广西木论自然保护区掌叶木种群结构与分布格局

掌叶木(Handeliodendron bodinieri),是残遗于我国石灰岩地区的单种属特有种之一.因人为影响,生境特殊及自身特性,资源稀少,被列为国家一级重点保护野生植物.为了解掌叶木种群结构与动态以及空间分布格局特征,采用样地并结合无样地取样技术对掌叶木种群进行调查,绘制径级结构和高度级结构图、应用点格局进行分析,并采用Ripley's K(d)函数有效地描述种群空间属性.同时采用点到点距比率法进行格局计算.结果表明,掌叶木种群幼苗严重不足,种群呈衰退趋势;种群空间分布主要呈随机分布;掌叶木种群的分布格局受物种本身的繁殖特性、岩溶石山的生境特点以及种内种间的竞争等的共同影响.

Population structure and distribution pattern of Handeliodendron bodinieri in Mulun Natural Reserve, Guangxi

Handeliodendron bodinieri is an epibiotic single-species of plant unique to China in limestone regions. Because of destructive human activities, its peculiar habitat and its own characteristic, this rare species is endangered, and hence it has been listed as one of the first-level preservation plant species under state protection. Handeliodendron bodinieri population in Mulun Nature Reserve was investigated based on sampling plot and sampling line in order to clarify its population structure, dynamic character and distribution pattern. Size structure and height structure of Handeliodendron bodinieri population were analyzed. Point pattern analysis was applied and the spatial characteristics were described effectively by Ripley s K(d) function in this paper. The results showed that population of Handeliodendron bodinieri was declining due to lack of its seedlings, and distribution pattern of population was mainly random. Distribution pattern of Handeliodendron bodinieri population was primarily affected by the factors including its reproduction characteristics, habitat feature of limestone region, intraspecific and interspecific competition and so on.