Tropical region has richer biodiversity in comparison to others because warm temperature and high humidity of tropical region is favourable for most of the species on earth and tropical areas have more stable climate than temperate regions. In tropical areas, there is greater pressure from pests, parasites and disease. This does not allow a single species topredominate. Species diversity decreases as we move away fromthe equator towards the poles.Tropics harbour more species than temperate or polar areas.