State the functions served by biosphere reserves

State the functions served by biosphere reserves.

Bio-reserves achieve three interconnected functions, i.e. conservation, development and logistic support.
To fulfil these functions, they contain three interconnected zones.
(i) Core zone It is a securely protected site for conserving biological diversity, monitoring minimally disturbed ecosystems and undertaking non-destructive research and other low-impact uses like education.
(ii) Buffer zone It surrounds or adjoins the core area and is used for cooperative activities compatible with sound ecological practices, including environmental education, recreation, ecotourism and applied and basic research.
(iii) Transition/development zone It may contain a diversity of agricultural activities, settlements and other uses and in which local communities, management agencies, scientists, NGOs, cultural groups, economic interests and other stakeholders work together to manage and sustainably develop the area’s resources. Thus, properly managed biosphere reserves are important for preserving biological diversity.