Measurement of tree diversity in the Nigerian rainforest

Results are presented from a study that examined, in terms of species richness and heterogeneity, the diversity of trees in the Nigerian rainforest at the beta and gamma levels, which are between-site and landscape levels, respectively. Five sites were selected within the rainforest, representing major climatic, geological, and edaphic variations. Measurement of species diversity, measurement of similarity between sites, and ordination analysis were used to explore the extent of diversity. Results indicated a clear variation in the species composition in different parts of the rainforest area, with a gradient of floristic richness from the western to the eastern parts of the forest zone, attributed to climatic/geological and management factors. Species-richness differences are discussed in terms of nutrient deficiencies, rainfall, and soil types.