Floristic composition, structure and regeneration status of Bengi forest in Gesha district of Kafa zone, Southwest Ethiopia.

backgroundBengi Forest, located in Southwest Ethiopia, is an ecologically important remnant forest known for its rich plant diversity and distinct vegetation patterns. Despite its ecological significance, the forest is under increasing threat due to farmland expansion, human settlement, and overgrazing. These pressures have led to significant degradation, highlighting the urgent need for detailed studies that evaluate the forest's floristic composition, structural attributes, and regeneration capacity.

methodsVegetation data were collected using a systematic sampling approach. Six transect lines were laid out across the forest in a west-to-east direction, spaced 200 m apart. Along these transects, 20 m × 20 m (400 m²) plots were established at 200-meter intervals to record data on trees and lianas. Each main plot contained five nested subplots (one in each corner and one at the center) to assess shrubs, herbaceous species, and the regeneration status of woody plants. Measurements of diameter at breast height (DBH), tree height, and species cover abundance were obtained using a tape measure, calibrated stick, and visual estimation, respectively. Species diversity and similarity between vegetation communities were evaluated using the Shannon-Wiener Diversity Index and Sørensen's Similarity Index.

resultsA total of 129 plant species representing 78 genera and 54 families were identified. The Fabaceae family showed the highest diversity, with 13 species, followed by Asteraceae (10 species) and Euphorbiaceae (9 species). The overall stem density was recorded at 2,041.33 stems per hectare. Syzygium guineense was the most frequently encountered species, present in 93% of the sampled plots. Macaranga capensis had the highest basal area (14.67 m²/ha), while Croton macrostachyus exhibited the highest Importance Value Index (IVI) at 18.62%. The Shannon diversity index for the forest was 3.8, with an evenness value of 0.87, indicating a relatively balanced species distribution. Three distinct plant community types were identified: (I) Schefflera abyssinica-Syzygium guineense, (II) Croton macrostachyus-Pouteria adolfi-friederici, and (III) Millettia ferruginea-Albizia gummifera. A high level of similarity (Sørensen's index = 0.89) was observed between community types I and II. Species with low IVI scores, such as Phoenix reclinata, Ficus ovata, Ehertia cymosa, and Dracaena steudneri, should be prioritized for conservation to maintain biodiversity and ecosystem stability.

conclusionThe forest exhibits a generally positive regeneration trend, suggesting potential for ecological recovery. However, selective cutting and uncontrolled grazing are causing notable ecological disturbances. These findings emphasize the need for targeted conservation strategies, including the promotion of alternative energy sources to reduce pressure on forest resources. Furthermore, future research should explore additional environmental variables influencing forest dynamics to inform comprehensive management approaches.