Variations in ecosystem service values in response to changes in environmental flows: A case study of Baiyangdian Lake, China

Abstract

Environmental flows represent the quality, quantity and timing of water flows required to sustain the benefits provided to human, plant and animal communities by a healthy freshwater ecosystem. The precise characteristics of environmental flows can be difficult to define, however, and the precise impact of changes in these flows on the ecosystem service value (ESV) is likewise difficult to quantify. Using China's Baiyangdian Lake as a case study, I evaluated the ecosystem services provided by the lake from 1980 to 2005. The results showed that ESV was influenced by changes in the lake's environmental flows from its tributaries and revealed the potential relationship between ESV and water elevation. The ESV depended significantly on water elevation; thus, water elevation can be used as a proxy for changes in ESV and can provide guidance for effective environmental management. A sensitivity analysis revealed that the total ESV estimate for the study area was relatively inelastic based on changes in the coefficient of sensitivity (CS), and that the estimation was therefore robust. These results demonstrate that the relationship between ESV and water elevation is sufficiently strong and robust to help managers allocate water to balance the lake's environmental flows and ESV. © 2011 by the North American Lake Management Society.