Of the sixteen hotspot zones in the world, two of them fall in India – the Western Ghats and the Eastern Himalayas. Kalimpong is a precious part of the Eastern Himalayas and boasts a rich bio-diversity. The Neora Valley National Park (88 sq. km), on the north-eastern face of the district with its dense subtropical and impenetrable temperate forest, is a national asset.

There are six natural subtropical forests beginning at different zones:

Mongpong (from Tiger Bridge), continuing to Lish, Guling and Nazoke
Chunabhatti, stretching to Nimbong.
Pubung-Mangzing stretching to Gitdabling,
Dalimkot-Gourbathan, extending to Samsing and above
Kumai, taking its route to Rongo and above and
Jholung Paren to Todey, via Godak.

The Tarkhola and the forests along the eastern flank of river Teesta are connected to Neora Valley through Munsong, Damsang-Algarah and Paktham-Lahba. The second connectivity of forests begin at Chunabhatti (Bagrakote)-Pubung and continues through Nimbong, Pemling, Lolaygaon and Lahba to join Neora Valley. The forests of Ambiok-Dalimkot (Gourbathan), Samsing, Kumai, Rongo, Paaren- Godak and Todey Tangta skirt the national park on the south-eastern flank.

At the foot of Kalimpong, along the river banks of Relli and Teesta, the rain forests can be observed containing the species Acacia (Khair), Meliosma Pinnata (Dabdabe), Albizia (Siris) and Dalbergia (sissoo). The lofty sal trees and the intermixed species of Terminalia, Largerstroemia parviflora, and Dillenia from the sal forest lie in the lower hills. The tropical mixed forests in this zone show the presence of Tetrameles (Maina), Beilschmiedia (Tarsing), Macarange (Malata), along with the undergrowths. The subtropical forests, mostly deciduous, extending to an altitude of 1800m, are home to species like Gynocardia odrata (Gante), Callicarpa (Guenlo), Duabanga (Lampate), Terminalia (Saj), Phyllanthus (Amala), Cinamomum (Tejpat), Engelhardia (Mauwa) and Ficus (Khaniun). The beauty of these forests has been enhanced by the magnificent and lofty climbers like Entada (Pangra), Tinospora (Gurjo, Combretum (Thakauli), Mucuna (Kaoso & Baldengra), Cissus (Charchare).

The popular bio-diversity and typical Himalayan flora is exhibited by the evergreen temperate forests. The temperate ranges cover the forests of Algarah, Charkhola- Lolaygaon, Damsang, Thosum, Todey Tangta and continue above to the Rachela peak, the tri-junction of Sikkim, Bhutan and Kalimpong. Floristically, this climatic border is marked by the presence of certain species like Leucoceptrum canum (Ghurpis), Edgeworthia gardneri (Argeli), Rapidophora (Kanchirno), Thunbergia, Agapetes, etc. There are about seven species of Rhododendrons in the Neora Valley, some of them forming a pure (monoculture) forest at the peak of Rachela. Species like Rhododendron arboreum, Magnolia campbellii, Alcimandra cathcartii, Abutilon indicum, Mussaenda treutlerii and others can be seen along the ridges of Labha, Gumbadara, Jhandi, Damsang, Todey Tangta and above and they are popular with explorers.

The evergreen patches of Pinus, Thuja and Cryptomeria can be seen along the roadsides of Labha and Kafer. The common trees of this temperate forests are Quercus lamellose (Oak), Betula alnoides (Birch), Acer spp. (Maple), Alnus napalensis (Alder), Lyonia, Castanopsis, Lithocarpus, Sorbus, Llex, etc. The upper ridges of this zone are often dominated by the thickets of Arundinaria maling and allied spp. Neora Valley is host to a number of plants of tremendous botanical value. The highly endangered saprophytic herbs of the humus soil of the deep forest, Balanophora and Monotropa are available in this forest. The notable names of vegetational wealth include Rhododendron spp, Tsuga dumosa, Taxus buccata, Helwingia himalaica, Paris Polyphylla, Polygonatum spp, Arasaema spp, Smilax spp, etc., and they form the integral part of this upper forest.

About 300 species of orchids have been reported in this part of the Himalayas. Some of the popular orchids available here are Paphiopedilium, Pleone, Orchis, Herminium, Oberonia, Liparis, Coelogyne, Dendrobium, Cymbidium, etc. along with the common ground orchids like Habenaria, Satyrium, etc. The only medicinal plant garden of the nation that cultivates the precious Cinchona (and has its headquarters at Mungpoo) has a major stretch of cultivation in Kalimpong – at Munsong and Rongo – Gairibas. The commercial cultivation of Cinchona spp, Dioscorea spp, Cephaelis ipecacuanha, and other herbal plants such as Digitalis, Solanum, Rauwolfia, Mentha etc. have ben carried here since its inception in the 60s.

The faunal diversity of this region is another interesting asset. There is record of about 130 mammals, 550 birds, 125 freshwater fish, 51 reptiles, 25 amphibians, 43 moths and 24 butterflies in the district of Darjeeling. The wildlife of Kalimpong is enriched by the presence of endangered species like the red panda and munal pheasant, Himalayan black bear, clouded leopard tiger, Himalayan tahr, goral, gaur and pangolin at widely different altitudes. The forest belts host the Siberian weasel, today cat, Asiatic black bear, common India leopard, barking bear, Indian bison, moupan hare and Himalayan squirrels.

Some of the many birds found here are sparrow hawks, Indian besra, griffon vulture, kaleej pheasant, a variety of hornbills, woodpeckers, owls, Indian black-crested baza, etc. The Neora Valley is birdwatching heaven. The dominant genera in the amphibian species are Rana, Loepa and butterflies like Pieris, Poutia, Apollo, Papilio etc. can be spotted. A good number of studies have been conducted on the flora and fauna of this region, yet a lot is left for the naturalists and nature enthusiasts to explore.