The Nilgiri Biosphere Reserve is one of the most popular biosphere reserves in India. It was established in the year 1986, as the first biosphere reserve in India. The reserve is situated in the Western Ghats, in the Nilgiri Hills range of South India and is considered as an International Biosphere Reserve. It was declared under the Man and Biosphere Programme (MAB) of UNESCO and is also under consideration by the UNESCO World Heritage Committee for selection as a World Heritage Site. It encompasses a huge area of 5,520 sq. km. spread in the states of Tamil Nadu, Karnataka and Kerala. The Biosphere Reserve is a wonderful stream amidst greenery in the Nilgiri Hills. The primary objectives behind establishing the reserve include conservation of the in-situ genetic diversity of species, restoration of degraded ecosystems to their natural conditions, providing data for ecological and environmental research and education and functioning as an alternative model for sustainable development.

The Nilgiri Biosphere Reserve is home to several indigenous communities including 10 diverse ethnic groups. The only surviving hunter-gatherers of the Indian sub-continent, the Cholanaickens reside here in the New Amarambalam region of Nilgiris. The reserve also houses a number of protected areas like the Mudumalai WL Sanctuary and National Park, the Wayanad Wildlife Sanctuary, the Bandipur National Park, the Nagarhole National Park, the Nugu WLS, the Mukurthi National Park and the Silent Valley National Park. Apart from that, the Nilgiri Bio-sphere Reserve also includes a few zones of The Nilgiris that are open to forestry and tourism. These zones include the Nilgiris District, the Nilgiris District South, the Erode District and the Coimbatore District in Tamil Nadu. The Nilgiris district in Tamil Nadu is a central focal point and is termed as the manipulation zone in the overall bio-region.

The area of the Nilgiri Biosphere Reserve extends from the tropical moist forests of the windward western slopes of the Western Ghats to the tropical dry forests on the leeward east slopes. The annual rainfall in this reserve ranges from 500 mm to 7000 mm per year and its temperature ranges from 0°C during winter to 41°C during summer. The Nilgiri Biosphere Reserve comes under the bio-geographic region of the Malabar rain forest. It also encompasses three ecoregions, like the South Western Ghats moist deciduous forests, the South Western Ghats montane rain forests, and the South Deccan Plateau dry deciduous forests. The main habitat types found in this reserve include montane rain forest, semi-evergreen moist forest, thorn forest and scrub, montane grassland, and high-elevation Shola forests, etc.

The Nilgiri Biosphere Reserve is home to a large number of flora and fauna species including over 100 species of mammals, 350 species of birds, 80 species of reptiles; about 39 species of fish, 31 amphibians, 60 species of reptiles, 316 species of butterflies and innumerable invertebrates. Some of the rare animals like the Tiger, Asian Elephant, and Nilgiri Tahr are also found in this reserve. The flora of the reserve comprise of 3300 species of flowering plants. Among these, about 1232 are endemic. The genus Baeolepis is exclusively endemic to the Nilgiri Biosphere Reserve. Some of the other notable plants that are entirely restricted to the NBR Reserve include the species of Adenoon, Calacanthus, Baeolepis, Frerea, Jarodina, Wagotea and Poeciloneuron. Apart from them, a total of 175 species of orchids are also found in this reserve. Out of these, 8 species are endemic including the endangered species like Vanda, Liparis, Bulbophyllum, Spiranthes and Thrixspermum.