**2.1.1 Geographical extent**

The Eastern Ghats are a discontinuous range of mountains along eastern coast of Peninsular India extending over 1750 km with the average width of about 100 km and extends from 10005' to 22030' N Latitude and 76023' to 86050' E longitude (Fig. 2). The Eastern Ghats are ΄tors΄ of geological antiquity and are geologically older than Himalayas and Western Ghats. Eastern Ghats cover four states (Orissa, Andhra Pradesh, Tamil Nadu and small portion of Karnataka) and present study was undertaken in the Eastern Ghats part of Andhra Pradesh lying approximately between 12 – 19 N latitude and 76 – 84 E longitudes. It is bounded by Eastern coast on the East, Deccan plateau on the West, South and North covers the Eastern Ghats part of Tamil Nadu and Orissa state respectively.

Study area includes Eastern Ghats districts of Andhra Pradesh viz., parts of Srikakulam, Vizianagaram, Visakhapatnam, East Godavari, West Godavari, Khammam, Krishna, Mehbubnagar, Nalgonda, Guntur, Kurnool, Anantapur, Prakasam, Kadapa, Nellore and Chittoor (Fig. 2). The total geographical area covered under Eastern Ghats of Andhra Pradesh is 98,662 km2 having 23,894 km2 of forest area. Major rivers like Godavari, Krishna and Pennar cut the range into discontinuous blocks of hills along the East coast in Andhra Pradesh. Major forest range includes the Upper Sileru range in north, lower Velikonda Range lies to the east, and the higher Palikonda-Lankamalla-Nallamalla ranges in the west.

Eastern Ghats also harbours wide range of wild crops (millet, rice) and economic and medicinal plants. Endemic plants of this region are basically Palaeo-endemics and are localized. They have very narrow distribution range and several studies indicate that they are under gradual process of extinction (Reddy et al., 2006). Nearly, 54 tribal communities inhabit Eastern Ghats region (MoEF, 1997). The Eastern Ghats also harbours one of the richest Bauxite deposits in the world.
