A Study on Relationship between Biomass of Macrophytes and the Health Status of the Lake Ecosystem

Two ecological indicators, exergy (Ex) and structural exergy (Exst), and two ecological indexes, biodiversity and trophic state are calculated using the parameters of water quality and plankton investigated in five different ponds in Shandong province in China. The exergy and structural exergy are applied to evaluate the health state of ecosystems of the five ponds, whereas the biodiversity and trophic state are employed to make eutrophication assessment of the ponds. Via analyzing the relationships among the ecological indicators, the ecological indexes and the biomass of macrophytes, it is revealed that exergy, structural exergy and biodiversity is positive correlated to the biomass of macrophytes and that the trophic state decreases with the biomass of macrophytes. This result demonstrates that the ecosystems with more macrophytes can be regarded to hold better health state.