High forest covers about 170,000 km2 in the south of Nigeria, stretching from the border with the Republic of Benin to the Cameroun mountains.
It comprises of dry lowland rain forest zone with fresh-water swamps in the south and the zone of derived savanna in the north up to latitude 8° N, (Sutter, 1979). The original high forest vegetation has been considerably modified by human activities including burning, grazing, clearing, slashing and tillage for farming resulting in oil palm bush, forest-savanna mosaic, tree crop plantations, derived savanna and to a limited extent more grassy savanna, within the rainforest zone.
Agricultural activities of southern Nigeria are related to the prevailing climatic conditions of high rainfall, constantly high temperatures, high atmospheric humidities, and precipitation usually exceeding evapotranspiration for more than half the year.
The agricultural products are also related to the vegetation types.
The farming systems in the forest zone, in general, involve the following enterprises (Okigbo, 1981):