威宁草海的浮游植物(英文)

The phytoplankton in Caohai Lake, Weining

从2004年1月至2005年1月,对贵州威宁草海的浮游植物进行采集和鉴定,共鉴定出浮游植物390种(含变型和变种),分属7门10纲23目41科96属。其中绿藻门种类最多,达205种,占总种数的52.56%;其次是蓝藻门的种类,有85种,占21.79%;硅藻门的种类有55种,占14.10%;其他藻类有45种,占11.15%。全年均能采集到的有60种,多数为小型的、富营养湖泊种常见的水华藻类,如铜绿微囊藻(Microcystis aeruginosa)、铜绿微囊藻小型变种(M. aeruginosa var. minor)。鉴定出的藻类植物种有105种为污染指示种,其中全年出现的多污性(ps)指示种有6种,β-多污性(β-ps)指示种有44种,α-中污性(α-ms) 指示种有78种,β-中污性(β-ms) 指示种有64种,寡污性(os) 指示种有17种,分别占总污染指示种总数的5.71%,41.90%、74.29%、60.95%、16.19%(有的种类具有多种污染级别的指示,在统计过程中均分别计算),草海的污染指示种以α-中污染和β-污染指示种为主。根据草海浮游植物种类组成的历史演变来看,硅藻门的种类减少较多,其他一些适宜生活于清洁水体种的藻类,如小黄丝藻(Heterotrichales minus)从1989年以后就未曾发现。所有结果都显示出草海已受到严重污染,属于富营养型的湖泊。

Caohai Lake is situated at the Weining Yi,Hui and Miao Autonomous County of Guizhou Province. It lies in 104° 12′- 104° 18′ East longtude and 26°49′-26°53′ North latitude, and it is near the southwest part of Weining Township. Mean annual air temperrature is 10.5℃ （1.9℃in January and 17.7℃ in July）. Mean annual rainfall is 950mm. Caohai Lake is a typical and integrated karst plateau wetland ecosystem. It has become a national nature protect area for Grus nigricollis （Black-necked Crane） since 1992. It has been noticed widely as a important internationalwetland. Becouse it is located near Weining, wastewater was dischared into the lake. Indicative plants such as Alternanthera philoxeroides and Lemna minor appear at the sides of the lake close to the town .