Candidate covariates included in the spatial models for 1995 and 2006.

(1)Digitized from Landsat images by the Department of Geography, University of Ghent (http://geoweb.ugent.be/sygiap/).(2)Database of the Central African Regional Program for the Environment (CARPE, http://carpe.umd.edu/).(3)Carpe Decadal Forest Change Mapping project (CARPE Decadal Forest Change Mapping (DFCM) Project, http://carpe.umd.edu/resources/dfcm) and South Dakota State University (Erik Lindquist).(4)Space Shuttle Radar Topography Mission (SRT Seamless Data Distribution System, Earth Resources Observation and Science (EROS), http://seamless.usgs.gov).(5)Obtained from Landsat 7 images (2002) and field data from transects and classified into the following ‘ecozone’ categories: mixed hill forest, rocky outcrops (inselbergs), savanna-forest ecotone, mixed forest, mono-dominant forest consisting of Gilbertiodendron dewrevei, swamp forest and non-forested area.