海南三亚滨海雨林、半落叶季雨林到落叶季雨林的植物群落多样性及种间联结研究

为探索三亚沿海地区(自东向西)从滨海雨林过渡到半落叶季雨林、落叶季雨林的物种多样性及种间关系的变化趋势。该文采用植物群落学调查方法对三种植被类型进行群落调查,进一步使用物种丰富度指数(d GL)、Shannon-Wiener指数(H)、Simpson指数(P)和Pielou均匀度指数(E)来表征各植被类型的物种多样性水平,并使用联结系数(AC)、共同出现百分率(PC)及Spearman秩相关系数检验三种方法来表征各植被类型的种间关系。结果表明:(1)从滨海雨林过渡到半落叶季雨林再到落叶季雨林的生态序列变化过程中,森林优势物种组成逐渐由喜湿树种过渡为耐旱性较强的树种。(2)生物多样性的变化与降雨量呈正相关,均呈现自东向西逐渐递减。(3)三种植被类型共有物种的种间关系分析显示,三种植被类型种间关系松散,滨海雨林的种间联结强度相对较高,半落叶季雨林与落叶季雨林相似。综上结果认为,从滨海雨林到落叶季雨林物种间的协同共存关系在减弱,排斥竞争关系在增强;无论是物种组成、物种多样性水平还是种间关系,半落叶季雨林与落叶季雨林更相似。

Plant community diversity and inter-specific relationship of coastal rain forest,semi-deciduous monsoon forest to deciduous monsoon forest in coastal hills of Sanya City, Hainan Province

To explore the changing trend of species diversity and interspecific relationship of the forests in coastal hills of Sanya City(from east to west)from coastal rain forest to semi-deciduous monsoon forest and deciduous monsoon forest, the phytocoenological investigation methods were used to investigate those three types of vegetation communities in our field works. The species diversity in different types of vegetation were analyzed by the species richness index(d_GL), Shannon-Wiener index(H), Simpson index(P)and Pielou evenness index(E). The interspecific relationships in different types of vegetations were analyzed by association coefficient(AC), co-occurrence percentage(PC)and Spearman''s rank correlation coefficient test. The results were as follows:(1)Dominant species gradually changed from hygrophilous species to drought-tolerant species during the process of ecological sequence change from coastal rain forest to semi-deciduous monsoon forest and then to monsoon deciduous forest;(2)The change trend of species diversity was positively related to the annual precipitation, which decreased gradually from east to west;(3)Interspecific relationship of the three vegetation types was relatively loose; while the intensity of interspecific association in coastal rain forest was relatively high, and showed likeness between the semi-deciduous monsoon forest and deciduous monsoon forest. Those indicated that the co-existence of species was weakened from coastal rain forest to deciduous monsoon forest while the repelling competition was strengthened. In conclusion, the species composition, diversity and interspecific associations of semi-deciduous monsoon forest were more similar to those of deciduous monsoon forest.