Impacts of land use and land cover change on habitat connectivity: A case study of the Igando Igawa Wildlife Corridor, Southern Tanzania

Abstract

Habitat fragmentation and land cover change pose major threats to ecological connectivity and biodiversity conservation across sub-Saharan Africa. This study evaluates the impacts of land use and land cover (LULC) change on the structural connectivity and ecological function of the Igando-Igawa Wildlife Corridor (IIWC) in southern Tanzania, which links Mpanga Kipengere Game Reserve to Ruaha National Park. Using remote sensing, GIS-based modelling, ground surveys and field observations, we analysed landscape transformations over a 30-year period (1994–2024). Results indicate a substantial expansion of agricultural land with scattered settlements, increasing from 174.5 km² (19.3 %) to 475.9 km² (52.7 %). Bushland also expanded by 168.1 km², while woodland and grassland declined by 305.8 km² and 182.8 km², respectively. Built-up and bare land areas showed moderate growth. Landscape fragmentation intensified, with patch density increasing and the Aggregation Index declining from 93.11 to 81.70, indicating reduced core habitat. Least-cost path analysis revealed a narrowing and southward shift of the corridor, with cost-weighted distance rising from 161,549 to 242,407 units and path length extending from 52.9 km to 57.3 km. These changes have significantly impeded wildlife movement, particularly for large mammals such as elephants and lions, due to intensified human activities including agriculture, settlement expansion, livestock grazing and vegetation clearance. The findings highlight the urgent need for proactive corridor protection, integrated land use planning, and community engagement. This study has laid a foundation for further research and informs conservation strategies in rapidly changing landscapes.