Implications of land use change for the production of plant biomass in densely populated Sahelo-Sudanian shrub-grasslands in north-east Nigeria.

The production of plant biomass on small farms and in woodland in densely populated locations in the Nigerian Sahelo-Sudan is estimated in order to test the hypothesis that conversion of land from natural vegetation to cultivation entails a loss in plant productivity. Estimates are given for reserved forest, woodland, shrubland and farmland at two sites varying in mean annual rainfall and population density. The results fail to support the hypothesis. The role of farmers in causing degradation through loss of plant productivity, and appropriate conservation strategies, may require re-evaluation.