Analysis of Trophic Status and its Influence Factors of Different Water Body Types in Xixi National Wetland Park, China

An ecological survey was carried out to determine the water body concentrations of nutrients and its factors in Xixi National Wetland Park, China. According to the intensities of human activities, water body was classified into natural ponds, ornamental ponds, natural creeks and sight-seeing creeks. Based on calculated Trophic State Index (TSI), we can get conclusion that the trophic status of different water body types all exceeded the eutrophic level in the Xixi National Wetland Park. The natural creeks showed the highest TSI, followed by ornamental ponds, sight-seeing creeks and natural ponds, suggesting that natural creeks should be considered as priority sites for the implementation of water quality improvement. The main factors for trophic status in Xixi Wetland Park were discussed using canonical correspondence analysis (CCA) and multiple linear regression analysis (MLR). As a result, the trophic states in ponds were mainly controlled by hydrophyte cover. The trophic states in creeks made great relation to creek width and water quality of inflows. So we can find that human management can improve water quality by planting macrophytes of wetlands and controlling sewage water inflows from surrounding areas.