藏东地区植物群落分布格局与环境因子的关系

Distribution pattern of plant communities and its relationship with environmental factors in eastern Xizang,China

认识山地植物群落分布及其与环境因子的关系,掌握物种多样性随环境因子的变化规律,能够为山地生物多样性保护和生态恢复提供科学依据.以藏东昌都地区植物群落为研究对象,在野外调查的基础上,通过层次聚类分析和冗余分析(RDA)对植物群落进行分类,分析群落分布与环境因子的关系,并通过线性回归分析物种多样性与环境因子的关系.结果显示,层次聚类将105个植物调查样方划分为7个群丛;RDA排序结果较好反映了藏东植物群落分布与环境因子之间的关系,决定区域植物群落分布的主要环境因子为海拔、坡向、坡度、土壤pH值和土壤速效磷含量(P<0.001);海拔、坡向和坡度对群落物种多样性有显著影响(P<0.01),而土壤pH值、土壤速效磷含量与植物群落物种多样性无显著相关关系(P>0.05).本研究表明藏东地区植物群落分布格局主要受地形和土壤因子的驱动,而影响物种多样性的关键因子是地形因子;上述研究成果有助于提高对区域生物多样性分布规律及驱动机制的认识,对藏东地区不同环境条件下生物多样性保护和受损植被的生态修复具有重要意义.

Understanding the distribution of mountain plant communities and their relationship with environmental factors as well as the variation in species diversity with environmental factors can provide a scientific foundation for the conservation and restoration of mountain biodiversity.This study examined the plant communities in the Changdu region of eastern Xizang,China.The vegetation community in eastern Xizang was divided using hierarchical cluster analysis based on field research.The relationship between the distribution pattern of the vegetation community and the environment was examined using redundancy analysis(RDA),and the relationship between species diversity and environmental factors was examined using linear regression.Hierarchical clustering revealed that the 105 plant survey samples were divided into seven associations based on the results.The RDA ordination results accurately reflected the relationship between the distribution of plant communities and environmental factors in eastern Xizang.Altitude,aspect,slope,soil pH,and soil available phosphorus content(P<0.001)were the primary environmental factors affecting the distribution of plant communities in this region.Altitude,aspect,and slope significantly affected species diversity(P<0.01),but soil pH and available phosphorus content did not(P>0.05).Topographic and soil parameters were the primary determinants of the distribution patterns of plant communities in eastern Xizang,whereas only topographic factors were the major determinants of species diversity.This study of plant community distribution and species diversity in eastern Xizang contributes to a better understanding of the distribution and driving mechanisms of regional biodiversity,which is crucial for biodiversity conservation and the ecological restoration of damaged vegetation under various environmental conditions.