红豆杉迁地保护中天然种群的形成

Establishment of a natural population during the ex situ conservation of Taxus chinensis

０年代自庐山植物园引种栽培于南京中山植物园的１１株红豆杉〔Ｔａｘｕｓｃｈｉｎｅｎｓｉｓ（Ｐｉｌｇｅｒ）Ｒｅｈｄ．〕幼苗组成的栽培种群，在４０多年的迁地保护过程中，生长发育正常，且在邻近的自然生境中繁衍出一个含有４６１株幼苗及小树的天然红豆杉种群，树高１０～３４５ｃｍ，树龄１～１５年，主要散生于海拔３５～６０ｍ的山坡麻栎群落及山溪边的枫杨群落中。栽培种群中雌树５株，雄树６株，栽培红豆杉在３０年左右开花结实。该天然种群的形成过程是：红豆杉成熟种子被鸟类取食，其肉质假种皮被消化后，在鸟类的栖息范围内随着鸟粪被随机散布，经过生境选择、适应，于适宜的生境条件下萌发生长成幼苗及小树。此外，讨论了天然红豆杉种群的形成和发展，对于植物迁地保护研究与实践的重要意义。

Eleven seedling trees of Taxus chinensis (Pilger) Rehd. including 5 females and 6 males, introduced from Lushan Botanical Garden and cultivated as a group in Nanjing Botanical Garden in 1950s, has growed and well developed. Furthermore, it has brought about a natural population of Taxus chinensis by 1997, which consists of 461 individuals 10～345 cm tall and aged 1～15 years. This natural population mainly scatters in community of Quercus acutissima Carr. on mountain slope or in community of Pterocarya stenoptera C. DC. beside mountain stream at 35～60 m altitude. The cultivated Taxus chinensis began to bring forth seeds at about 30 years old. The process of establishing the natural population is elucidated as follows: ripen seeds were ingested by some kinds of birds, then through birds′ faeces containing the seeds with their fleshy arils digested, they were dispersed in a random way within the boundary of areas where birds lived or perched. After withstanding adaptive selections of their habitats, parts of the dispersed seeds could germinate to give seedlings. In addition, some considerations on the research and practice of plant ex situ conservation are given.