Abstract
Inventorying, understanding the level, distribution and dynamics of biodiversity have considerable significance in long-term health and vigour of the biosphere. The diversity indices commonly used are based on the assumption that biological diversity can be satisfactorily described by two major components viz: the number of species and their relative abundance. In order to understand the complexities and 'niche' characteristics of community, or a landscape, or a geographic area the ecological level of diversity has considerable significance. The ecosystem and ecological levels of diversity of tree species of Peppara Wildlife Sanctuary was assessed following Whittaker (1977) . Tah samplings were done by stratified sampling method using quadrats. A total of 151 tree soecies spread over 52 families were recorded out of nine forest types