Sikkim due to its altitude variation right from 800 feet to the summit of Mount Khangchendzonga the third highest peak in the world, where with its infinite variety of its geographic settings, its topography, the flora and fauna is unique in its diversity, where remarkably such a small area comprise of nearly all the species and varieties covering the area from tropical to alpines. Sikkimese botanical and zoological richness can be described as the fabulous treasure house of faunal, floral and avian diversity. Dr J. Hooker in the mid 20th Century A.D. had detailed the botanical wealth and richness of Sikkim and more recently Dr. Salim Ali, the celebrated ornithologist of India had given the detailed account of birds in his book “The birds of Sikkim”.
Plants
Alpine regions ranging above 10,000 feet with the snow covered forests are the Rhododendrons, Juniper, Cypresses and Pines. The lowlands at South with more tropical climate have vegetation such as Figs, Laurels, Sal, Teak, Oak and Bamboos. The terraced farmlands have Rice, Maize and Barley as the main crops. The temperature forest contains Chestnut, Maple, Birch, Magnolia and Silver Fir. Other crops like Ginger, Potatoes, Oranges, Passion Fruit, Guava, Maize etc., are grown in temperate and tropical regions. Moreover, as a whole, Sikkim has more than 450 species of Orchids, 4000 species of plants and more than 36 species of Rhododendrons growing in temperate and alpine zones.
Animals
Sikkim it is said has more than 500 species of avi-fauna from the majestic Bearded Vulture with wing–span of over 10 feet to the Olive Ground Warbler which is just a few inches in length. Amongst others are the Emerald Dove, Woodpeckers, Cuckoos, Kingfisher, Vultures, Giant Lammergeier, Eagles, Whistling, Thrush, Minivets, Bulbuls, and Pheasants etc. It is said that some migratory birds also frequent the land of Sikkim. Sikkim also has more than 600 species of Butterflies which many of them rare and endangered. The forest share habitat with Barking Deer, Red Panda, Musk Deer, Leopard Cats, Flying Squirrels etc. Higher up in north Blue Sheep, Shapi, Tibetan Wild Ass, Himalayan Black Bear, Snow Leopard etc., roam the ground freely.