浙江省中华水韭分布现状与濒危原因

中华水韭(Isoetes sinensis Palmer)为水韭科水韭属多年生沼泽植物，现分布范围急剧缩小，种群数量稀少，处于濒危状态。通过查阅文献、标本，咨询专家学者，深入实地考察，访问产地农民，基本弄清了中华水韭在浙江省的分布情况及现有种群状况，结果如下：据记载，中华水韭在浙江省分布在杭州、诸暨、松阳、庆元、丽水、建德和天台等市、县。但仅查阅到杭州(1号)、诸暨(2号)和松阳(1号)3地共4号标本。实地考察仅发现在松阳有2个野生亚种群；杭州、诸暨和丽水野生种群可能已灭绝；杭州植物园、武汉植物园目前迁地保存有杭州种群；天台是否有中华水韭分布尚存疑问。松阳2个野生亚种群总面积约1000m2，分布在4块废弃的水田中，海拔约1110m，居群集中分布的面积不到300m2。中华水韭生存生境的人为直接破坏及水体污染，是其种群消失的主要原因。中华水韭残存种群在与禾草和灯芯草(Yuncus effuses)等主要优势种的竞争中处于劣势，在群落演替过程中，可能会被这些物种所取代，进而整个群落有可能被其他植被所取代，故现有的2个亚种群正处于濒危状态，亟待加强保护研究。

Distribution Status and Causation of Endangerment of Isoetes sinesis Palmer in Zhejiang Province

Isoetes sinensis Palmer (Isoetaceae) is an endangered swampy perennial.Seven wild populations were recorded in Zhejiang Province, but only two sub-populations were found in Songyang County,Zhejiang Province in this investigation.Habitat destruction and water pollution were considered two main causation of local extinction of this species.The total area of this two sub-populations were less than 1000 m2 and they were in endangered status.Their communities would be substituted by land communities in the process of vegetation succession.Some measures of conservation for this two sub-populations that should be taken were suggested.