生态系统呼吸温度敏感性的分布及影响因素

Distribution and Influencing Factors of the Temperature Sensitivity of Ecosystem Respiration

生态系统呼吸的温度敏感性(Q10)是表征气候变暖-陆地碳循环反馈作用的一个关键参数,然而其全球分布格局及其对关键环境因子变化的响应仍存在很大的不确定性。该研究基于全球199个站点的碳通量和气象数据,形成了一套全球生态系统呼吸温度敏感性的数据集。分析结果表明:全球生态系统呼吸Q10的平均值为(2.69±1.26),不同生态系统间存在显著差异,其中湿地的Q10值最高(3.37±1.62),灌丛最低(2.49±1.60)。除多树热带草原外,各生态系统的Q10值均随纬度的增加而增大,随年均气温、年降水量及饱和水气压差的增大而减小,这种差异与环境因子对Q10产生影响的阈值范围有关。研究结果突出了生态系统呼吸Q10的空间变异及对环境因子的响应在生态系统碳循环研究中的重要性,并建议在陆地碳收支研究中除了考虑Q10的总体变化还应兼顾不同生态系统类型间的差异。

The temperature sensitivity(Q10)of ecosystem respiration is a key parameter to characterize the feedback effect of climate warming on the terrestrial carbon cycle.However,its global distribution pattern and its response to changes in key environmental factors remain uncertain.Based on carbon fluxes and meteorological data from 199 sites around the world,this study developed a dataset of temperature sensitivity of global ecosystems respiration.The results show that average Q10 of global ecosystem respiration is(2.69±1.26),and there are significant differences among different ecosystems,the Q10 value of wetland is the highest(3.37±1.62),and snrubland have the lowest Q10(2.49±1.60).Except for the woody savanna,the Q10 values of each ecosystem increases with the increase of latitude,and decreases with the increase of annual mean temperature,annual precipitation and vapor pressure deficit,the difference is related to the threshold range of the environmental factors affecting Q10.The results highlight the importance of the spatial variability of Q10 of ecosystem respiration and its response to environ⁃mental factors in the study of ecosystem carbon cycle,and suggest that in the study of land carbon budget,not only the overall changes of Q10 but also the differences among different ecosystem types should be considered.