高山生态关键带植物群落多样性格局与系统发育结构

Diversity Pattern and Phylogenetic Structure of PlantCommunities in Alpine Ecological Key Zone

为探讨高海拔植物群落多样性海拔格局及其群落构建机制,本研究以生态过渡带布丹拉山南坡植被群落为研究对象。综合分析了物种丰富度、系统发育多样性、系统发育结构对海拔梯度变化的响应。研究结果:样方调查共记录了298种种子植物,隶属于45科149属。布丹拉山南坡种子植物物种丰富度与系统发育多样性和海拔相关性均不明显,但沿海拔梯度升高,Shannon-Wiener指数(H)、Simpson优势度指数(D)和Pielou均匀度指数(E)显著增大。Shannon-Wiener指数与其他物种多样性指数、系统发育多样性指数之间都显著正相关,系统发育结构指数与其他多样性指数无显著相关。布丹拉山南坡植物群落系统发育结构主体上表现为聚集,沿海拔梯度并无明显变化趋势。表明高山生态过渡带物种多样性和系统发育多样性与海拔关系都不显著,生境过滤的生态作用对植物群落构建起主要作用。

To explore the altitudinal patterns of high-altitude plant community diversity and their community-building mechanisms,this study selected vegetation communities on the southern slopes of the Budanla Mountain in the ecological transition zone.The responses of species richness,phylogenetic diversity,and phylogenetic structure to changes in elevation gradient were comprehensively analyzed.The results:A total of 298 seed plants were recorded in the quadrat survey,belonging to 45 families and 149 genera.The results of generalized linear regression analysis showed that there was no significant correlation between seed plant species richness and phylogenetic diversity and elevation on the southern slope of Budanla Mountain.However,the Shannon-Wiener index(H),Simpson dominance index(D)and Pielou evenness index(E)increased significantly with the increase of elevation.Shannon-Wiener index was significantly positively correlated with other species diversity indexes and phylogenetic diversity indexes.There were no significant correlation between phylogenetic structure index and other diversity indexes.In terms of phylogenetic structure,the phylogenetic structure of plant communities on the southern slope of Budanla Mountain had no obvious trend with the increase of elevation gradient,and the phylogenetic structure was mainly clustered.These findings suggest that both species diversity and phylogenetic diversity in alpine ecotransition zones are not significantly related to elevation,and that the ecological role of habitat filtering plays a major role in plant community construction.