Abstract: In 2009-2010, bottom trawl surveys were conducted on the fish resources in Lake Taihu, aimed to understand the characteristics of fish community structure and diversity in the Lake. A total of 50 fish species were collected, belonging to 40 genera, 15 families, and 10 orders, among which, Cypriniformes had the largest species number, accounting for 68% of the total. The fish community was composed of three ecological guilds, and limnology species were most abundant (78% of the total abundance). The dominant species were of mini-type fish such as Coilia ectenes taihuensis, Hyporhamphus intermedius, and Salangichthys jordani. As compared with historical data, the fish species number in the Lake decreased, the composition of dominant species changed greater, and the mini-type fishes with body mass <30 g were absolutely dominant, with an obvious tendency of fish resources becoming smaller-scale. Due to overfishing and water pollution, the Margalef richness index D, Shannon diversity indices H′_N and H′_W, and Pielou evenness indices J′_N and J′_W in the Lake all decreased, being 1.54, 0.21, 0.46, 0.07, and 0.14, respectively. To some extent, the differences in the fish species composition and biodiversity reflected the adaption characteristics of the fishes to the environmental variables such as nutrients and transparency in the Lake.

Key words: Dabie Mountain, Pinus taiwanensis, tree-ring width, climatic response.