当前位置: X-MOL 学术Nat. Clim. Change › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Light limitation regulates the response of autumn terrestrial carbon uptake to warming
Nature Climate Change ( IF 30.7 ) Pub Date : 2020-07-06 , DOI: 10.1038/s41558-020-0806-0
Yao Zhang , Róisín Commane , Sha Zhou , A. Park Williams , Pierre Gentine

Global warming is projected to shift the phenology and increase the productivity of northern ecosystems1,2,3,4,5,6. Both changes will further feed back to climate through biophysical and biogeochemical processes and are critical for future prediction7,8. However, it remains unclear whether warming and the extended growing season, especially in autumn, would lead to increased net ecosystem carbon uptake9,10. Here we analyse satellite observations, field measurements and model simulations and show a prevalent radiation limitation on carbon uptake in northern ecosystems, especially in autumn. By comparing the start and end of the growing season estimated from vegetation indices and from solar-induced chlorophyll fluorescence (a proxy for gross primary production11,12 (GPP)), we find a greater change in greenness-based start and end of season than that from GPP, mostly caused by the radiation limitation on photosynthesis. This radiation limitation explains the contrasting responses of autumn net carbon exchanges to warming, using both eddy covariance measurements and model simulations from Coupled Model Intercomparison Project Phase 5. Regions with weak radiation limitation benefit more from warming and enhanced vegetation greenness in autumn, where GPP increases can outweigh the warming-induced respiration carbon losses. With continued warming, radiation limitation will increase and exert a strong upper bound on northern ecosystems to act as carbon sinks.



中文翻译:

光照限制调节了秋季陆地碳吸收对变暖的响应

预计全球变暖将改变物候,并增加北部生态系统1,2,3,4,5,6的生产力。两种变化都将通过生物物理和生物地球化学过程进一步反馈给气候,对于未来的预测7,8至关重要。但是,目前尚不清楚变暖和生长季节的延长,尤其是在秋季是否会导致生态系统净碳吸收增加9,10。在这里,我们分析了卫星观测,野外测量和模型模拟,并显示了在北部生态系统(尤其是秋季)中普遍存在的辐射限制碳吸收。通过比较根据植被指数和太阳诱导的叶绿素荧光估计的生长期的开始和结束(代表初级总产量)11,12(GPP)),我们发现基于绿色的季节开始和结束的变化比GPP更大,主要是由于光合作用的辐射限制所致。此辐射限制使用涡度协方差测量和耦合模型互比较项目阶段5的模型模拟解释了秋季净碳交换对变暖的不同响应。辐射受限较弱的地区在GPP增大的秋天,由于温暖和增强的植被绿色度而受益更多可能超过变暖引起的呼吸碳损失。随着持续变暖,辐射限制将增加,并在北部生态系统上施加强大的上限,以充当碳汇。

更新日期:2020-07-06
down
wechat
bug