湖北省原生台湾杉资源及其保护

台湾杉为国家二级重点保护野生植物,现间断分布于我国长江以南少数几个省市及缅甸北部。作者在野外调查基础上,分析了湖北省台湾杉的地理分布特点、母树资源现状、种群数量和结构、群落特征、濒危原因并提出了保护建议。结果表明湖北省共有野生分布的台湾杉约40株,约90%以上为胸径在25cm以上的大树,主要零星分布于星斗山保护区海拔750~1000m的沟谷或山坡;种群年龄结构极不完整,处于严重衰退过程之中;群落类型多样,次生性较强,反映了台湾杉是在人类的长期干扰下勉强生存的。导致台湾杉濒危的主要原因有历史时期气候变迁导致台湾杉分布区大幅度缩小和居群数量剧烈下降;台湾杉遗传质退化,种子发芽率低,天然更新能力差;残遗居群多为小种群,结构不合理,种群退化严重;人为干扰和破坏加速了台湾杉的灭亡。根据台湾杉濒危的原因和现状,建议加强对台湾杉原生居群和单株的保护,逐步恢复生境,改善种群结构。

Natural resources and conservation of Taiwania cryptomerioides in Hubei Province

Taiwania cryptornerioides, distributed disconnectedly in the south of Yangtze River and north of Myanmar, was catalogued as an endangered species and subjected to the second-ranking protection level in China. Based on the field investigation,the present resources situations of T. cryptornerioides in Hubei Province was analyzed in this paper, including the geographical distribution, population structure, community characteristics and threatened reasons. Some suggestions were put forward to protect it as well. The results showed that there are nearly 40 T. cryptornerioides trees distributed naturally in this region, 90% of which are big trees whose diameters are above 25 cm, and they distribute fragmentarily in the gullies and mountainsides that lie in elevation 750-1 000 m in Xingdoushan National Natural Reserve. Its population age structure is in bad conditlon,and community types are various and secondary. All these reflect that the T. cryptornerioides resources survived from the strong disturbance of human activities. The main causes of threat to the resources are the radical climatic changes in history resulting in a great decline of the population and a massive shrinkage of the distributions; degeneration of genetic germplasms;low germination rate of seed and bad natural regeneration potentiality;small,unhealthy population and disturbance from human activities. It is proposed that the protection of T. cryptomerioides should be strengthened by in situ conservation,recovering habitats gradually and improving population structure.