极危植物中甸刺玫的分布及种群数量动态

Distribution and Population Quantitative Dynamics of Critically Risked Rosa praelucens Byhouwer

中甸刺玫是云南香格里拉特有的极危植物和著名的高山花卉。通过对其分布及种群现状进行全面系统的调查,绘制了中甸刺玫的地理分布图及基于株高和冠幅的年龄结构图,编制了相应的种群静态生命表并绘制了相应的存活曲线。结果表明,除人工引种保存的69株个体外,中甸刺玫自然分布在香格里拉县小中甸镇沿硕多岗河的狭长型地带内,现有自然分布点44个,植株562株,其中幼苗61株。大多数分布地点仅有1至几株成年植株,几乎没有更新。个体数多的分布点中植株的表型变异较大,花型、瓣性和花色等丰富。中甸刺玫Ⅱ龄级至Ⅴ龄级的个体数较多,幼苗和老年个体较少,种群年龄结构在一段时间内比较稳定,但长远来说处于衰退状态。中甸刺玫的死亡率随着龄级的增加而增加,株高结构中存活数在Ⅱ龄级最高,冠幅结构中存活数则在Ⅲ龄级最高,随着龄级的增加存活数降低。

Rosa praelucens Byhouwer is a critically risked plant endemic to Shangrila County of Yunnan. It is also a famous alpine flower. The distribution and population status of R. praelucens was comprehensively and systematically investigated. The current natural distribution was then mapped. The age structure,life table and survival curve based on the height and crown of every plant was analysed. The results were as the follows： Except for the 69 individuals introduced and grown by local nurseries and companies,R. praelucens naturally distributed at a very long and narrow area along the Shuoduogang River around the Xiaozhongdian Town. It had totally 44 natural locations with 623 individuals,61 of which were juvenile plants. Most of the location had only one or several adult plants and no regeneration occurred. Phenotypic characters such as floral form,petal number and petal color varied much in those sites with more individuals. Most of the individuals concentrated in the age of Ⅱto Ⅴ in both height structure and crown structure,while both the younger and aged individuals were much less,showing that the population was stable in the next period of time,despite it would decrease in the long run. The mortality rate increased with the growth of age. The standard survival proportion was highest at age Ⅱin height structure and age Ⅲ in crown structure,respectively,then it decreased with the growth of age.