Integrated analysis of ecosystem service tradeoffs with ten-year land use changes to support water supply watershed protection

Background/Question/Methods: Land use change significantly affects the provision of multiple ecosystem services. Recent research on ecosystem service changes and tradeoffs has grown rapidly, but there is few understanding of the vulnerability mechanism of ecosystem service tradeoffs to land use change in diverse landscapes. We quantified the provision of 8 ecosystem services (crops, pork, surface water supply, carbon storage, biodiversity, soil retention, N and P retention) for 2000, 2005 and 2010 across Dahuofang Reservoir Watershed, a large water supply watershed of 417,100 ha, serving 23 million people. We used ArcGIS 10.1 software to analyze the spatial and temporal characteristics of multiple ecosystem service tradeoffs and their spatial correlation with land use change, aiming to protect water supply ecosystem service and maintain ecosystem multifunctionality. 

Results/Conclusions: Findings show that there were increases in services (crops, pork, biodiversity, surface water supply) and decreases in services (carbon storage, N and P retention) from 2000 to 2010, while a mix change existed in soil retention ecosystem service with little decrease during 2000-2005 and large increase during 2005-2010. Although there was a high spatial coincidence among spatial patterns of individual service across time, spatial distributions of high or low provision of multiple ecosystem services often varied with each other. At the watershed scale, all relationships among ecosystem services were synergies, while at the subwatershed scale, the tradeoffs occurred between ecosystem services of surface water supply and soil retention in Shehe Subwatershed. Across time, there was some heterogeneity in the magnitude of relationships among ecosystem services. Overall the results of this study will be applicable to scenario development combined with opinions from multiple stakeholders to improve protection planning in Dahuofang Reservoir Watershed.