草业科学2007，Vol.24Issue(9)：20-29,10.
青藏高原高寒草甸生态系统CO2交换量的"转折气温"
"Turning point air temperature" for alpine meadow ecosystem CO2 exchange on the Qinghai-Tibetan Plateau
摘要
Abstract
To understand the carbon dynamics and correlation between net ecosystem CO2 exchange and environmental conditions of alpine meadow ecosystem in the Qinghai-Tibetan Plateau, we analyzed two years (from 2002 to 2003) data measured by eddy covariance method. The results showed that in those two years the ecosystem behaved as the carbon sink and absorbed carbon dioxide 286.74 g/(m2·a) and 284.94 g/(m2·a),respectively. It suggested that there were not distinct correlations between the daily CO2 flux (net ecosystem exchange, NEE) and photosynthetic photon flux density (PPFD) and soil water content (SWC) while daily NEE was evidently corresponded to air temperature. The "turning point air temperature", was meant at that air temperature, when the increase rate of ecosystem photosynthesis (gross primary production, GPP) began to be above the increase rate of ecosystem respiration (Reco), and was 2.47 ℃ by an exponential-linear model established in the alpine meadow. Then, if the precipitation and PPFD doesnt change greatly, moreover, the alpine meadow keeps balance (not lots of variations among years, especially in plant species, plant growth), the capacity of alpine meadow ecosystem carbon sink will be enhanced when the increase of air temperature at above 2.47 ℃, and decreased when that of air temperature at below 2.47 ℃.关键词
CO2通量/高寒草甸/转折气温/青藏高原Key words
CO2 flux/alpine meadow ecosystem/turning point air temperature/the Qinghai-Tibetan Plateau分类
农业科技引用本文复制引用
张法伟,李红琴,李英年,赵亮..青藏高原高寒草甸生态系统CO2交换量的"转折气温"[J].草业科学,2007,24(9):20-29,10.基金项目
中国科学院知识创新工程重大项目(KZCX1-SW-01-01A) （KZCX1-SW-01-01A）
国家重点基础研究发展规划项目(2002CB412501) （2002CB412501）
