FLORISTIC COMPOSITION AND STRUCTURE OF WOODY PLANT SPECIES IN SHONKOLLA MOUNTAIN FOREST, HADIYA ZONE, AT SOUTH ETHIOPIA.

Abstract

The study was conducted in Shonkolla mountain forest, to determine the floristic composition, structure and regeneration status of wood plant species. Five line transects were laid along altitudinal gradient. Vegetation data were collected from 52 quadrates’ of 20m x 20 m (400 m2) laid systematically along the line transects at every 50 m interval. Within, which the identity of all live woody species, and number of live individuals with diameter at breast height > 2cm were recorded in all sampled quadrates. The number of Seedlings, Saplings and Shrubs of each species were counted and recorded from 5 sub-plots of 5m x 5m laid one at each corner and one at the center of the big plot. A total of 43 woody plant species belonging to 36 genera and 29 families were identified in the study forest. Fabaceae was the dominant family of woody species in the study area. The collected woody species of the study forest was composed of 70 % of tree, and 30% shrubs. The Shannon diversity index and evenness of woody species of the entire forest were 2.94 and 0.97, respectively. A total basal area of the study forest was 42.9 m2/ ha-1 . Density of woody species of the study forest was 1591 (1225 trees and 366 shrubs) individuals ha 1 . The highest (20.34) importance value index (IVI) was recorded by Myrsine abyssinica. The population structure revealed an inverted J – shaped distribution in which the highest density in the lower DBH classes with subsequent decrement of densities of higher DBH classes. Density of seedlings and saplings of the study forest were 2163 ha-1 , and 1875 ha-1 respectivelly. Generally, the study forest had relatively high woody species diversity and good regeneration status but under increasing pressure of human interference. Thus management of natural forests largely depends on successful natural regeneration of valuable species. It is therefore imperative to develop and implement effective conservation measures to ensure sustainable utilization of the study forest.