Role of environmental variables on plant community formation in simien mountains national park afromontane vegetation

Abstract

Simien Mountains National Park, a UNESCO World Heritage Site, supports fragile Afromontane ecosystems, yet detailed information on its vegetation ecology remains limited. This study employed 139 stratified systematic sampling plots to characterize plant communities and examine relationships between vegetation and selected environmental variables. Plant communities were classified using hierarchical cluster analysis and plant–environment relationships were explored through ordination techniques. A total of 354 vascular plant taxa, representing 91 families, were recorded. Herbs constituted the dominant growth form (61.86%). Species richness was highest in Asteraceae (16%). Endemism was notable (12.2%), including seven species restricted to SMNP, underscoring the park’s national conservation importance. Cluster analysis identified four plant communities distributed along an elevational gradient of 2244–3150 m a.s.l. All communities exhibited relatively high diversity (Shannon index: 4.03–4.50; Fisher’s α: 25.4–35.1) and moderate compositional turnover (Jaccard similarity: 0.28–0.64), indicating substantial ecological heterogeneity. Canonical correspondence analysis showed altitude was the strongest environmental variable responsible for patterns of plant community formation, followed by soil properties, slope, and pH. Results demonstrate that SMNP supports rich species composition, endemism, and with spatial variation in vegetation composition. These findings provide a quantitative ecological baseline that can inform site-specific conservation planning and future monitoring.