Floristic composition, diversity and vegetation structure of woody plant communities in Boda dry evergreen Montane Forest, West Showa, Ethiopia

摘要

This study was conducted on Boda Forest in West Showa Zone, Oromia National Regional State, west Ethiopia with the objective of determining the floristic composition, species diversity and the vegetation structure of the woody plant communities in Boda natural forest. Systematic sampling method was used to collect the vegetation data. Accordingly, 60 plots of 20 x 20 m (400 m2) quadrats were laid at every 50 m along five transect lines from south to north direction using compass. Vegetation parameters such as diameter at breast height (DBH), height and density of the study woody species were recorded, and all the collected vascular plant species were brought to National Herbarium of Ethiopia for identification. Vegetation classification was performed using R program Version 2.15.2 software vegan and labdsv packages. The Sorensens’s similarity coefficient and Shannon-Wiener diversity index were also used to detect similarities among communities and to compute species diversity and evenness between the plant communities, respectively. A total of 95 species belonging to 76 genera and 58 families were identified from the forest. The collected species were composed of 34.7% trees, 45.2% shrubs, 13.6% liana, 3% epiphyte, 1% trees/shrubs and 1% tree/liana. Five community types, Galiniera saxifrage-Maesa lanceolata, Juniperus procera-Myrsine Africana, Carissa spinarum-Helichrysum citrispinum, Osyris quadripartite-Rhus ruspolii and Acacia abyssinica-Gomphocarpus fruticosus were recognized from the hierarchical cluster analysis. Generally, the forest was dominated by the small sized trees and shrubs indicating that it is in the stage of secondary regeneration. The presence of strong anthropogenic disturbance in the area necessitates the need for an immediate conservation action in order to ensure the sustainable utilization and management of the forest.