This study assessed the ground_flora diversity of the riparian forest of Omo Biosphere Reserve. It is stratified into three zones namely: Core Buffer and Transition. The Riparian forests along Major River and Streams were surveyed in the stratified zones and compared to the Upland vegetation. Stratified sampling was adopted and ninety plots (25 m × 25 m) were randomly assessed in the three strata of the study area. Sites were chosen based on accessibility within the zones and it was ensured that a variety of physiognomy was well represented. For each of the plots, the ground_flora was taken by measuring 5 m by 5 m sub plots from the corners of each plot and at the center. A total of 450 (5 m by 5 m) sub plots was used. The botanical name of ground_flora were identified, counted and recorded. Ground_flora species list was obtained, species abundance was determined and biodiversity of ground_flora was assessed through Species richness, Shannon-index (H) and Equitability index of Pielou (E). A total of 115 ground_flora species from 44 families were identified. The overall Riparian forest diversity of Ground_flora is 4.231. Ground_flora along streams had highest diversity index (4.01) and ground_flora in the upland vegetation had the highest abundance of 670 stand. Diospyros dendo is the most occurring species in all zones. Findings have important implications for improving ecosystem management.

Keywords: Biodiversity, Ground flora, Riparian Vegetation, Fragmentation