广西海岸带天然林群落多样性及种间联结性

Community Diversity and Interspecific Association of Coastal Natural Forest in Guangxi

以广西东兴市竹山村滨海天然群落为对象,采用物种重要值(IV)、丰富度指数(S),Shannon-Wiener指数(H′)和Simpson多样性指数(D),Pielou均匀度指数(J_(sw))研究群落结构和物种多样性;采用方差比率法,通过基于2×2列联表对χ~2进行检验以及引入种间联结系数AC和共同出现率PC的方法,对乔木层的15个优势种群和灌木层的12个优势种群的种间联结性进行了研究。结果表明,S、H′和D均表现为灌木层>乔木层>草本层,三者变化趋势较为一致;乔木层J_(sw)最高,灌木层次之,草本层最低;乔木层主要种群总体上表现为负关联,灌木层则表现为正关联,均达到显著水平。不同的检验结果表明,乔木层主要树种间负相关的种对多,灌木层则相反,乔木层和灌木层植物种间联结性不显著的物种对较多,联结强度也不高,本区木本植物种对间独立性较强,在种间关系上表现松散。

15 tree species and 12 shrub species were selected to study interspecific associations by using variance ratio(VR) analysis and χ^2-tests,association coefficient(AC) and percentage co-occurrence(PC).The importance values(IV),richness index(S),Shannon-Wiener index(H′),Simpson diversity index(D) and Pielou evenness index(Jsw) were used to study the community structure and species diversity. Results showed that S,H′ and D were expressed as shrub layer > tree layer > herb layer,with the highest evenness of tree layer,shrub layer and lowest herb layer. The variation trend of species diversity index was consistent with the variation trend of richness index. The main population of tree layer showed negative correlation as a whole,while the shrub layer showed positive correlation. Both of them were significant. A tree layer was negatively correlated to occupy a great advantage whereas shrub layer presented the opposite result. Most species had non-significant correlations,which showed that the species of woody plants in this area were more independent and loose in the relationship between species.