Divergence Of Water Yield And Gross Ecosystem Productivity Under The Changing Vegetation Cover And Climate In The Poyang Lake Watershed

Vegetation cover and climate are the major factors affecting water and carbon cycle and altering the ecosystem services, but their impacts on the coupling of water and carbon cycle are confounded at the watershed scale. This study aimed to quantify the impacts of vegetation cover and climate on two important parameters (gross ecosystem productivity (GEP) and water yield) in water and carbon cycle over the Poyang Lake watershed from 1984 to 2013. A modified Water Supply and Stress Index model (WaSSI) was used to address this issue through several scenario designs. The Poyang Lake watershed witnessed dramatic increases in vegetation cover, warming and drying trends. The preliminary results showed that increased vegetation cover with dry-warm climate could cause large decreases in water yield (< -6 mm yr(-1)) and increases in GEP (> 6 g m(-2) yr(-1)), respectively. The strong divergence of water yield and GEP mainly occurred in the cropland-dominated areas.