Shrub–Herb Plant Configuration Patterns and Their Relationship with Environmental Factors in the Northern and Southern Mountain Regions of Lhasa

This study explores shrub–herb configuration patterns in the northern and southern mountains of Lhasa and examines associations between slope aspect, soil properties, and plant community composition. By comparing plant communities on shady and sunny slopes (n = 15 plots), we found that shady slopes supported higher species diversity (Shannon index: 3.62 vs. 3.14) and more even distributions. Exploratory regression analyses suggested that soil moisture, salinity, and pH may be associated with the occurrence patterns of native woody species, though these relationships require validation with larger sample sizes. Principal component analysis identified several recurring shrub–herb associations, including Rosa sericea Lindl. with Cynoglossum amabile Stapf & Drummond and Argentina anserine (L.) Rydb., and Cotoneaster adpressus Bois with Taraxacum mongolicum Hand.-Mazz. and Carex myosuroides Vill. These associations exhibited higher co-occurrence frequencies across plots. Our findings provide preliminary guidance for shrub–herb configuration and ecological restoration in this region. This study offers baseline data and hypotheses for vegetation restoration, forestry greening, and ecological protection in the northern and southern mountain regions of Lhasa, though expanded research is needed to validate these exploratory patterns.