I am a professor of Geography at the University of Ibadan. My research interests include soils, vegetation ecology and biogeography. I have been studying shifting cultivation, with special emphasis on soil and vegetation dynamics during the fallow period, trees in traditional agro-forestry systems and their role in soil conservation for a couple of decades. I have also devoted considerable attention to quantitatively characterizing soil changes under monocultural plantations of teak, gmelina, rubber, oil palm and cashew.