唐昊——遥感科学国家重点实验室2018年系列学术讲座之四
来源: 黄华兵
被阅读 329 次
2018-01-23
报告题目:Lidar observed seasonal variation of vertical canopy structure in the Amazon evergreen forests 
 
报告人:唐昊 (马里兰大学)
 
邀请人:黄华兵 副研究员
 
时间:2018年1月26日14:00-15:30  
 
地点:中科院遥感地球所(奥运园区)A504
 
报告人简介:唐昊,美国马里兰大学Assistant Research Professor,主要研究方向是基于Lidar的陆地生态系统三维遥感观测,是NASA新一代全球对地生态系统观测激光雷达Global Ecosystem Dynamics Investigation (GEDI)的Science team核心成员。在顶级期刊如美国国家科学院院刊(PNAS)上以第一作者和通讯作者发表十余篇文章。
 

报告摘要:Both light and water are important environmental factors governing tree growth. Responses of tropical forests to their changes are complicated and can vary substantially across different spatial and temporal scales. Of particular interest is the dry-season greening-up of Amazon forests, a phenomenon undergoing considerable debates whether it is real or a “light illusion” caused by artifacts of passive optical remote sensing techniques. Here we analyze seasonal dynamic patterns of vertical canopy structure in the Amazon forests using lidar observations from NASA’s Ice, Cloud, and and land Elevation Satellite (ICESat). We found that the net greening of canopy layer coincides with the wet-to-dry transition period, and the net browning occurs mostly at the late dry season. The understory also shows a seasonal cycle, but with an opposite variation to canopy and minimal correlation to seasonal variations in rainfall or radiation. Our results further suggest a potential interaction between canopy layers in the light regime that can optimize the growth of Amazon forests during the dry season. This light regime variability that exists in both spatial and temporal domains can better reveal the dry-season greening-up phenomenon, which appears less obvious when treating the Amazon forests as a whole.