Understanding Global Vegetation Dynamics with Remote Sensing and the Coupled Carbon and Water Model
Conghe Song - Department of Geography
University of North Carolina at Chapel Hill
Abstract: Vegetation on the Earth’s land surface provides numerous key ecosystems services upon which the society’s welfare depends, such as provision of food and fiber, habitats for wildlife, soil and water conservation, and mitigation of global warming. Therefore, its dynamics have profound implications. In this talk I will present the most recent understanding of the temporal trend of global vegetation activities since 2000 when one of NASA’s key EOS instruments, the MODerate Imaging Spectroradiometer (MODIS), was launched. MODIS revolutionized our observation of the Earth. Based on the most recent release of the NASA MODIS Collection 6 data, Earth has experienced strong greening since 2000. However, this global greening does not necessarily lead to enhanced carbon storage. Using the remotely sensed data as input to the Coupled Carbon and Water model, we found that the trend in global Gross Primary Productivity (GPP) is much less stronger than the greening trend due to stress from climatic factors. Moreover, the majority of the greening happens in non-forest areas, particularly cropland where there is a limited capacity for carbon storage. The GPP for forest, which is the primary biome for carbon sequestration, in fact decreased mainly driven by tropical forest. Therefore, we cannot count very much on vegetation taking extra amount of carbon dioxide out of the atmosphere to meet the goal of Paris Agreement in slowing down global warming.
Biosketch: Dr. Conghe Song is currently a Professor and the Associate Chair in the Department of Geography at University of North Carolina at Chapel Hill. He obtained his PhD degree in Geography from Boston University in 2001. He has been working at UNC Chapel Hill since he finished his PhD. He got his Bachelor’s and Master’s degrees in forestry and forest ecology from Anhui Agricultural University in 1988 and Beijing Forestry University in 1991, respectively. He was a recipient of NASA’s New Investigator’s Program Award in 2006. He also spent a year at Harvard University as a Bullard Fellow during 2005-2006. His research interests include remote sensing of the environment, ecological modeling and human-environment interactions. He is particularly interested in understanding how land-cover/land-use changes influence ecosystem functions in the context of climate change through integration of remote sensing, ecological models and ground observations.