Life on this earth has constantly evolved for last four billion years to form the present spectacular richness of living world. Biodiversity plays a vital role in the material well being of man. Widespread loss of biodiversity has put man's existence at stake. Biodiversity loss is a natural evolutionary process; having been accelerated on account of anthropogenic stresses, habitat loss, invasion of aliens, pests and pathogens, etc. All these events are more or less associated with the human interference to the nature.