The Nilgiri Biosphere Reserve is an International Biosphere Reserve in the Western Ghats, Nilgiri Hills range of South India. The Western Ghats, Nilgiri Sub-Cluster (6,000+ km²), conjoining the Nilgiri Biosphere Reserve, is under consideration by the UNESCO World Heritage Committee for selection as a World Heritage Site. This biosphere consists of a large number of well protected National Parks, Sanctuaries and Tiger Reserves.
The Mudumalai WL Sanctuary and National Park (321.1 km²), Wayanad Wildlife Sanctuary( 344km²), Bandipur National Park(874km²), Nagarhole National Park (643 km²), Nugu WLS, Mukurthi National Park (78 km²) and Silent Valley National Park (89.52km²) are protected areas within this reserve. The Bio-sphere Reserve also includes zones of The Nilgiris open to forestry and tourism including: Nilgiris District (North (448.3 km²) and Nilgiris District South (198.8 km²)), Erode District (Sathyamangalam forest (745.9km²) and Erode(49.3 km²)) and Coimbatore District (696.2 km²) in Tamil Nadu.
The reserve extends from the tropical moist forests of the windward western slopes of the Ghats to the tropical dry forests on the leeward east slopes. Rainfall ranges from 500 mm to 7000 mm per year. The reserve encompasses three ecoregions, the South Western Ghats moist deciduous forests, South Western Ghats montane rain forests, and South Deccan Plateau dry deciduous forests. The habitat types include montane rain forest, semi-evergreen moist forest, thorn forest and scrub, montane grassland, and high-elevation Shola forests.
(Sholas are typical to the Western Ghats - a type of high-altitude stunted evergreen forest . Patches of shola forest are usually separated from one another by undulating grassland. Together the shola and grassland form the shola-grassland complex or shola-grassland mosaic. Shola forests are found only in the southern portion of the Western Ghats mountains of Karnataka, Kerala and Tamil Nadu states, in the South Western Ghats montane rain forests ecoregion. Due to its altitude and evergreen character, it is home to some of the most threatened and endemic species. Some of the species found here have close relatives only in the distant evergreen forests of northeast India or those in Southeast Asia. Some others are found nowhere else in the world.)