Forty to fifty million years ago, the Indian and Eurasian tectonic plates collided, initiating the ascent of the mountains known today as the Himalayas. The merging of these two continental landmasses created a landscape that now contains the world’s highest mountains. Abrupt rises in elevation and geological complexity have generated a diversity of ecological conditions, and the Himalayan region consists of a variety of ecoregions as recognized by the WWF. The collision of these tectonic plates brought together flora and fauna from two distinct regions, boosting biodiversity. There are an estimated 10,000 species of plants, 1,000 species of birds, and 300 species of mammals that thrive in the Himalayas, and a substantial proportion of those species are endemic to their ecoregion.
Monsoon rains originating from the Bay of Bengal to the east release their moisture on the southern and eastern side of the Himalayas, causing the southeastern ecoregions to be wetter than their western counterparts. Tropical moist forests of India border the Himalayas to the south, which give way to low elevation subtropical grasslands of India, Bhutan, and Nepal. To the west of the Himalayan region, dry thorn scrub forests and arid shrublands spread extensively throughout eastern Pakistan and western India. Temperate broadleaf forests are found in middle elevations, transitioning to higher elevation coniferous forests. Alpine shrublands and meadows are found above treeline and occupy the highest livable plant zone.
Be sure to visit our pages on the ecoregions and ecology of the Himalayas (linked below) for more detailed information about this unique region.
Hanks, B. (2015). The Himalayas: Two continents collide. Retrieved April 4, 2016, from http://pubs.usgs.gov/gip/dynamic/himalaya.html
Wikramanayake, E. D., Dinerstein, E., & Loucks, C. J. (2002). Terrestrial Ecoregions of the Indo-Pacific: A Conservation Assessment. Island Press.