Woody Species Compositions, Diversity and structure of Kabo Lake (Bishan Waqa) Forests, Mengeshi District, Gambella Region, South West Ethiopia.

Abstract

Ethiopia is a country with a highly diversified climatic condition and topography which result in a wide range of habitats and vegetation types. This study was conducted on Kabo lake natural forest, Mengeshi District, Majang Zone, Gambella Regional states, southwest Ethiopia to determine floristic composition, diversity and structural analysis of the forest. Systematic sampling method was used to collect vegetation data from 40 plots (20m x 20m) for trees and shrubs. Structural parameters were analyzed by SPSS version 20. All the trees and shrubs with DBH>2.5cm and height ≥2 m were measured for height and diameter. Shannon - Wiener diversity index was applied to quantify species diversity and richness. Importance value index (IVI) for woody species was determined by summing relative density, relative dominance and relative frequency. A total of 41 woody species belonging to 35 genera and 21 families were recorded from Kabo lake natural forest. Of all the species recorded 28 (68.29%) were trees, 12 (29.27%) shrubs, and 1 (2.44%) woody climber. The most characteristics families dominating the area are Fabaceae by 4 (11.43%) genera and 5 (12.19%) species, Moraceae by 3 (8.57%) genera and 5 (12.19%) species. Ulmaceae contained 1 (2.85 %) genera and 2 (4.88%) species. The overall Shannon-Wiener Diversity Index (H`) and the evenness values for the entire forest were 2.77 and 0.75, respectively. The density of woody species in the forest decreases with increasing height and DBH classes. It has a density of 590.43 stems/ ha and a total basal area of 59.90 m2/ ha. The forest is characterized by high density of trees in the DBH <10 than in DBH > 70 Cm. The current study focused only on woody species. To have a complete set of information about the forest and to design a sustainable conservation strategy, further study on all aspects of the forest were recommended.