Comparative study of the net exchange of CO2 in 3 types of vegetation ecosystems on the Qinghai-Tibetan Plateau

• Published in: Chinese science bulletin Vol. 50; no. 16; pp. 1767 - 1774
• Main Author: ZHAO, Liang
• Format: Journal Article
• Language: English
• Published: Beijing Springer Nature B.V 2005; Northwest Plateau Institute of Biology, the Chinese Academy of Sciences, Xining 810001, China%National Institute for Environmental Studies, Tsukuba, Ibaraki 3050053, Japan%Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China%National Institute for Agro-Environmental Science, Tsukuba, Ibaraki 3058604, Japan
• Subjects: Carbon dioxide; Carbon sources; Comparative studies; Ecosystems; Grasslands; Kobresia humilis; Meadows; Vegetation; 二氧化碳; 生态系统; 青藏高原; Tibetan Plateau; net ecosystem CO2 exchange; eddy covariance method; Qinghai-Tibetan Plateau
• ISSN: 1001-6538; 2095-9273; 1861-9541; 2095-9281
• DOI: 10.1360/04wd0316

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.