There are actually a large number of species of plants native to the Himalayas, each climactic zone representing its own variations of flora and fauna. This vast mountain range includes tropical, subtropical, temperate, and alpine forests. Estimates of the number of types of plants found in the Himalayas go as high as 10,000. [Conservation International claims there are 10,000 species of plants in the Himalayas] At the lowest levels of the mountains are the forests composed primarily of pine and fir trees, along with rhododendrons and bamboo. As one ascends the peaks, there are dramatic climatic changes, which has a direct influence on the species of plants that grow there. From the bushes that predominate in what is called the “second climatic zone” to the increasingly sparse forestation and relatively more expanses of grass and examples of lichen and mosses. At the highest elevations, the temperatures are too cold, and the ice too prevalent, to support the growth of vegetation.
If one is studying the vegetation of the Himalayas, then, focus has to remain, logically, on the lower levels, mainly the first and second climatic zones. Because the Himalayas had to start somewhere, if one begins at the lowest levels of elevation, there is actually considerable diversity to be found, starting with the tropical rainforests in the eastern part of the mountain range. As one ascends, tropical deciduous forests give way to temperate forests, which lead into the scrublands and, ultimately, to the ice. Because the Himalayas cover such a huge expanse of land, spanning over 420,000 square miles, and reaching a peak elevation at Mount Everest of 29,000 feet, the potential exists for broad variations of vegetation, and that historically has been the case. Human activities have contributed to deforestation and the destruction of some native species of plants, but it remains a diverse region.