PARENT SESSION
Contributed Oral Session 57: Polar and Alpine Ecology: Carbon and Nutrient Dynamics
Tuesday, August 9, 1:30 PM - 5:00 PM, Meeting Room 513 E, Level 5, Palais des congrès de Montréal

Carbon Dynamics of Major Ecosystems in the Tibetan Plateau.

Ouyang, Hua^*,1, Zhou, Caiping², Zhao, Xinquan, Zhang, Xianzhou, Cheng, Genwei, Luo, Tianxiang, ¹ Institute of geographical Sciences and Natural Resources, Chinese Academy of Sciences, Beijing, China² Institute of geographical Sciences and Natural Resources, Chinese Academy of Sciences, Beijing, China

ABSTRACT- The Tibet Plateau is the third polar of the earth. Its outstanding topographic feature and ecological characteristics cause significant effects on the atmospheric circulation and climate of surrounding areas and Asia, so the greenhouse gases emission and absorption are linked to climate changes at local, regional and perhaps global scales. In this paper, we observed the carbon emission and absorption in 4 ecological stations including Gonggashan, Haibei, Wudaoliang, Lhasa on the Tibetan Plateau by an open chamber method (1999-2001). The 4 eco-stations separately represent alpine forest, meadow, grassland and farmland ecosystems which are the key types of ecosystems in the Tibetan Plateau. The results showed that these four ecosystems are all carbon sinks. The TEM (Terrestrial Ecosystem Model) was used to estimate carbon and nitrogen dynamics in the natural ecosystems. We combined MODIS data and TEM algorithm to estimate NPP, soil carbon emission and carbon budget of the Tibetan Plateau, and calibrated the parameters with the field measurements. The mechanistic studies can improve our ability to model the Tibetan Plateau responses to global changes. The simulated results showed that the estimated total annual primary productivity of the Tibetan Plateau is 302×10¹² gC yr^-1, among which forest NPP takes up 39.7% of the total. NPP accumulation for summer is 246.7 ×10¹² g C yr^-1. The simulated soil emission of the major ecosystems is about 109×10¹² g C yr^-1. While the total carbon sink of the major ecosystems was 193×10¹² g C yr^-1.

Key words: Tibetan Plateau, alpine ecosystem, carbon dynamics