Floristic Composition and Structural Analysis of Jibat Humid Afromontane Forest, West Shewa Zone, Oromia National Regional State, Ethiopia

Abstract

The study was conducted on Jibat Forest to determine the floristic composition, vegetation structure and plant community types. Systematic sampling method was used to collect vegetation data. A total of 74 quadrats each with a size of 20 m x 20 m for woody species and with in each major plot, five sub plots of size 1 m x 1 m were established for herbacious data collection. All plant species in each quadrat were recorded. Height and DBH of each woody plant species with height ≥ 2.5 m and DBH ≥ 2.5 cm were measured. A total of 183 species representing 161 genera and 73 families were recorded. Of the total species, 16 (8.74%) species are endemic to Ethiopia. Herbs had the highest composition followed by shrubs and trees. Six plant community types were identified from the cluster analysis and were named after 2 to 3 dominant species in each cluster. The description of each community type was given. The total basal area of the forest was 59.79 m²/ha. Analysis of importance value index indicated that Ilex mitis had the highest value (27.7). The study revealed the prevalence of small-sized individuals in the Jibat Forest. Six population distribution patterns were recognized, i.e., inverted J, irregular, U-shape, bell-shape, Gauss-type and J- shaped patterns. Therefore, based on the results of this study, detailed study on regeneration potential of the forest is recommended.

Key Words: Floristic composition, Jibat forest, plant community; vegetation structure.