Ecology of the Himalayas

The climate ranges from tropical at the base of the mountains to permanent ice and snow at the highest elevations.

This diversity of climate, altitude, rainfall and soil conditions supports a variety of distinct plant and animal species, such as the Nepal gray langur (Semnopithecus schistaceus)[1] On the Indo-Gangetic plain at the base of the mountains, an alluvial plain drained by the Indus and Ganges-Brahmaputra river systems, vegetation varies from west to east with rainfall.

The xeric Northwestern thorn scrub forests occupy the plains of Pakistani and the Indian Punjab.

[5] Above the alluvial plain lies the Terai strip, a seasonally marshy zone of sand and clay soils.

Permeable conglomerates and other rocks allow rainwater to percolate downslope into the Bhabhar and Terai, supporting only scrubby forests upslope.

At these elevations and above, the biogeography of the Himalayas is generally divided by the Kali Gandaki Gorge in central Nepal, one of the deepest canyons in the world.

North of the Main Central Thrust, the highest ranges rise abruptly as much as 4,000 meters (13,000 ft) into the realm of perpetual snow and ice.

As the Himalayan system becomes wider from east to west, the number of parallel high ranges increases.

For example, the Kagmara and Kanjiroba ranges both reach well over 6,000 meters (20,000 ft) north of the Dhaulagiri Himalaya in central Nepal.

The areas above natural treeline is chiefly composed of annuals, which is differentiated into alpine grasslands and meadows.

[12] The northwestern Himalayan alpine shrub and meadows are found in the high elevations of northern Pakistan, Jammu and Kashmir, and Himachal Pradesh.