温带森林叶物候期决定了植被生长季长度，进而对陆地生态系统和大气系统之间的生物地球化学循环产生深刻的影响。全球气候变化已导致北半球温带森林春秋叶物候期发生明显变化，然而春秋叶物候对气候变化的响应机理目前还不清楚，模型模拟结果还存在较大的不确定性，这也是制约生态系统过程模式预测能力的重要原因之一。因此准确理解和模拟全球变化背景下中国温带森林物候变化具有重要的科学和现实意义。本研究将针对中国典型暖温带森林，开展野外控制实验，并结合植物生理观测，系统研究暖温带典型森林树种物候期对气候变暖的响应机理，阐明内部生理因子和外部环境因子对物候期发生的相对贡献率；结合近地面物候相机和无人机遥感、数据同化等方法，揭示物候从物种到植被水平的尺度转换机制，从而建立暖温带森林植被物候模型，并将该模型耦合入生态系统过程模式，以探讨中国暖温带森林对气候变化的响应以及物候波动对中国温带森林生态系统碳循环的影响。

The phenology of spring leaf out and autumn leaf senescence determines the length of vegetation growing season of temperate forests, and substantially influences biogeochemical-cycles between terrestrial biosphere and atmosphere. Recent studies have reported significant changes in phenology as a result of warming in most northern temperate regions, but the future evolution of the phenology of spring leaf out and autumn leaf senescence remains uncertain — in view of the imperfect understanding of how the underlying mechanisms respond to environmental stimuli, which is one of the important issues that limits the ability of dynamics global vegetation models on the prediction of the response of terrestrial ecosystem to climate change. Therefore, accurate understanding and predicting the dynamics of the leaf phenology under climate change is essential and have scientific and realistic importance. This project will study the mechanisms of the leaf out and senescence processes, and elucidate the relatively contribution of the internal physiological and external environmental factors on the phenology events, using field manipulative experiments and laboratory experiment. We further explore the scale transformation mechanism from species to ecosystem scale using webcams, lightweight unmanned aerial vehicles and data assimilation method, and then develop the vegetation phenology models and couple it into the dynamic global vegetation model to study the response of the Chinese temperate forest to the ongoing climate change and the effects of phenology dynamics on terrestrial carbon cycles.