Effects of livestock grazing on herbaceous species composition and biomass in the Simien Mountains National Park, Ethiopia

Abstract

Abstract Simien Mountains National Park (SMNP) provides valuable ecosystem services. Despite its ecological values, the effect of livestock-free grazing on habitat quality has not been investigated. The present study aimed to examine how livestock grazing within the Simien Mountains National Park affects herbaceous plant diversity and biomass. The study was carried out from February 2019 to July 2019 in livestock-grazed and ungrazed sites. In each grazing site, ten transects with a length of 25 m were set monthly. Along each transect line, five temporary sample plots (1 m 2 ) were established. For aboveground biomass estimation, grass and forbs were clipped from 0.25 m 2 in every sample plot, whereas below-ground biomass was estimated from two soil core (diameter = 6.35 cm, depth =20 cm) samples in each transect. Species diversity and evenness were estimated using the Shannon-Wiener diversity and evenness index. A total of 43 plant species belonging to 20 families were identified. Aboveground biomass and below-ground biomass were significantly higher in ungrazed areas than in the grazed ones. Similarly, species diversity and richness were relatively lower in the grazed areas than in ungrazed areas. The study concluded that livestock grazing has affected the habitat by degrading the vegetation diversity and biomass production. Therefore, stakeholders should be encouraged to innovate appropriate grazing management technologies for the local livestock ranchers to support the conservation efforts of the park.