乌兰布和沙漠植物群落相异性及其影响因素

Plant community heterogeneity and its influencing factors in the Ulan Buh Desert

多样性反映群落间物种组成的相异性,是生态学研究的热点问题。通过对乌兰布和沙漠46个样地植物群落的调查数据进行分析,运用S?rensen相异性指数衡量该地区植物群落β多样性格局,并通过主成分分析、Mantel及Partial Mantel检验等方法来衡量各环境因子差异(包括气候和土壤)和群落地理距离对该区域植物群落β多样性格局的影响。结果表明:乌兰布和沙漠植物群落之间物种组成差异较大,物种周转(βsim)主导植物群落β多样性。气候因素、土壤因素和地理距离对植物群落β多样性及其周转组分有显著影响,物种周转对其响应与植物群落β多样性保持一致。乌兰布和沙漠植物群落物种在空间上的周转是环境限制和扩散限制综合作用的结果,环境过滤对植物群落β多样性及组分的影响超过扩散限制。

β diversity reflects the heterogeneity of species composition in communities,and is a hot topic in ecological research. In this study,we investigated plant communities from 46 sites in Ulan Buh Desert and used S?rensen heterogeneity index to measure β diversity patterns. Principal component analysis(PCA),Mantel and Partial Mantel tests were used to evaluate the effects of different environmental factors(including climate and soil)and community spatial distance on β diversity. The results showed that species composition differed greatly between ulan Bu and desert plant communities,and species turnover dominated the β diversity. Climate,soil and spatial distance had significant effects on β diversity and its turnover components,and the response of species turnover to β diversity was consistent with β diversity. The spatial alternation of plant species in Ulan Buh Desert is the result of the combined effects of environmental and dispersal limits,but the effects of environmental filtration on β diversity and composition exceed dispersal limits.