorthernHemisphere function as significant sinks for atmospheric CO_2; however, their magnitude anddistribution remain large uncertainties. In this paper, we report the carbon (C) stock and itschange of vegetation, forest floor detritus, and mineral soil, annual net biomass increment andlitterfall production, and respiration of vegetation and soils between 1992 to 1994, for threetemperate forest ecosystems, birch (Betula platyphylla) forest, oak (Ouercus liaotungensis) forestand pine (Pinus tabulaeformis) plantation in Mt. Dongling, Beijing, China. We then evaluate the Cbudgets of these forest ecosystems. Our results indicated that total C density (organic C perhectare) of these forests ranged from 250 to 300 t C ha^(-1), of which 35—54 t C ha^(-1) fromvegetation biomass C and 209-244 t C ha^(-1) from soil organic C (1 m depth, including forest floordetritus). Biomass C of all three forests showed a net increase, with 1.33—3.55 t C ha^(-1) a^(-1)during the study period. Litterfall production, vegetation autotrophic respiration, and soilheterotrophic respiration were estimated at 1.63—2.34,2.19—6.93, and 1.81 —3.49 t C ha^(-1)a^(-1), respectively. Ecosystem gross primary production fluctuated between 5.39 and 12.82 t Cha^(-1) a^(-1), about half of which (46%-59%, 3.20-5.89 t C ha^(-1) a^(-1)) was converted to netprimary production. Our results suggested that pine forest fixed C of 4.08 t ha^(-1) a^(-1), whereassecondary forests (birch and oak forest) were nearly in balance in CO_2 exchange between theatmosphere and ecosystems.There is a general agreement that forest ecosystems in the Northern Hemisphere function as signifi-cant sinks for atmospheric CO2; however, their magnitude and distribution remain large uncertainties. In this paper, we report the carbon (C) stock and its change of vegetation, forest floor detritus, and mineral soil, annual net biomass increment and litterfall production, and respiration of vegetation and soils between 1992 to 1994, for three temperate forest ecosystems, birch (Betula platyphylla) forest, oak (Quercus liaotungensis) forest and pine (Pinus tabulaeformis) plantation in Mt. Dongling, Beijing, China. We then evaluate the C budgets of these forest ecosystems. Our results indicated that total C density (organic C per hectare) of these forests ranged from 250 to 300 t C ha-1, of which 35―54 t C ha-1 from vegetation biomass C and 209―244 t C ha-1 from soil organic C (1 m depth, including forest floor detritus). Biomass C of all three forests showed a net increase, with 1.33―3.55 t C ha-1 a-1 during the study period. Litterfall production, vegetation autotrophic respiration, and soil heterotrophic respira-tion were estimated at 1.63―2.34, 2.19―6.93, and 1.81―3.49 t C ha-1 a-1, respectively. Ecosystem gross primary production fluctuated between 5.39 and 12.82 t C ha-1 a-1, about half of which (46%―59%, 3.20―5.89 t C ha-1 a-1) was converted to net primary production. Our results suggested that pine forest fixed C of 4.08 t ha-1 a-1, whereas secondary forests (birch and oak forest) were nearly in balance in CO2 exchange between the atmosphere and ecosystems.

关 键 词：CARBON BUDGET CARBON density CARBON FLUX mountainous area TEMPERATE forest. 

分 类 号：Q948[生物学—植物学]