海南岛濒危半红树植物莲叶桐Hernandia nymphaeifolia资源现状与种群动态特征

Resource Status and Population Dynamics of Endangered Semi-mangrove Plant Hernandia nymphaeifolia,Hainan Island, China

莲叶桐Hernandia nymphaeifolia为国家二级保护植物,本研究拟揭示濒危半红树植物莲叶桐在海南岛的分布规律与种群发展趋势,为其资源保护提供科学依据。研究采用样方调查法和直接计数法相结合的方法,调查了海南岛珍稀濒危半红树植物莲叶桐H.nymphaeifolia的资源现状、空间分布和种群动态特征。结果表明:海南岛共调查到野生莲叶桐1 336株,主要分布于琼海、文昌和三亚3个市,种群呈整体分散、局部集中状态,种群径级结构呈金字塔型;在人为干扰、地理隔离、种间竞争等多种因素的影响下,野生莲叶桐种群更新受到一定制约,个体数量增长缓慢;莲叶桐种群在幼苗时期受影响较大,一旦消除幼苗期的不利影响,种群将得到恢复。整体来说,海南岛莲叶桐幼龄个体数较多,种群数量具有前期锐减、中后期稳定、总体缓慢增长的特点,应重点加强幼苗期的保护和抚育。

Hernandia nymphaeifolia is a national class Ⅱ key protected plant.This study intends to reveal the distribution pattern and population development trend of the endangered semi-mangrove plant H.nymphaeifolia in Hainan Island, and provide a scientific basis for the protection of H.nymphaeifolia resources.The resource status, spatial distribution and population dynamics of H.nymphaeifolia, a rare and endangered semi-mangrove plant in Hainan Island, were investigated by using quadrat survey and direct counting method.The results showed that a total of 1 336 wild H.nymphaeifolia plants were investigated in Hainan Island, which were mainly distributed in Qionghai City, Wenchang City and Sanya City.The population presented a state of overall dispersion and local concentration.And the population diameter structure was pyramid-shaped.Under the influence of human disturbance, geographical isolation, interspecific competition and other factors, the population renewal of wild H.nymphaeifolia was restricted to a certain extent, and the number of individuals increased slowly.The population of H.nymphaeifolia was greatly affected at the seedling stage.Once the adverse effects of the seedling stage were eliminated, the population would recover.On the whole, the number of young H.nymphaeifolia individuals in Hainan Island is large, and the population has the characteristics of sharp decrease in early stage, stable in middle and late stage, and slow growth in general.The protection and tending of seedling stage should be strengthened.