Explanation:

Biosphere reserves are areas of terrestrial and coastal ecosystems which promote the conservation of biodiversity with its sustainable use. They are internationally recognized within the framework of UNESCO’s Man and Biosphere (MAB) programme and nominated by national governments.
There are primary and secondary criteria to select a biosphere reserve as follows:
Primary Criteria:
• A site that must contain an effectively protected and minimally disturbed core area of value of nature conservation and should include additional land and water suitable for research and demonstration of sustainable methods of research and management.
• The core area should be typical of a bio-geographical unit and large enough to sustain viable populations representing all trophic levels in the ecosystem.

Secondary Criteria
• Areas having rare and endangered species
• Areas having diversity of soil and micro-climatic conditions and indigenous varieties of biota.
• Areas potential for preservation of traditional tribal or rural modes of living for harmonious use of environment.