Carbon dioxide exchange in a high‐arctic fen estimated by eddy covariance measurements and modelling
Carbon dioxide exchange in a high‐arctic fen estimated by eddy covariance measurements and modelling
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通过涡度协方差测量和建模估计高北极沼泽中的二氧化碳交换
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
C. Nordstroem
中科院分区：
文献类型：
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作者：
H. Soegaard;C. Nordstroem
高北极环境是全球变暖后果可能很严重的环境。在本文中，我们报告了格陵兰北部和东部国家公园的Zackenberg（74°28′N，20°34′ W）莎草占主导地位的沼泽上方的二氧化碳和水蒸气通量的研究结果。涡度协方差测量开始在生长季节的开始和结束前不久，持续45天。 白天的净CO2通量最高可达10 μmol m-2s-1，夏至前后，CO2净同化发生在午夜，导致夜间的净碳增加。 测量的二氧化碳通量比较以及Collatz等人的光合作用模型的基础上估计。 (1991 ).根据二氧化碳模型和微气象数据，生长季生态系统CO2净交换总量估计为96 g C m-2。 最后，结合CO2同化和土壤呼吸模式用于检查的二氧化碳收支对温度的依赖。生态系统的功能最佳的温度条件下，而无论是增加或减少温度将减少生态系统CO2的积累。温度升高5 °C将使生态系统变成二氧化碳源。
The high‐arctic environment is an environment where the consequences of global warming may be significant. In this paper we report on findings on carbon dioxide and water vapour fluxes above a sedge‐dominated fen at Zackenberg (74°28′N, 20°34′ W) in The National Park of North and East Greenland. Eddy covariance measurements were initiated at the start of the growing season and terminated shortly before its end lasting 45 days. The net CO2 flux during daytime reaches a high of 10 μmol m–2s–1, and around the summer solstice, net CO2 assimilation occurred at midnight, resulting in net carbon gain during the night. The measured carbon dioxide fluxes compare well to estimates based on the photosynthesis model by Collatz et al. (1991 ). The total growing‐season net ecosystem CO2 exchange was estimated to be 96 g C m–2 based on the carbon dioxide model and micrometeorological data. Finally, the combined CO2 assimilation and soil respiration models are used for examining the dependence of the carbon dioxide budget on temperature. The ecosystem is found to function optimally given the present temperature conditions whereas either an increase or a decrease in temperature would reduce the ecosystem CO2 accumulation. An increase in temperature by 5 °C would turn the ecosystem into a carbon dioxide source.