Shrub Communities and Environmental Variables Responsible for Species Distribution Patterns in an Alpine Zone of the Qilian Mountains, Northwest China

• Published in: Journal of mountain science 2015, Vol.12 (1), p.166-176
• Main Authors: Huo, Hong, Feng, Qi, Su, Yong-hong
• Format: Article
• Language: English
• Subjects: Alpine environments; Biodiversity; Biogeography; Distribution patterns; Earth and Environmental Science; Earth Sciences; Ecological research; Ecology; Environment; Environmental conditions; Environmental factors; Geography; Mountains; Organic carbon; Plant ecology; Soil density; Soil pH; Spatial distribution; Species composition; Species richness; Topography; Vegetation; 中国西北地区; 物种丰富度; 物种分布; 环境变量; 祁连山; 空间分布格局; 高寒地带; 高寒灌丛
• ISSN: 1672-6316; 1993-0321; 1008-2786
• DOI: 10.1007/s11629-014-3126-x

Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the environmental factors that are responsible for the variations in species composition and richness of alpine shrublands using numerical methods. In the present study, we investigated vegetation and associated environmental variables from 45 sample plots in the middle Qilian Mountains of the northwestern China to classify different community types and to elucidate the species- environment relationships. We also estimated the relative contributions of topography and site conditions to spatial distribution patterns of the shrub communities using the variation partitioning. The results showed that four shrub community types were identified and striking differences in fioristic composition were found among them. Species composition greatly depended on elevation, slope, shrub cover, soil pH and organic carbon. The important determinants of species richness were soil bulk density and slope. No significant differences in species richness were detected among the community types. Topography and site conditions had almost equal effects on compositional variation. Nonetheless,a large amount of the variation in species composition remained unexplained.