The Indian Central Himalaya Region (ICHR), spreading over a geographical area of 53,485 km2, supports a population of 8,479,562 who constitute about 0.83 and 21.40% of the total population of the Indian Republic and Indian Himalayan Region (IHR) respectively. The region is synonymous with the newly constituted Himalayan state of Uttaranchal. The geographical area of the region is dispersed within an altitudinal variation ranging from 200 m to more than 8000 m amsl. It is composed of five litho-tectonically and physio-graphically distinct subdivisions, namely the Outer Himalaya comprising the Tarai and Bhabhar, the Sub-Himalayan belt of the Siwalik, the Lesser Himalaya; the Great Himalaya and the Trans-Himalaya or Tethys. The climate and consequently the biological communities vary considerably along the gradients of this mountain ecosystem, giving a heterogeneous dispersion of biodiversity elements in the region2. Conservative estimates indicate that the region harbours more than 700 species of medicinal plants out of the 1748 and 2500 species reported in the IHR and India respectively3. It also supports remarkable cultural and ethnic diversity, and human habitation is found up to an altitude of 3500 m asl.
