三峡库区消涨带特有植物疏花水柏枝(Myricaria laxiflora)的自然分布及迁地保护研究

Natural Distribution and Ex Situ Conservation of Endemic Species Myricaria laxiflora in Water-level-fluctuation Zone within Three-Gorges Reservoir Area of Changjiang River

疏花水柏枝为三峡库区消涨带特有植物,三峡工程的兴建将导致其野生居群全部灭绝。作者对该植物的地理分布、自然生境和群落结构进行了系统调查,发现疏花水柏枝分布于三峡库区重庆市巴南区至湖北省宜昌县间12个县级单位的长江干流消涨带,共31个居群9万余株,比原已知的分布区增加了7个县级区域18个居群8万余株。调查中发现该物种具有喜温湿、耐水淹和生长反季的生长习性,具有种子多、易扦插的繁殖优势和自然居群中物种少、水淹前后物种组成有差异的群落结构特点。同时,较系统地回顾了目前关于疏花水柏枝迁地保护的研究进展,探讨了其特殊的生态适应策略、起源进化和传播的可能途径以及濒危机制,并对下一步的保育研究提出了建议。

Myricaria laxiflora is a narrowly distributed species endemic to the water levelfluctuation zone within the ThreeGorges Reservoir Area of Changjiang River. The construction of ThreeGorges Dam will raise the water level, which will completely submerge the wild populations of the species. This paper updated information of M. laxiflora natural distribution by a recent survey that extensively collected data in its geographic distribution, natural habitat and community structure of the species. The data showed that a total of 31 populations of approximate 90000 plants were grown in alluvial strips along the Changjiang River in 12 counties from Chongqing to Yichang. New distributions in 7 counties were found in this survey, and 18 more populations, 80000 more plants investigated than that of previous studies. The species was also found to have several unique characteristics such as, warm climate and moisture loving, opposite seasonal growing (growing in winter), numerous seeded, easily clonal propagation by cuttings. There are only few other species in its natural community of M. laxiflora, and the species number and structure in the community varies according to the water level fluctuation. The paper also reviewed current research progresses in ex situ conservation for rescuing the species and discussed ecological adaptation, evolutionary history, possible spreading mechanism and causes of the species endangerment. Suggestion for further conservation of the species was proposed.