Impact of Grazing Pressure on Woody Vegetation in Rangeland Ecosystems of Plateau State

Overgrazing in the rangeland ecosystems of north-central Nigeria has been consistently identified as a primary driver of woody vegetation decline and land degradation, with particular consequences for the mixed farming communities of Plateau State. This study assesses the impact of different grazing pressure intensities on woody plant species composition, density, cover, and regeneration in communal rangelands of three Local Government Areas in Plateau State. Grazing intensity was categorised as heavy, moderate, and light based on livestock density estimates from recent aerial surveys and corroborated by dung density counts along transects. Belt transects were established in each category, with woody plants measured for density, height, canopy cover, and reproductive status. Bare ground cover and soil surface condition were assessed as indicators of land degradation. Results indicate progressive decline in woody plant density and species richness with increasing grazing intensity, with heavily grazed sites showing 67% fewer woody stems per hectare compared to lightly grazed counterparts. Palatable browse species were virtually absent from heavily grazed sites, replaced by unpalatable and thorny species including Dichrostachys cinerea and Bauhinia rufescens. Woody regeneration was suppressed in heavily grazed areas, suggesting a threshold shift toward grass-dominated degraded states. Rotational grazing systems and community-managed grazing reserve agreements are proposed as restorative management frameworks. Keywords: grazing pressure, rangeland, woody vegetation, Plateau State, land degradation