Nilgiri and Agasthyamalai are the two biosphere reserves of Kerala

Background

The Kerala Forest Department lists two Biosphere Reserves in the state: Nilgiri and Agasthyamalai.
Nilgiri, also the first BR of India, extends into Karnataka, while Agasthyamalai stretches into Tamil Nadu.
The extent of the Nilgiri Biosphere Reserve is given as 1455.40 Sq. Km, and the Kerala part includes Wayanad Wildlife Sanctuary, Silent valley National Park and the Nilambur, Mannarkkad, Palakkad and Kozhikode forest areas.
The extent given for Agasthyamalai is 1828 Sq. Km, covering Neyyar, Peppara and Shendurney wildlife sanctuaries along with the Achencoil, Thenmala, Konni, Punalur and Thiruvananthapuram divisions and the Agasthyavanam Biological Park Range.
The Biosphere Reserve concept was introduced by UNESCO under its Man and Biosphere Programme (MAB) during 1971.
A Biosphere Reserve is a voluntary, co-operative conservation area meant to protect biological and cultural diversity while promoting sustainable economic development.
Because they are relatively larger areas, biosphere reserves stand for landscape level conservation, beyond even state or nation borders.