中国植树造林的非局地生物物理效应

植树造林通过改变陆-气之间的能量、动量和水分交换，既可以直接影响地面温度（局地生物物理效应），也可以通过大气的反馈作用间接影响地面温度（非局地生物物理效应）。过去的研究大多关注植树造林的局地效应，但是对植树造林的非局地效应研究较少，对该问题的认识存在很大的不确定性。中国在过去的40年里建设了一批以植树造林为措施的生态工程。本项目拟围绕中国区域植树造林的非局地效应开展研究。本项目将基于WRF模式，采用最新的方法甄别中国区域植树造林的非局地效应，并检验其不确定性；其次，结合动力学诊断方法和敏感性试验揭示影响中国区域植树造林非局地效应的关键陆面过程和大气反馈过程；然后，基于合成分析和不同增温情景的数值试验阐明气候背景的差异对植树造林非局地效应的影响。本项目的研究成果可以加深对中国区域植树造林非局地效应的认识，为中国建设生态工程提供科学建议。

Afforestation is able to modify energy, momentum and water exchanges between land and atmosphere, which can further impact surface temperature both directly (local biophysical effect) and indirectly through atmospheric feedbacks (non-local biophysical effect). Compared to the well-studied local effect, the non-local effect has been poorly investigated and remains a large uncertainty. China has implemented a series of ecological programs by afforestation in the last 4 decades. We therefore propose to investigate the non-local effect of afforestation in China. The non-local effect will be identified based on WRF model using a recently developed strategy, and the uncertainty of the non-local effect will be examined. Through both dynamic diagnostic analysis and sensitivity experiments using WRF model, we expect to reveal the dominant land process and atmospheric feedback regulating the non-local effect of afforestation in China. To illuminate the dependence of the non-local effect on the background climate, a composite analysis combined with scenarios-based numerical simulations will be performed. The results can help to improve our understanding of the non-local effect of afforestation in China, and provide scientific advices for the implementation of ecological programs by China.