鹅掌楸致濒的生态因素研究

A study on the ecological factors of endangering mechanism of Liriodendron chinense (Hemsl.) Sarg

鹅掌楸（Liriodendronchinense（Hemsl．）Sarg．）为古老残遗植物，该属植物在第三纪曾广布于北半球。由于第四纪冰川的压力，现存中国鹅掌楸局限星散分布于被称作“避难所”的长江流域以南亚热带山地，其种群大小和结构，受到与其共存的优势树种的竞争压力及人为干扰等多方面因素影响。目前天然分布的鹅掌楸，其种群规模小，在原生境中往往种子饱满率偏低，尤其是位于分布区东部的种群，正处于非适宜的“濒危生境”中。如果物种陷入了因地质历史变化、种间竞争或其他灾难引起的“濒危生境”中，运用迁地保护手段，可有效地保护该物种。

Liriodendron chinense (Hemsl. ) Sarg. is an archaic plant native to eastern Asia. This genus was once widely distributed in the North Hemisphere in the Tertiary period.Because of the pressure from glacier movement in the Quaternary period, populations of L. chinense had been restricted in southern areas of Yantze River in so-called 'refuges'. Population size and structure are effected by different factors, such as, forest canopy density and artificial interference etc. According to the obvious character of the small populations with low viability of seeds, especially those located in the eastern part of its distribution area in China they are now really in a non-suitable habitat-' endangering habitat'. For species' falling into ' endangering habitat' caused by geohistorical changes, interspecific competition or other disasters, the ex situ conservation is especially important.