五指山热带雨林黑桫椤种群及其所在群落特征  

Characteristics of Alsophila podophylla population and its community in the tropical rainforest in Wuzhi Mountains

作　　者：龙文兴[1] 杨小波[1] 吴庆书[1] 李东海[1] 郭涛[1] 

机构地区：[1]f海南大学生命科学与农学院热带生物中心,海口570228

出　　处：《生物多样性》2008年第1期83-90,共8页Biodiversity Science

基　　金：海南大学教育部热带海洋与陆生生物资源研究及利用重点实验室基金;海南省水务局项目--海南局部地区植被演变对水文特征的影响

摘　　要：黑桫椤(Alsophila podophylla)属国家二级保护植物。作者在海南岛五指山山地雨林和低地雨林分别设立样地对黑桫椤种群及其所在群落进行了调查,分析了热带雨林黑桫椤种群的年龄结构、空间分布格局、数量分布以及群落结构和物种多样性。结果表明,山地雨林和低地雨林中黑桫椤种群分别为稳定型种群和增长型种群,都是完全集群分布。低地雨林的黑桫椤平均密度是山地雨林的1.7倍。土壤pH值对黑桫椤种群密度有负的影响,全磷含量对其有正的影响。山地雨林林地土壤pH值大而全磷含量低,低地雨林刚好相反。土壤酸碱度和全磷含量的差异是导致两地黑桫椤数量差异的原因之一。pH值对黑桫椤平均密度的影响效应是全磷含量的2.5倍,说明pH值是影响黑桫椤种群密度的主要因素。黑桫椤所在群落垂直结构分为3个乔木亚层、2个灌木亚层及草本层。山地雨林黑桫椤所在群落的Simpson指数和Shannon-Wiener指数分别为0.957和5.305,均匀度为0.811;低地雨林黑桫椤所在群落的Simpson指数和Shannon-Wiener指数分别为0.937和5.484,均匀度为0.804。总之,五指山山地雨林和低地雨林的黑桫椤种群年龄结构、分布格局和数量分布都有一定差异,这些差异是由生境差异造成的。热带雨林黑桫椤所在群落结构复杂,物种多样性丰富。Alsophila podophylla is a second-class state-protected plant species. After surveying the populations and communities of A. podophylla in the lowland rainforest and the montane rainforest of Wuzhi Mountains, Hainan Island, we analysed the population characteristics including age structures, spatial pattems and quantities, and the community characteristics including structures and species diversity. The findings showed that A. podophylla population age-structures in the montane rainforest demonstrated a stable type while in the lowland rainforest it was growth-oriented, but the spatial pattems of both were clumped. The average population density of A. podophylla in the lowland rainforest was as 1.7 times as that in the montane rainforest. The soil pH value had negative effects on the average population density, and total P content in soil had positive effects on it. The soil pH value was high and the total P content was low in the montane rainforest, while the case was reverse in the lowland rainforest, hence the discrepancy of pH value and total P content between the montane rainforest and the lowland rainforest accounted for their quantity discrepancy of A. podophylla populations. Besides, according to their path coefficients, the effect that pH value caused to A. podophylla population density was as 2.5 times as that total P content did, thus it meant that soil pH value was the major factor that affected A. podophylla population density. All the commtmity structures were vertically divided into three tree layers, two shrub layers and one herb layer. The Simpson index, Shannon-Wiener index and evenness of the communities were 0.957, 5.305, and 0.811, respectively in the montane rainforest, while in the lowland rainforest they were respectively 0.937, 5.484, and 0.804. In conclusion, A. podophylla population of montane rainforest is different from that of lowland rainforest in characteristics including age-structures, spatial patterns and quantities, and in tropical forest of Wuzhi Mountains A. podophylla communi

关 键 词：Alsophila podophylla 热带雨林 群落结构 物种多样性 年龄结构 空间格局 种群数量 土壤 

分 类 号：Q948[生物学—植物学]