The effects of tropical forest structure and species composition on species diversity were studied using the data of 279 biodiversity inventory plots, in the forest reserves of the East Usambara Mountains (EUM) in the northeastern part of Tanzania, among the 25 global “hot spots” for biodiversity conservation. A standard method of vegetation plot sampling was used, based on a 450 m grid system constructed throughout the forest on transect lines. A plot of Full-size image (