塔里木荒漠河岸林异质生境物种多样性比较与其测度指标筛选及评价

选择合适的物种多样性测度指标与多样性指数是进行群落多样性研究的基础工作。依据塔里木河上游荒漠河岸林样地调查资料，分别采用重要值、盖度和多度为测度指标比较了反映群落物种丰富度、多样性、均匀度和优势度12种多样性指数与异质生境群落多样性特征，并对多样性指数进行了相关分析与评价。结果表明，荒漠河岸林异质生境群落物种组成种类差异明显，轮南镇胡杨群落物种丰富度与多样性指数最高，水工三连灰胡杨群落多样性最低，土壤水盐的空间异质性是引起荒漠植被空间分布与群落多样性差异的主导因子。表征荒漠群落多样性以重要值和盖度为测度指标优于多度指标，其中以重要值为测度指标来反映群落多样性更为合理。相关与主成分分析表明，均匀度与多样性指数间的相关性高于丰富度与多样性指数，且多样性指数受均匀度、优势度指数受丰富度影响较大，反映出荒漠河岸林群落多样性主要决定于物种分布的均匀程度。12种多样性指数中Margalef丰富度指数（Ma）、Shannon-Weiner多样性指数（H）与Simpson多样性指数（D）能客观真实地反映异质生境荒漠植物群落多样性。同时，针对高度生境异质性的荒漠植物群落，还应综合考虑群落物种组成与生境特征，选择合适的多样性指数组合可更客观地反映荒漠河岸林群落多样性变化。

Comparison of Species Diversity under Heterogeneous Habitats,Determination and Evaluation of Diversity Indices of Desert Riparian Forest Community in Tarim Basin

The choice of diversity index and its measuring index are the basis in the species diversity of plant community. We studied the plant communities of desert riparian forest in the upper reaches of Tarim River. The species richness, diversity, evenness and dominance were compared by taking the important value, coverage and abundance with twelve measuring indices, and the characteristics of community diversity under different habitats were compared by using correlation analysis and principal component analysis. The community species compositions of heterogeneous habitats were significantly difference in desert riparian forest, P.euphratica community was the highest species richness and diversity index in Lunnan Town, P.pruinosa community was the lowest species diversity in three crop, and the spatial heterogeneity of soil water and salt was the main factor to determine the difference of spatial distribution and diversity of desert vegetation. The diversity indices based on important value and coverage had better than that of based on abundance, so the index of important value was more rational to reveal community diversity of desert plant communities. The correlation and principal component analysis indicated the correlation between evenness index and diversity index was higher than that of richness index and diversity index, diversity index was greatly influenced by evenness index, and dominance index was greatly influenced by richness index, indicating that the species diversity index of the desert plant communities was mainly affected by the even degree of species distribution. The Margalef richness index(M_a), Shannon-Weiner(H) and Simpson(D) diversity indices were be used to objectively reflect the diversity characteristics of desert plants community under heterogeneous habitats among twelve diversity index. At the same time, in view of the high habitat heterogeneity of desert plant community, and the community species composition and habitat characteristics were be considered, appropriate diversity index was selected and assembled to objectively reflect the characteristics of community diversity in desert riparian forest in Tarim Basin.