1. Department of Geography and Planning, Faculty of Arts, The University of Bamenda P.O. Box 39, Bambili, NW Region, Cameroon
2. School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa
3. South Africa National Biodiversity Institute, Free State National Botanical Garden, Rayton, Dan Pienaar, PO Box 29036, Danhof, 9310, Bloemfontein, Free State, South Africa
4. Department of Environmental Sciences, College of Agriculture and Environmental Sciences, University of South Africa (UNISA), Florida 1709, South Africa