Floristic Composition, Vegetation Structure and Regeneration Status of Kimphe Lafa Natural Forest, Oromia Regional State, West Arsi, South East Ethiopia

Abstract

Scientific study on floristic composition, vegetation structure and regeneration status of a forest is needed for understanding of forest status to take appropriate conservation measures based on the outcome of studies.This study was conducted on Kimphe Lafa natural forest, which is Dry ever green montane Forest, located in Arsi Negele woreda, West Arsi Zone, Oromia Regional State southeast Ethiopia. The objective of the study was to assess floristic composition, vegetation structure and regeneration status of Kimphe Lafa Natural forest. Systematic sampling method was used to collect vegetation data from one hundred thirty four plots which were 20 m x 20 m for woody plant species and within a plot, 5 m x 5 m was used for seedlings and saplings and 1 m x 1 m was used for herbaceous plants. The sampling plots were placed at every 200 m intervals along the seventeen transect lines laid at 200 m a part. The vegetation analysis was performed using PC – ORD software package. A total of 130 plants species belonging to 100 genera and 56 families were recorded and identified. Fabaceae was the most dominant family represented by eighteen species followed by Asteraceae with ten species and Euphorbiaceae with six species. Six plant communities: Vernonia urticifolia-Croton macrostachyus, Calpurnia aurea-Maytanus abuscura, Ficus sur-Podocarpus falcatus, Justicia schimperiana-Dodonaea angustifolia, Ehretia cymosa- Pterolobium stellatum and Maytanus arbotifolia-Caucanthus auricalatus were recognized. The densities for mature woody species, seedlings and saplings were 515.7, 1091.8 and 834.7 individuals ha-1 respectively. The basal area of the forest was 114.4 m2 ha-1. Both seedling and sapling of plant species like Ximenia americana, Cordia monoica, Cussonia arborea and Rhus glutinosa were totally absent from the area. The plant species of the forest were prioritized for conservation using population structure and important value indices. Phytogeographical comparison was made among some forests of Ethiopia and Sorenson’s similarity coefficients were below 0.5 for all forests in comparison, indicating the presence of low similarities among the forests. The population structure and regeneration status of the forest indicated that there are anthropogenic disturbances in the area and immediate conservation actions have to be implemented for sustainable utilization of the forest. Key words/Phrases: Kimphe Lafa Natural Forest, Dry ever green montan forest, floristic composition, plant community, population structure, phytogeographical comparison, regeneration, Floristic composition, Vegetation structure