Diurnal and monthly variations of carbon dioxide flux in an alpine shrub on the Qinghai-Tibet Plateau

Continuous CO2 flux observation with eddy covariance method conducted in the alpine shrub on the Qinghai-Tibet Plateau indicates that there are distinct diurnal and monthly variations for CO2 fluxes in the alpine shrub on the plateau. As for diurnal variation, with net CO2 influx from 08:00 to 19:00 and net CO2 efflux from 20:00 to 07:00, peak CO2 flux during warm season (July) appears around 12:00 (-1.19 g CO2·m-2·h-1); there is no obvious horary fluctuation for CO2 flux during cold season (January), and horary CO2 flux during most hours in a day is close to zero except for a small amount of net efflux (about 0.11 g CO2·m-2·h-1) from 11:00-17:00. As for monthly variation, with net CO2 influx from June to September and net CO2 efflux from January to May and October to December, the peak monthly CO2 influx and CO2 efflux appear in August and April, respectively. The total net CO2 influx from June to September and total net CO2 efflux from February to May and October to December in the alpine shrub on the Qinghai-Tibet Plateau are estimated to be 673 and 446 g CO2·m-2. Results show that the alpine shrub on the Qinghai-Tibet Plateau is remarkable carbon dioxide sink under no grazing conditions and the total yearly CO2 influx is estimated to be 227 g CO2·m-2.

作 者： XU Shixiao ZHAO Xinquan LI Yingnian ZHAO Liang YU Guirui SUN Xiaomin CAO Guangmin   作者單位： XU Shixiao(Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, China;Graduate School of Chinese Academy of Sciences, Beijing 100136, China)

ZHAO Xinquan,LI Yingnian,ZHAO Liang,CAO Guangmin(Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, China)

YU Guirui,SUN Xiaomin(Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China) 

刊 名： 科學(xué)通報(bào)（英文版）  SCI 英文刊名： CHINESE SCIENCE BULLETIN  年，卷(期)： 2005 50(6)  分類號(hào)：   關(guān)鍵詞： alpine shrub   carbon dioxide flux   diurnal variation   monthly variation  

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