Diversity and community succession of macrophytes in Lake Changhu, Hubei Province

Abstract

在2011年的调查基础上,结合已有资料,研究长湖水生植物多样性、群落特征、水生植被分布现状及水生植物多样性的动态变化和群落演替规律,探讨驱动水生植物群落演替的主导因素.结果显示长湖现有水生植物95种,水生植物优势群落12个.与1985年相比,长湖水生植物无论是在优势种还是优势群落上均发生了巨大变化,从原来以沉水植物为主的优势群落逐步演替为以挺水植物+漂浮浮叶植物为优势的水生植物群落.同时水生植被分布面积急剧缩小,生物量显著下降,2011年全湖水生植被覆盖率仅为4.2%,单位面积平均生物量只有2001年的10%,全湖生物总量相比于2006年下降了88.5%.分析表明,大规模围网养殖等人为干扰活动及水体富营养化是致使长湖水生植物多样性显著下降和群落发生逆向演替的主要原因.;Based on previous results and data obtained from field investigation in 2011, the distribution of aquatic vegetation, species diversity and its dynamic changes, community characteristics and succession features of Lake Changhu were studied and the primary driving factors of community succession were analysed. Results showed that there were 95 species of aquatic plants and 12 dominant plant associations in Lake Changhu in the year of 2011. Compared with the results of 1985, both dominant species and preponderant associations changed dramatically. Dominant aquatic plant associations gradually varied from submerged macrophytes associations to the emergent and floating macrophytes. Furthermore, vegetation coverage of the whole lake declined dramatically to 4.2% and the mean biomass per m² decreased by 88.5%. Our analyses indicated that human disturbances such as large-scale seine farming activities and water eutrophication were main reasons for diversity reduction and adverse succession of Lake Changhu.