The Western Ghats run in a north-south direction over 1600 km
parallel to the west coast of peninsular India. The Anamalai hill
ranges (comprising Anamalai, Nelliyampathy and Palani hills) are
situated in the southern Western Ghats (76.38◦ E and 10.44◦ N to
77.55◦ E and 10.34◦ N) to the south of the Palghat Gap, extending
over an area of c. 5700 km2. The landscape is characterized by
its wide altitudinal gradient ranging from c. 100 m above MSL on
either side of the Ghats to 2694 m at Anaimudi Peak, the highest
point south of the Himalaya. The sharp altitudinal gradient results
in significant variation in the amount of precipitation across the
landscape, with the western face and crest-line of the hills enjoying
higher rainfall (mean annual rainfall up to 3500 mm), and the
eastern rain shadow region receiving lower annual rainfall (mean
rainfall about 800 mm). The rainfall gradient from east to west,
along with the complex topography, results in heterogeneous vegetation
types: from lowland tropical dry thorn forest mostly on
the eastern side, mid-elevation tropical dry and moist deciduous
forests, high elevation tropical semi-evergreen and evergreen
forests to stunted montane forests (locally known as sholas) and
grasslands