Reconstruction of Pre-Colonial Land Cover Baselines Using Historical Imagery and Remote Sensing for Conservation Planning in South West Nigeria

Defining appropriate conservation targets and restoration baselines requires understanding pre-disturbance ecological conditions, yet historical land cover data for West Africa rarely predate the mid-20th century. This study reconstructs pre-colonial land cover baselines for South West Nigeria using historical aerial photography from the 1940s and 1950s combined with contemporary remote sensing analysis. Digitised aerial photographs from the National Archive are georeferenced, orthorectified, and classified using semi-automated photointerpretation methods. These historical baselines are compared with Landsat-derived land cover maps for 1984, 2000, 2010, and 2022 to construct a century-scale land cover change record for Ogun, Ondo, and Osun states. Landscape configuration metrics quantify the spatial restructuring of forest cover from large contiguous patches to highly fragmented remnants. A theoretical framework for using pre-colonial baselines as aspirational targets for conservation and restoration planning is developed, distinguishing between achievable ecological reference conditions and historical wilderness ideals. Keywords: historical land cover, aerial photography, conservation baseline, South West Nigeria, forest fragmentation