摘要
Using the eddy covariance method,from 1 July2003 to 30 June 2004, we conducted the observation andanalysis of ecosystem CO2 flux in 3 types of alpine meadowvegetation (Kobresia humilis, Potentilla fruticosa shrub andKobresia tibetica swamp meadows) on the Qinghai-TibetanPlateau. The results show that the Kobresia humilis meadow,the shrub meadow and the swamp meadow’s highest CO2uptake rates are 16.78, 10.42 and 16.57 μmol·m?2·s?1respectively, while their highest CO2 release rates are 8.22,7.73 and 18.67 μmol·m?2·s?1 respectively. The Kobresiahumilis meadow and shrub meadow’s annual atmosphericuptakes are 282 g CO2/m2 and 53 g CO2/m2, respectively,while swamp meadow’s annual atmospheric release is 478 gCO2/m2. This proves that the Kobresia humilis meadow andthe shrub meadow on the Qinghai-Tibetan Plateau haverelatively low potential for CO2 uptake and release comparedto C4 grasslands, a number of lowland grasslands, andforests. Moreover, swamp meadow has relatively high releasepotential. This, in turn, reveals clear differences in carbonsource/sink between different types of vegetation in theQinghai-Tibetan Plateau alpine meadow ecosystem. Thesedifferences are mainly brought by differences in thevegetations’ photosynthetic capacity and soil respiration.
Using the eddy covariance method, from 1 July 2003 to 30 June 2004, we conducted the observation and analysis of ecosystem CO2 flux in 3 types of alpine meadow vegetation （Kobresia humilis, Potentilla fruticosa shrub and Kobresia tibetica swamp meadows） on the Qinghai-Tibetan Plateau. The results show that the Kobresia humilis meadow, the shrub meadow and the swamp meadow＇s highest CO2 uptake rates are 16.78, 10.42 and 16.57 μmol·m^-2·-s^-1 respectively, while their highest CO2 release rates are 8.22, 7.73 and 18.67μmol·m^-2·-s^-1 respectively. The Kobresia humilis meadow and shrub meadow＇s annual atmospheric uptakes are 282 g CO2/m^2 and 53 g CO2/m^2, respectively, while swamp meadow＇s annual atmospheric release is 478 g CO2/m^2. This proves that the Kobresia humilis meadow and the shrub meadow on the Qinghai-Tibetan Plateau have relatively low potential for CO2 uptake and release compared to C4 grasslands, a number of lowland grasslands, and forests. Moreover, swamp meadow has relatively high release potential. This, in turn, reveals clear differences in carbon source/sink between different types of vegetation in the Qinghai-Tibetan Plateau alpine meadow ecosystem. These differences are mainly brought by differences in the vegetations＇ photosynthetic capacity and soil respiration.
基金
This work was supported by the Chinese Acad-emy of Science's Innovation Program(Grant No.KZCX1-SW-01-01A5)
the 973.Program(Grant No.2002cb4 125ol)
two joint Sino-Japanese projects:“Asia-Pacific Environmental Innovation Strategy Project(APEIS)"
"Research on the Effects of Carbon Dynamics and Global warming on Temperate Highland Grasslands”
关键词
青藏高原
植被
生态系统
二氧化碳
Qinghai-Tibetan Plateau, net ecosystem CO2 exchange,eddy covariance method.
