Ecosystem health assessment of Lake Chao, a shallow eutrophic Chinese lake

Author:
Publisher website
Google Scholar
Abstract
Ecosystem health is a newly proposed concept that sets new goals for environmental management. Its definition, index and assessment methods are still being perfected. Eutrophication is a serious disease of lakes and reservoirs around the world that has badly damaged lake ecosystem health, and resulted in disharmony of ecosystem structure, and a decrease in biodiversity and resilience. In this case study for Lake Chao, an attempt to apply trophic state index (TSI), diversity index (DI), exergy (Ex), structural exergy (Exst) and phytoplankton buffer capacity β(TP)(phyto) to the assessment of the Lake Chao ecosystem health is presented. The results reveal that these indicators can give appropriate information on the state of health of the Lake Chao ecosystem. From January to March 1988, Ex, Exst, and DI are highest, the TSI and β(TP)(Phyto) are lowest. The lake ecosystem is relatively healthy; however, there are still some problems such as the disharmony of biological structure (too much zooplankton biomass and too little phytoplankton biomass). From August to October and from April to May 1988, the TSI and Ex are higher; and DI, Exst and β(TP)(phyto) are lower. This implies that the lake ecosystem is a typical eutrophic system, and lake ecosystem health is poor, especially in September and May. A relative order of state of health for the Lake Chao ecosystem from good to bad can be derived: January to March 1988 > November to December 1987 > June to July 1987 > April to May 1987 > August to October 1987. The results are in accordance with actual situations.

This publication has 18 references indexed in Scilit: