Macrophyte Succession in Dianchi Lake and Relations with the Environment

Abstract

通过滇池水生植被和水体污染状况的全面调查(1995-1997年),揭示了水生植被的演替动态与环境质量变化的关系结果表明,滇池现有水生植物22种,以凤眼莲(Eichhornia crassipes)、喜旱莲子草(Alternanthear Philoxeroides)、龙须眼子菜(Potamogeton petinatus)和聚草(Myriophyllum spicatum)等为优势种,其水生植被可划分为 9个群丛.与历史资料比较表明, 40年来,滇池的水生植被面积从 20世纪 50-60年代的 90%下降到 1996年的 1.8%,生物量由过去的1363.1gm^-2(鲜重)下降到1367 gm^-2.群落结构迅速简化和退化,原来的优势物种如海菜花、轮藻等已绝迹,菹草、马来眼子菜、苦草等已到濒临消失的边缘,耐污种如凤眼莲、喜旱莲子草和龙须眼子菜等大发展.;The investigation of the aquatic vegetation in Dianchi Lake has been carried out from 1995-1997.This paper described the sepcies composition, community structure, distribution, biomass and succession dynamics of aquatic vegetation in the Lake, and analyzed the interaction between the change of the aquatic vegetation and the environmental quality.Comparing with over 100 species found in the 1950s in Dianchi Lake, there are only 22 sepcies of auqatic vascular plants collected from this lake, among which Eichhornia crassipes, Alternanther phiLoxeroides, Pota-mogeton malainus and Myriophyllum spicatum are the dominant species off aquatic vegetation.The aquatic vegetation of Dianchi Lake from 1995 to 1997 could be divided into 9 associations.Due to the eutrohpication and the water pollution, the area of the aquatic vegetation decreased from 90% to 1.8% and the biomass decreased from 1363.1 g m^-2 to 136.73 g m 2during tl.last 50 years.The community structure has simplicated and deteriorated drastically, the biodiversity changed periodcally along with the succession of the major species.The Dianchi Lake has completed the transition from submerged-plant-dominant-type, and Caohai has being in the third alternative stable state which the floating plant is dominant.