Mitsuru HIROTA¹, Yuichiro YASHIRO², Yoko SHIZU², Toshiyuki OHTSUKA², Mingyuan DU³, Yingnian LI⁴, Yanhong TANG⁵

¹Graduate School of Life and Environmental Sciences University of Tsukuba, Japan

²Institute for Basin Ecosystem Studies, Gifu University, Japan

³National Institute for Agro-Environmental Sciences, Japan

⁴Northwest Institute of Plateau Biology, CAS, Xining, China

⁵National Institute for Environmental Studies, Japan

Alpine grasslands in East Asia extend around very high altitudes, such as the Qinghai-Tibetan Plateau. The ecosystems have received increasing attention in light of recent environmental changes, i.e., global warming and human activities which show dramatic change along with altitude. To depict the effects of environmental changes on alpine grasslands, it is needed to understand the current carbon dynamics of the grasslands along different altitudes. We conducted chamber-based measurement of ecosystem CO₂ flux, NEE, ecosystem respiration (ER), and GPP in a in an alpine meadow from 3200 to 4200 m along a slope of the Qilian Mountains on the Qinghai-Tibetan Plateau during the growing season of 2007 and 2008. Our results showed that under current environments, lower altitudes have smaller NEE due to lower vegetation biomass with high ER and higher grazing intensity compared with higher altitudes.