The Himalaya: an overview

The Himalaya are 2250 km long and stretch from the Nanga Parbat range and the Karakorams where the great Indus is born. From here, the great chain traces a south-easterly direction through Kashmir, Himachal and Uttar Pradesh in India and into the Nepal Himalaya which is about 700 km long and on an average 140 km in breadth. Moving through Nepal, the chain of the Himalaya leads into the Indian state of Sikkim and the northern portion of West Bengal, with the Bhutan Himalaya being a close neighbour. From here, the Himalaya traces itself through the northern portions of Assam and right across Arunachal Pradesh at the north-eastern most portion of India, where the Brahmaputra river, or the Tsang-Po enters India.

Environmental factors governing floral diversity and composition

The Himalaya harbour one of the richest ranges of floral and faunal diversity
in the world. Although no formal figure for the total number of seed-plants exists, the Western Himalaya could well harbour upwards of 7500 species, and even this could be an understatement. There are a number of exotic species that have made their way to the Himalaya and established themselves here, at places even outcompeting indigenous species. There are several plants that would essentially be classed as belonging to the plains but which have been consistently increasing their ranges to include areas of increasing altitude in the foothills of the Himalaya.

When talking of the Himalaya, we must also give consideration to the several subsidiary ranges that lie between the 'Himalaya-proper' and the plains. For example, when traveling to the foot-hill town of Mussoorie, through the town of Dehra Dun, we are not really traversing Himalayan foothills, but crossing the range of the Shiwaliks, which stretch westwards into Himachal Pradesh and eastwards through the Rajaji and Corbett National Parks. We must also consider the Terai region which stretches along with the Himalayan foothills all the way east through Nepal and is replaced by the Bhabar in the far east. Here the vegetation is vastly different from the Himalaya, as the forests are dense and tropical in nature, and there is a lot of moisture.

Previous Next