Woody Plant Species Diversity And Abundance In Gonbiso Natural Forest, Bore District, Guji Zone, Oromia Regional State, Southern Ethiopia

Abstract

Forest ecosystems provide numerous ecological services and economic benefits to many national economies in the world. Gonbiso Natural forest is one of the few remaining Evergreen moist Afromontane forests in the southern part of Ethiopia. Woody species diversity and abundance, species composition, structure and regeneration patterns of this forest were studied to generate information essential for formulating feasible management options for the forest. Vegetation data were collected from 50 quadrates of size 20 m x 20 m, 10 m x10 m and 5 m x 5 m for tree/shrub, sapling, and seedling, respectively, laid systematically along transects. A total of 62 woody species belonging to 55 genera and 40 families were recorded. Rosaceae with 4(10.8%) species each was the most diverse families, followed by Rubiaceae, Euphorbiacea, Rutiaceae, Araliaceae, Asteraceae and Oleaceae with three (8.1%) species each. Tree/shrub, sapling and seedling densities were 610.5, 872.5 and 1416 individuals/ha respectively. About 35.9% of the importance value index was contributed by Allophyllus abysinicus, Croton macrostachyus, Schefflera abyssinica, Syzygium guineense, Millettia ferruginea and Dombeya torrida. Vegetation classification resulted in four plant communities: Syzygium guineesse- Ricinus communis, Dombeya torrida- Scheffera abyssinica, Millettia ferruginea- Maytenus arbutifola, and Solanum incanum- Hagenia abyssinica. Regeneration status of all the woody plant species was categorized as ‘Good’ (19.4%), ‘Fair’ (38.7%), ‘Poor’ (17.7%), ‘None’ (22.6%) and ‘New’ (1.6%). The study is expected to provide valuable and adequate information that are essential for understanding the current situation of the forest.