THE COMMUNITY ECOLOGY OF AQUATIC PLANT IN THE WATER-LAND ECOTONE OF LIANGZI LAKE

The feature and the structure of plant communities were measured and the life form spectrum and the growth form spectrum of the communities in the water-land ecotone of Liangzi Lake were analyzed. Nine types of communities were described: 1) Ass. Potamogeton maackianus; 2) Ass. Myriophyllum spicatum, Vallisneria natans, Ceratophyllum demersum; 3) Ass. P. maackianus, C. demersum, M. spicatum; 4) Ass. C. demersum, P. maackianus; 5) Ass. C.demersum, M. spicatum, Nymphyoides peltatum; 6) Ass. Polygonum hydropiper, Trapa bispinosa, Zizania latifolia ; 7) Ass. Potamogeton crispus ; 8) Ass. Z. latifolia, N. peltatum, P. hydropiper; 9) Ass. Helophyte .The biomass of four dominant submerged communities was analyzed as follow: Ass. M. spicatum, V. natans, C. demersum; Ass. P. maackianus, C. demersum, M. spicatum; Ass. C. demersum, P. maackianus; Ass. P. maackianus was 2414 g·m -2, 4379 g·m -2,1486 g·m -2, 2805 g·m -2 respectively. The seasonal changes in the biomass of the main communities were the results for their growth patterns and human interference, and different species showed its own feature. The distribution of species was independent from each other and the distribution patterns of almost all species were contagious.