Exergy and structural exergy as ecological indicators for the development state of the Lake Chaohu ecosystem

The Lake Chaohu is a typical shallow, eutrophic freshwater lake in China. This paper presents an attempt to apply exergy and structural exergy as ecological indicators to describe and measure the development state of the Lake Chaohu ecosystem, by demonstrating and analysing their relationships to trophic state, biodiversity, biomass and species composition. The findings for the Lake Chaohu ecosystem reveal that structural exergy has negative correlation to trophic state (r = −0.66) and positive correlation to biodiversity (r = 0.75); however, exergy has a strong positive correlation with biomass (r = 0.94). Therefore, it is concluded that exergy and structural exergy may serve as the ecological indicators to give the appropriate information on the development state of the Lake Chaohu ecosystem.