濒危植物长柄双花木(Disanthus cercidifolius var.longipes)的资源分布及濒危现状
Distribution and Current Status of the Endangered Shrub Disanthus cercidifolius var. longipes
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摘要: 通过广泛的野外考察,对长柄双花木(Disanthus cercidifolius var. longipes)10个自然居群和2个迁地保护居群进行了深入细致的调查记录,充分掌握了长柄双花木的地理分布和资源状况.调查结果表明,长柄双花木分布极为局限,资源贫乏,居群间彼此孤立.详尽阐述了各居群的生境状况、居群及群落特征,初步分析了该物种的濒危原因,认为长柄双花木特殊的生活史特性及种子仅靠蒴果开裂时的弹力传播,加上居群彼此孤立、缺乏相互交流,从而制约了该物种的自我繁衍及居群的扩张,这可能是其濒危的根本原因.另外,病虫害、自然灾害和人为干扰等外部因素也不容忽视.只有采取就地保护、迁地保护和回归引种三种措施相结合,才能对长柄双花木进行有效保护和科学管理.Abstract: Disanthus cercidifolius var. longipes is an endangered shrub endemic to China. Ten natural populations were investigated over the whole distribution area in order to explore its population and resource status, and two ex situ conservation populations were also surveyed in 2009 and 2010. Habitat status of each population and its community characteristics were described in detail based on field investigation. The reasons why this species is endangered were also explored. Results demonstrated that geographic distribution ranges were limited to several parochial areas, resources were very indigent, and populations were highly isolated from each other. Special life history traits of the species (i.e. reproductive biology problems) may impact self-reproduction. Seeds spreading only by elasticity from crazing capsules, together with poor mutual exchange among populations due to geographic isolation, may restrict population self expansion. These difficulties impact its endangered status. External factors such as plant diseases, insect pests, natural disaster and artificial disturbance cannot be ignored. In-situ and ex-situ conservation combined with reintroduction are effective measures for the protection and scientific management of D. cercidifolius var. longipes.