Floristic composition, diversity and richness of selected Forest patches in Wombera district, Benshangul Gumuz Regional State, Ethiopia

Abstract

Floristic composition, diversity and community types of six forest patches in three agro-ecologies (higher, middle and lower) were studied in Wombera district, Benishangul Gumuz Regional State. Transect lines were laid 300m apart along altitudinal gradients; and plots were laid every 150m along the transect lines. Cover-abundance, height, DBH of woody plant species, and landscape variables were recorded in 142 (20× 20m) main plots. Seedlings and saplings were collected from five 5 × 5 m plots nested inside 20 × 20 m plots: four at corners and one in the center. Herbs and grass were collected from 1 × 1 m plots that were nested inside of 5 × 5 m plots, four at corners and one in center. Shannon diversity and Evenness indices were used to compute Floristic diversity and evenness. The Multivariate tool of R package (ver. 3.4.3) was used for community analysis. A total of 375 species representing 90 families and 70 genera were recorded from 142 plots in six forest patches within three agro-ecologies, of which 144 species were identified in higher altitudes, representing 52 families dominated by Asteraceae, Poaceae, Fabaceae, and Polygonaceae. In middle attitude, 115 species representing 49 families dominated by Fabaceae, Asteraceae, Poaceae, and Moraceae were identified. A total of 123 species were identified at lower altitudes, which represented 45 families, dominated by Fabaceae, Poaceae, and Combretaceae. The hierarchical classification analysis identified six communities, named after two or more indicator species. The plant communities are assembled by altitudinal gradients.