DISTRIBUTION OF SUBMERGED PLANTS AND ITS RELATIONSHIP WITH ENVIRONMENTAL FACTORS IN GAOYOU LAKE

Gaoyou Lake is the sixth largest freshwater lake in China, it is located between Anhui Province and Jiangsu Province. It has been located in the eastern part of the South-to-North Water Diversion Project, playing an important role in the national water allocation strategy. Base on the investigation performed on the distribution of submerged plants in Gaoyou Lake in 2016, this paper analyzed the characteristics of distribution of submerged plants, and presented a relationship between submerged plants and key environmental factors with redundancy analysis. The results showed that there were few submerged plants in Gaoyou Lake. In addition, it was revealed that Potamogeton crispus was a dominant species and prevalent in the whole lake in late spring and summer seasons, which occupied all over the lake. Myriophyllum spicatum and Potamogeton pectinatus were only visible in few sampling points as well. Nitrogen (N) content of Gaoyou Lake maintained at Ⅲ level in different seasons, whereas phosphorus severely exceeded the limit. The correlation analysis revealed that the distribution of submerged plants was positively correlated with water transparency, while negatively correlated with total phosphorus (P) and ammonium. Results of Monte Carlo analysis also showed that both the total phosphorus and water transparency were the main environmental factors playing key roles in the distribution of submerged plants in Lake Gaoyou. These results have provided a strong basis for utilization and protection of submerged plant resources in Gaoyou Lake.