Diversity and Ecology of Odonates in Coimbatore District

Abstract

The global biological diversity is to be treated as a wealth considering its potential role in ecosystem sustenance and management. The declining status and vulnerability of biological diversity to various human-induced problems, compels us to index and preserve species and their habitats as a continuous and crucial process. Exploding human population, degrading environment and loss of habitats are three major reasons for the irreversible loss of biological diversity especially in the tropics (Wilson, 1988). To understand the causes behind the ecological and evolutionary processes responsible for the rich biodiversity and also the ecosystem service biodiversity provides, it is very essential to know how many species inhabit this earth (May, 2011). There are presently 1.9 million catalogued species in the world of which nearly one million are insects (Chapman, 2009), while the estimated number of global species by taxonomists is between three and 100 million species (May, 2010). This estimation of biodiversity based on taxonomic patterns varies from the estimates based on macroecolgical patterns and diversity ratios. Erwin (1982) estimated 30 million species of Arthropods, based on the host specificity of guilds in beetle samples and subsequent hierarchical ratio extrapolations.