Floristic composition of Doprar forest, Jekow district, Gambella National Regional State, Ethiopia

Abstract

The study was carried out at Doprar Forest, Southwestern Ethiopia to determine floristic composition and to identify community types in the study area. A total of 60 plots, 20 m x 20 m along horizontal distance were laid to collect the data on cover–abundance, DBH, height, and density for trees and shrub. The data on herbaceous species were collected from five, 1 m x 1 m subplots laid at four corners each and one at the center of the large plot. A total of 79 plant species belonging to 57genera and 32 families were identified. The five most dominant families were: Fabaceae 21 species, Combretaceae and Vitaceae are each represented by 5 species Commelinaceae and Convolvulaceae are each represented by 4 species. Four communities were derived from the PC-ORD by clustering the plots into groups, based on the abundance of the species. The name for each community type was given based on high synoptic values of tree and/or shrub species. Grewia mollis – Combratum collinum type community, Flueggea virosa – Acacia seyal type community, Ficus sur – Cadaba heterotrica type community and Acacia hockii – Cadaba heterotricha type community are the communities in Doprar forest. The study on vegetation and population structure showed that the density of tree species was high at the lower class levels. Tree density was 737.56 individuals per hectare and the basal area was 52.17m2/ha, frequency of all the tree species (762/ha) and the respective IVI values for each tree species were also calculated. The species with highest important value index was Ficus sur (27.61) followed by Ficus sycomorus (23.16). The comparison of Doprar forest with other forests in Ethiopia with respect to tree densities, percentage distribution of tree species, and basal area was done. Two general patterns of population structure were recognized, the J-inverted shape and bell shaped population structure.