MAPPING SPATIOTEMPORAL TRENDS IN THE ABUNDANCE AND DISTRIBUTION OF MACROPHYTES IN HONGZE LAKE

A comprehensive investigation on macrophyte community in Hongze Lake was conducted seasonally from May 2010 to February 2011. Overall, twelve species representing eight families of macrophytes were identified in Hongze Lake, including nine species of submerged plants, two species of floating-leaved plants, and one species of emerging plant. In general, Potamogeton malaianus, P. maackianu, P. pectinatus and P. crispus were the four dominant species throughout the whole year, the highest biomass of macrophytes was presented in autumn, followed by summer and winter, while spring had the lowest biomass of macrophytes. Based on field data, we used kriging interpolation in ArcGis to map the spatiotemporal distribution of the entire macrophyte community as well as each of the four dominant species. From the GIS maps we observed that the northern area of the lake, namely the Chengzihu region, had the highest biomass of macrophytes potentially as a result of better water quality and greater transparency. Potential factors that affected the community structure, biomass, and distribution patterns of macrophytes considerably were then discussed. The results of this study illuminate the need for more information on the role and importance of aquatic macrophytes in shallow lake ecosystems. Conservation of macrophytes should be taken to maintain the lake ecosystem health.