Forest cover and land use change trajectories within gazetted forest reserves in Nasarawa State, North Central Nigeria (1966–2020)

Abstract

The rapid losses of Protected Areas (PAs) and forest reserves has led to negative environmental, social, and economic impacts globally. This study examines land use and land cover change (LULCC) in Nasarawa State, North Central Nigeria, focusing on the timing and patterns of change in three gazetted forest reserves since 1966. Systematic and purposive techniques were used to select three forest reserves for the study, one in each of the state's geopolitical zones. Polygon maps of the three reserves from 1966 provided a baseline, against which a temporal sequence of Landsat remote sensing imagery was used to analyse historical trends of LULCC from 1986 to 2020. The analysis showed substantial degradation across all the reserves. Risha Forest Reserve experienced the highest loss, with 88 % of its forest cleared, largely due to cropland expansion (87 %). Doma Forest Reserve lost 83 % of its forest, with cropland covering 65 % of the area. Odu Forest Reserve had the lowest loss (55 %) and maintained 45 % forest cover by 2020. These significant losses pose severe threats to local biodiversity, increase greenhouse gas emissions, and exacerbate climate change impacts in the region. This study recommends the urgent assessment of current tree cover in gazetted forest areas, especially due to shifting agriculture. The government and forest communities should take steps for immediate and long-term sustainable forest management, monitoring reserves to preserve what remains and maintain conservation potential. Implementation of the 2020 National Forest Policy is needed to reduce rapid deforestation in north-central Nigeria so the development potential of managed reserves can be realised. Overall, the findings contribute to the understanding of deforestation trends in protected areas in Nigeria and West Africa more broadly, providing a valuable baseline for future research and policy development.