Abstract
Mountainous ecosystems provide social, economic, and environmental services at different scales. Nonetheless, currently, they have been exposed to environmental degradation risks. This study was conducted to investigate woody plant species diversity and threats to the study forest. Systematic sampling was employed to collect vegetation data from fifty 400 m2 sample plots along five transect lines. Vegetation and the environmental variables were recorded from each plot. Eighty randomly sampled households were selected for socioeconomic data. Descriptive statistics and ranking exercises were employed. The vegetation classification was performed using the R program version 2.15.2. The species diversity, richness, and evenness were computed. The result showed that five plant communities were recognized. A total of 99 woody plants belonging to 87 genera and 50 families were identified, of which 13 % were endemic. The total basal area of the study forest was 3.40 m2ha-1, and the forest was characterized by a bell-shaped population structure identified by poor regeneration and recruitment. With increasing altitude, there was a significant decrease in human impacts, grazing, and the number of plant species. About 90 % of the informants disclosed deforestation as the major threat to forest cover change, whereas 84 % of them recommended forest restoration as a tangible measure. There was a high deforestation rate of the selected woody species (e.g., Arundinaria alpina) and high expansion of agriculture at the fringes of the forest. This requires promoting forest land rehabilitation activities, nature tourism, establishing partnerships with communities on the forest management, consolidating village-level institutions and developing livelihood alternatives for communities at the local governments and the community level to restore the degraded forest.