what is the importance of biosphere reserves, wildlife sanctuaries and national parks?

The main functions of biosphere reserves are:

1) To conserve landscapes, ecosystem and various species.
2) Leads to development of the human and economic development to make them culturally, economically and socially culturable.
3) It provides support for the research, monitoring, education and information exchange for the topics related to local, national and global issues of conservation and development.

The main functions of wildlife sanctuaries and national parks is to conserve and provide a home-like environment to various endangered species of animals and birds of the country.