Effects of soil properties on vegetation community composition across a semiarid ecosystem

Identifying environmental factors that influence the vegetation community formation of various habitats in semiarid regions is imperative for managing these fragile ecosystems. The objective of this study was to quantify the relationships between selected environmental factors and vegetation community composition (VCC) in meadow and sand dune habitats using a structural equation model (SEM). Ecological data from 48 sample sites in semiarid sandy land were analyzed. The selected latent environmental variables included soil water (SW), topsoil salinity and sodicity, topsoil nutrients, topsoil texture (TT) and topography feature (TF). SW was the most influential factor for the Phragmites communis, Agriophyllum squarrosum, and Caragana microphylla communities composition. TT was the most influential factor for the Artemisia halodendron and Artemisia frigida - Agropyron desertorum communities composition. TF was the most influential factor for the Carex duriuscula and Phragmites communis - Bolboschoenus yagara communities composition. Considering the direct and indirect impact relationship, for the meadow habitat, TF was the primary factor causing the community distribution. For the sand dune habitat, TT was the primary factor causing the community distribution. As expected, the quantitative relationships between VCC and influencing factors differ depending on the ecological scales of interest.