环太湖地区河道和湖泊沿岸带水生植物多样性现状调查

Investigation on the status quo of aquatic plant biodiversity in the riverways and littoral zones of the Lake Taihu rim

环太湖地区经济发达,人口密集,近年来面临严重的富营养化、生境退化和外来水生物种入侵等环境问题.为明确环太湖地区河道和湖泊沿岸带水生植物多样性现状,于2018年开展本地和外来水生植物多样性调查.结果表明:(1)在环太湖地区共计进行65个群落样方调查分析,记录到38种水生植物,分属22科29属;(2)环太湖地区31个河道样方中入侵沉水植物水盾草重要值最高,其次为另一种入侵漂浮植物凤眼蓝,在34个湖泊沿岸带样方中凤眼蓝重要值最高;(3)环太湖地区河道和湖泊沿岸带样方生物多样性分别随着水盾草和凤眼蓝盖度的增加而降低,表明外来入侵植物影响水生植物生物多样性.环太湖地区湖泊需加强防范凤眼蓝漂浮生长分布范围扩大和水盾草沿河道入侵太湖湖区.这一地区同时面对水生植物覆盖面积减少和外来植物入侵问题,建议进行全太湖流域水生植物分布区域和生物多样性摸底普查,加强对外来入侵植物传播的监控,建立水生植物自然保护区.

The Lake Taihu rim has a robust economy and a dense population.In recent years,this area is facing severe environ mental problems such as eutrophication,habitat degradation and invasion of introduced aquatic species.Aimed to clarify the status quo of aquatic plant bio diversity in riverway and littoral zone of the Lake Taihu rim,surveys on native and introduced aquatic plants were performed in this area in 2018.The results indicate that:(1)In total,38 aquatic plants species in 22 families and 29 genera were recorded in 65 community quadrats in the Lake Taihu rim in 2018;(2)An invasive submerged plant Cabomba caro liniana has the highest relative importance value(RIV)among 31 riverway quadrats,followed by an invasive free floating plant Eichhornia crassipes,and the latter one has the highest RIV among 34 littoral zone quadrats;(3)The aquatic plant biodiversity indices decreased with the increasing coverage of C.caroliniana and E.crassipes in riverway and littoral zone quadrats,respectively,indicating that the invasive plants had an impact on the biodiversity of aquatic plants.The expanding distribution of the free floating plant E.crassipes,and the possible invasion of the submerged plant C.caroliniana alongside river channels should be monitored in the Lake Taihu.Facing the problems of reducing coverage of aquatic plants and the invasion of introduced plants,it is recommen ded to conduct a full investigation on the distribution area and bio diversity of aquatic plants,enhance supervisory control on the spread of introduced species,and establish natural reserves on aquatic plants in the Taihu Basin.