Northeast India is very rich in biodiversity and it is recognized as one of the 17 hotspots of the world. The region is the meeting place of at least three main streams of flora and fauna, namely the Indian mainland stream from the west, the China-Japanese stream from north and northeast, and the Malaya stream from south and southeast. The species have induced naturally hybridization effecting the production of high species variability.
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Biodiversity of Northeast Indian States
Northeast India comprises 51 types of forest ranging from tropical rainforest to alpine vegetation. There are 95 plant genera that are endemic to Northeast India. The development and spread of flowering plants in the region are immense with ten dominant plant families representing by, 3,000 species. There are 7,000 flowering plants, 6,000 pteridophytes and about 650 orchid species are found in this region.
Northeast India is very rich in faunal diversity. There are as many as 15 species of non-human primates and most important of them are hoolock gibbon, stumptied macafue, pigtailed macague, golden langure, hanuman langur and rhesus monkey.
The most important and endangered species is one-horned rhinoceros. The forests of the region are also the habitats of elephant, royal Bengal tiger, leopard golden cat, fishing cat, marbled cat, etc. the Gangetic dolphin in the Brahmaputra is also one the endangered species. The other endangered species are otter, crocodile, tortoise and some fishes.
Northeast India region consists of eight states viz- Assam, Arunachal Pradesh, Mizoram, Manipur, Nagaland, Tripura, and Sikkim. every state has variation in its flora and fauna which are broadly discussed here.
Biodiversity of Assam
The State of Assam is a constituent unit of the Eastern Himalayan Biodiversity Region; one of the two biodiversities “Hot Spots” in the country. The climatic condition and wide variety in physical features witnessed in Assam have resulted in a diversity of ecological habitats such as forests, grasslands, wetlands, which harbor and sustain wide-ranging floral and faunal species placing. Forest of Assam has a rich biodiversity of flora and fauna. It has a wide range of forest viz-
1. Tropical Wet Evergreen Forests
Golaghat, Jorhat, Sibsagar, Tinsukia, Dibrugarh and in a narrow stretch in Lakhimpur and Dhemaji districts along foot hills. Hollong (Dipterocarpus macrocarpus), the tallest tree of Assam and also the “State Tree” is the most predominant constituent of these forests. The associated species are Borpat, Jutuli ,Sam, Dewa sam, Nahar , Teeta chap, Bhelu, Mekai etc.
2. Tropical Semi Evergreen Forests
3. Tropical Moist Deciduous Forests
4. Sub-tropical Broadleaf Hill Forests
5. Sub-tropical Pine Forests
6. Littoral and Swamp Forests
7. Grassland and Savannahs
Assam’s mammalian diversity is represented by 193 species which are widely distributed in this region. But of late some of the species like one-horned rhinoceros, water buffalo, pigmy hog, swamp deer, golden langur, hoolock gibbon have their distribution limited to isolated pockets and protected areas.
Assam forms the westernmost boundary for the Indo-Chinese species including primates and the easternmost limit of several peninsular mammalian fauna.
The distributional extent of several Indian species including clawless otter, the spotted deer, the swamp deer, the stone marlin, the hispid hare, the great Indian one-horned rhinoceros, the pigmy hog, etc. have terminated in Assam plains.
The distributional range of several Indo-Chinese fauna gets its sustenance from this region. Mention can be made of its sustenance from this region.
Mention can be made of such species like clouded leopard, the marbled cat, the golden cat, the spotted linsang, the large Indian civet, the binturong, the crab-eating mongoose, the ferret badger, the hog badger, the hoary bamboo rat, the bay bamboo rat, etc. Assam is home to all the primate species found in the North-Eastern region.
In Assam, as many as 293 species of Orchids are reported which represent 44.39% of North East species and 24.42% of species occurring in India. Orchids as a group of flowering plants exhibit a wide range of habits and have specific macro climatic requirements for their growth, development and regeneration.
Assam orchids show all the habits and growth forms found in
Orchidaceous taxa. Mostly they are epiphytes. Goodyera procera and Spiranthis
sinesis are adapted to aquatic habitats whereas Vanilla pilifera and Galeola
altissima are climbers.
Biodiversity of Arunachal Pradesh
This diversity of topographical and climatic conditions has
favored the growth of luxuriant forests which
are home to myriad plant and animal forms adding beauty to the
landscape. Living in this incredible cradle of nature are the colorful and
vibrant tribes of Arunachal Pradesh for whom the forests and the wildlife are
of special significance.
Arunachal Pradesh in the Eastern Himalayas of India is among the 200 globally important ecoregions. It is also considered as one of the eighteen “biodiversity hotspots” in the world. An estimation that over 5000 species of flowering plants are found (of both vascular and non-vascular origin) here, out of which, 238 are endemic to the state.
The state is rich in agro-biodiversity and has been a center of origin for a number of crop plant species. Orchids are often associated as the “Jewels of Arunachal Pradesh”, more than 500 of its varieties can be found here.
The state has more than 500
species of fauna and shelters four major cats namely tiger, leopard, clouded
leopard, snow leopard, and also rare lesser feline species like the Golden Cat
and Marbled Cat. It also covers an amazingly rich variety of avifauna with over
650 bird species.
Biodiversity of Meghalaya
Meghalaya is richly endowed with forest resources. According to the State of Forest Report - 2001 published by the Forest Survey of India, the extent of total forest cover in the State is 15,584 sq km which is 69.5 % of the total geographical area of the State.
The following table gives break up of forest cover into dense and open forests which have been defined as forests having canopy density more than 40% and between 10-40% respectively. The scrub forests have a canopy density of less than 10%.
The forests of Meghalaya can be broadly classified into the following types :
1. Alluvial Sal
This type conforms to type North Indian Tropical Moist Deciduous Kamrup Alluvial Sal Forests
2. Foothill and Plateau Sal
This type conforms to the type North India Tropical Moist
Deciduous Eastern Hill Sal Forests. Very Moist Sal Bearing Forests – Khasi
Hills Sal.
3. Mixed Deciduous Forests
North India Tropical Moist Deciduous (East Himalayan Moist
Deciduous Forests.
4. Evergreen Forests
These forests conform to the type Northern Tropical Semi-Evergreen
Forests.
5. Bamboo Forests
This type conforms to the type Northern Tropical Semi-Evergreen
Forests.
6. Grasslands
Northern Tropical Moist Deciduous Forests – Low Alluvial Savannah Woodland.
Meghalaya also has a large variety of mammals, birds, reptiles and insects. The important mammal species include elephants, bear, red pandas, civets, mongooses, weasels, rodents, gaur, wild buffalo, deer, wild boar and a number of primates.
Meghalaya also has a large variety of bats. The
limestone caves in Meghalaya such as the Siju Cave are home to some of the
nation's rarest bat species. The hoolock gibbon is found in all districts of
Meghalaya. Common reptiles in Meghalaya are lizards, crocodiles and tortoises.
Meghalaya also has a number of snakes including the python, copperhead, green
tree racer, Indian cobra, king cobra, coral snake and vipers.
Meghalaya's forests host 660 species of birds, many of which are endemic to Himalayan foothills, Tibet and Southeast Asia. Of the birds found in Meghalaya forests, 34 are on worldwide threatened species list and 9 are on the critically endangered list.
Prominent birds spotted in Meghalaya include those from the families of Phasianidae, Anatidae, Podicipedidae, Ciconiidae, Threskiornithidae, Ardeidae, Pelecanidae, Phalacrocoracidae, Anhingidae, Falconidae, Accipitridae, Otididae, Rallidae, Heliornithidae, Gruidae, Turnicidae, Burhinidae, Charadriidae, Glareolidae, Scolopacidae, Jacanidae, Columbidae, Psittacidae, Cuculidae, Strigidae, Caprimulgidae, Apodidae, Alcedinidae, Bucerotidae, Ramphastidae, Picidae, Campephagidae, Dicruridae, Corvidae, Hirundinidae, Cisticolidae, Pycnonotidae, Sylviidae, Timaliidae, Sittidae, Sturnidae, Turdidae, Nectariniidae and Muscicapidae. Each of these families have many species.
The great Indian hornbill is the largest bird in Meghalaya. Other regional birds found include the grey peacock pheasant, the large Indian parakeet, the common green pigeon and the blue jay. Meghalaya is also home to over 250 species of butterflies, nearly a quarter of all butterfly species found in India.
Biodiversity of Manipur
Manipur blessed with an amazing variety of flora and fauna, 67% of the geographical area of Manipur is hill tract covered forests. Depending on the altitude of hill ranges, the climatic condition varies from tropical to sub-alpine.
The wet forests and the pine forests occur between 900-2700 m above
MSL and they together sustain a host of rare and endemic plant and animal life.
Coveted the world over as some of the most beautiful and precious blooms,
orchids have an aura of exotic, mysteries about them.
In Manipur, they are abound in their natural habitat growing
in soil or on trees and shrubs speaking their beauty and colour, stunning the
eye that is not used to seeing them. in such profusion. There are 500 varieties
of orchids which grow in Manipur of which 472 have been identified
In addition to 'Siroi Lily' which is the only terrestrial lily grew on the hilltops of Siroi hill, Ukhrul, the Hoolock Gibbon, the Sloe Loris, the Clauded Leopard, the Spotted Linshang, Mrs. Hume's Barbacked Pheasant, Blyths Tragopan, Burmese Pea-Fowl, four different species of Hornbills etc. form only a part of the rich natural fauna of Manipur. However, the most unique is the Sangai the dancing deer.
The floating mass of vegetation
on the Loktak Lake sustains small herds of this endemic deer which
unfortunately has the dubious distinction of being the most threatened Cervid
(known as Phumdi) in the World. Other mentionable fauna is Salamander known as
'Lengwa' found at the foothill of Siroi in Ukhrul.
Biodiversity of Mizoram
A total of 2,358 species of plants have been recorded from Mizoram. Out of the total species, 2,141 belong to Angiosperms distributed over 176 families and 905 genera. Out of this, 1641 species belong to dicots and the remaining 500 are monocots.
The number of gymnosperms is quite less i.e. only six species belonging to 6 genera and 4 families, while the number of pteridophytes is quite high i.e. 211 species distributed over 35 families and 66 genera.
Some of the important floral components of the state are mentioned below:
Timber species:
There are about 125 good timber yielding species reported from the state. Some of the common timber species of the state are Albizia lebbeck (Thingri), A. odoratissima (Kangtek), Artocarpus chama (Lamkhuang), Chukrasia tabularis (Zawngtei), Haldinia cordifolia (Lungkhup), Michelia champaca (Ngiau), Morus laevigata (Lungli), Phoebe goalparensis (Lawngthinhtha), Schima wallichii (Khiang), Terminalia myriocarpa (Char) etc.
Orchids:
Orchids are very common and about 251 species have been reported from the state . Some of the most ornamental orchid species found in the state are Coelogyne barbata, Cymbidium elegans, C. mastersii, Dendrobium chrysanthum, D. densiflorum, D. fimbriatum, Eria paniculata, Paphiopedilum villosum, Phaius flavus, Thunia alba, Vanda coendea, Renanthera imschootiana and Rhynchostylis retusa.
Wild Relatives of Cultivated Crop Plants:
There are many wild relatives of the cultivated crops, which
have been preserved since long by the society. Some of the important species
are Artocarpus chama, Citrus indica, C. medica, Camellia caudata, and
species of Alpinia, Ammomum, Cajanus, Cinnamomum, Cissus, Colocasia,
Curcuma, Garcinia, Ipomoea, Musa, Piper, Saccharum, Zingiber etc. These species might be very
useful in evolving the new varieties of desired characters.
Medicinal and ethnobotanical Plants:
The state has rich diversity of medicinal and ethnobotanical plants. Due to the close association of people with nature, their knowledge of useful plants of the region is very good and it is interesting to note that all important and useful species have been assigned a local name and because of their culture and one language, it becomes very easy to locate a plant in an area by simply telling its local name. So far, about 500 species under 383 genera have been recorded from the state, which have medicinal and ethno-botanical uses.
Recently 35 species of bamboos have been reported from the state out of them, 20 species are indigenous to the state, while 14 species have been introduced from outside. Bambusa tulda (Rawthing), Dendrocalamus longispathus (Rawnal),D. hamjltonii (Phulrua), Melocanna baccifera (Mautak), Melocalamus compactiflorus (Sairil), Sinarundinaria griffithiana (Phar) are the main species of the bamboos found in the state. Approximately 80% of the total bamboo area is occupied by Melocanna baccifera.
Fungi:
Mizo people are very fond of eating wild fungi. Maupa
(Cantharellus tropicalis), Pasi (Schizophyllum commune), Pasawntlung (Termitomyces species)
are commonly seen in the market. Recently Bisht (2011) has reported 52
species of wood decaying fungi from the state. This study does not include
mushrooms and other groups of fungi and it is assumed that at least 200 species
of mushrooms can easily be reported from the state.
Fauna:
Mizoram is home to a great variety of wildlife species, which have a significant influence on the tradition and culture of local people. Owing to its strategic location, it has a very rich diversity of faunal species, for example, out of the 15 primates.
Mizoram harbors as many as 8 species. Among these, except rhesus macaque, all species are endemic to the region viz., hoolock gibbon (Hauhuk), pig-tailed macaque (Zawnggrengte), stump-tailed macaque (Zawngmawt), phayre’s leaf monkey (Dawr), capped langur (Ngau) and slow loris (Sahuai). Of the five big cats in India, Mizoram has 3 of them sans Asiatic Lion and Snow leopard.
Out of the 11 smaller cats, the state harbors as many as 5 species, of which Golden Cat and Marbled Cat are endemic to this region and are extremely rare. Malayan Sun Bear, which was thought to be extinct in the wild from the Indian subcontinent is recently recorded and photographed through camera trap at Dampa Tiger Reserve.
The bird diversity is also quite high and 215 species have been reported from Dampa Tiger Reserve alone and possibly much more can be recorded if proper research is strengthened.
Biodiversity of Nagaland
Nagaland lies in the 10th distinct bio-geographic zone under one of the identified 18 Mega hot spot in the world with reference to threats to biodiversity. It has the finest Tropical, Subtropical Evergreen forests and a unique Broad leaved Moist Temperate forests.
The floral vegetation and fauna elements represent
the transition zone of Indian, Indo Malayan and Indo Chinese bio-geographic
region. Many ancient angiosperms & primitive flowering plants are present
and the area is considered as a cradle of flowering plants. It is also the
Center of origin of some rice variety and secondary origin of citrus, chilly
and maize, etc.
The flora of Nagaland shows great affinities with flora of Indo-Malaya and Indo-China. The angiospermic flora is represented by about 2,431 species belonging to 963 genera and 186 families. In this, the share of dicots is 1,688 species, 724 genera from 158 families and monocots by 743 species under 239 genera from 28 families. Gymnosperms also register their presence with 9 species, under 6 genera from 5 families.
There
are over a thousand species of orchids in India and Nagaland alone has about
360 orchid species. There are about 71 bamboo species, 12 cane species and 41 allied
species, 346 lichens and 103 Red Data Plants. The faunal diversity includes
about 67 common wild animals, 519 bird species and 149 fish species and a
number of reptiles and amphibians.
The great Indian hornbill is one of the most famous birds found in the State. Blyth’s tragopan, a vulnerable species of pheasant, is the State bird of Nagaland. It is sighted on Mount Japfü and Dzükou valley of Kohima district, Satoi range in Zunheboto district and Pfütsero in Phek district.
The world’s biggest and tallest Rhododendron tree discovered in 1993 featured in the Guinness Book of World Records, measuring up to 108 feet and can be found at the base of Japfü Peak. Mithun, an endemic animal to North-East India is the State animal of Nagaland.
The state is also known as “Falcon Capital of the World.” It is the primary stopover roosting site for Amur falcons in places like Wokha, Longleng, Peren, Dimapur, Phek etc.
The famed Guinness World Records, London recognized the
Melhite Lha (paddy) species as the tallest Paddy in the world on December 2001
and Naga King Chilly was also recorded as the World’s Hottest Chilly in 2007.
FLORA
Dipterocarpousmacrocarpous (Hollong), Shoreaassamica (Makai) ,Rodhodendron Spp. , Mesuaferra (Nahar), are rare and endangered spp. Panaxgensing (Gensing) is found only in Tuensang district at higher altitude.
It is endangered. Aquilariaagallocha (Agar)is also an endangered species. Rare and Endangered species of Orchids available in Nagaland are as follows, Thunia 1 spp, Arundinariagraminifolia (Bamboo orchid), Renenthera (Red vanda), ,Rhynchostylis (fox tail), Pleoni, Phauis (ground orchid) 2 spp, Paphiopedilum 1 spp, Cymbidium tigrinum 1 spp. The Govt. is taking measures for propagation of conservation and protection of these spp. through different afforestation schemes.
FAUNA
The largest Asian mammal, Elephant is endangered spp. The other endangered spps are Melursesursinus (Sloth Bear), Prionodonpardicolor (Spotted linsang, Tiger-civet), Pantheratigris (Tiger),Macacaassamensis (Tailed Pig).
The Gaur, or Indian Bison in habitats in Intangki National Park and Fakim Wildlife Sanctuary and other hilly areas are facing extinction from Nagaland The different Hornbills and Tortoise are also endangered.
Biodiversity of Tripura
Tripura being a part of North-East India, belongs to one of the two “Hot Spot” of India amongst 18 identified in the World. Hot Spots are designated on the basis of evidence of present-day distribution, diversity and linkages of crop plants/ horticultural plants, with the past; Hot Spots are the original homeland for the evolution and distribution of such plants.
At the ecosystem level, the State exhibits a part of the Mountain ecosystem with moderate hill ranges and forest ecosystems. In between these two dominant ecosystems lies the freshwater ecosystem comprising 10 major rivers, numerous wetlands. Undulating high lands of narrow and broken plates cover extensive areas
The diversity at the species level is largely determined by ecosystem diversity, which in turn is closely linked with soil and climatic condition. The species diversity of Tripura is largely known from Floral and Faunal diversity studies.
Fauna
The first scientific survey by Aggarwal and Bhattacharjee in 1977 documented 31 species and sub-species of mammalian fauna in the State. Bhattacharjee and Chakraborty (1986) recorded 56 mammalian species belonging to 9 Orders and 20 Families. The latest estimate by them put the number of land mammal species at 90, from 65 genera and 10 Orders. These constitute about 19, 48 and 100% of the total species, genera and orders of land mammals in India. Of a total of 15 species of non-human primate in India, 7(46.70%) are documented from Tripura. These also include some of the highly rare, endemic and endangered species, viz., Hoolock gibbon, slow loris, capped langur, Phayre’s langur, stump-tailed macaquae and pig-tailed macaque. The other endangered and threatened mammalian species in Schedule 1 of Wildlife(Protection) Act, 1972 are elephant, sloth bear, Indian wolf, Binturong, leopard, marbled cat, leopard cat, Chinese pangolin and serrow, etc.
Seven primate species have been documented in Tripura out of a total of 15 found in India. Of these primates slow loris and stumped tailed monkeys have become rare. Phayre’s leaf monkey (locally known as ‘Chashma Banar’), has a very restricted distribution in India, and is found in Tripura. Hoolock Gibbon is the only ape found in India, and its population has been rapidly dwindling in Tripura.
Ornithofauna comprises 342 reported species in the State. The migratory birds are reported to be 58 species. There is high diversity of birds of prey, frugivorous birds, marsh birds and flowerpeckers. In the aquatic ecosystem, 47 species of fish have been recorded. Due to silting of river beds and filling up of wetlands, different species of marsh birds and fishes are on the decline.
Survey has revealed that about 10% of plant species and 21% of mammals are currently endangered. The cause includes habitat loss and fragmentation, invasion by exotic, over-exploitation of resources and deforestation.
The total number of orders, families, genera and species of mammalian fauna in Tripura, which are included in Schedule 1 of the Wildlife (Protection) Act, 1972 are 5(50%), 12(41%), 14(22%) and 18(20%) respectively. Similarly, 4(40%), orders 9(31%) families, 10(15%) genera and 14(15%) species of land mammals in Tripura.
Flora
The range of floral diversity for a small state like Tripura appears significant from the fact the nearly 1463 of the 17,000 species or 8.6% Angiosperms (Flowering plants) known from India is recorded in Tripura (0.3% land of India). A total of 1546 species other than Bacteria, Fungi, Mosses, etc. belonging to 862 genera and 192 families of Flora have been recorded of which 86% are widely distributed in India and adjoining countries. It is also interesting to note that the ratio of Monocot : Dicot species for Tripura is much higher than for India.
Phytogeagraphically, Tripura belongs to the sub-zone Northern Burma which includes Mizoram, Chittagounj Hills in Bangladesh and Arakan in Myanmar, besides the Andaman Islands. While a strong affinity with flora of Eastern Himalaya can be noted, absence of Alpine flora of Abies, Jumperus, Larix, Picia and Tsuga is conspicuous; this can be attributed to climatic and altitudinal differences which are conducive for such floral growth. On the other hand, a palm species in Nepal and Sikkim is also recorded in Hilly terrain of Tripura.
Within the State, flora of northern region shows close affinity with adjacent Barak valley flora of Assam and Sylhet area of Bangladesh. Of the other areas, Sabrum region especially shows a close affinity with flora of Chittagong district of Bangladesh
Biodiversity of Sikkim
The State is endowed with rich floral and faunal diversity. Species wise, the State harbors over 5500 flowering plants, 557 Orchids, 38 Rhododendrons, 16 Conifers, 28 Bamboos, 362 Ferns and its allies, 9 Tree Ferns, 30 Primulas, 11 Oaks, 1681 Medicinal plants, 144+ mammals, 568 Birds, 48 Fishes, and over 689 Butterflies and 7000 species of Moths. While these figures are still not absolute, it is obvious that this is only the mega-fauna and flora.
The tremendous diversity of insects like beetles and moths as well as a host of other life forms is yet to be enumerated. Most of the high altitude medicinal plants are rare and endangered species. Sikkim also has 28 Mountains/Peaks, more than 80 Glaciers, 534 high altitude lakes/wetlands and over 104 rivers and streams.
Nature has been particularly generous in her gift of sylvan treasures to the state of Sikkim. Luxuriant forest, abound in all parts of state and variety of medicinal plants, herbs, shrubs, bamboos and trees growing in the state is truly rich. In the forest, there is a number of plants whose medicinal values have been well recognized by local people as well as by different pharmaceutical, insecticidal and perfumery sectors.
Medicinal plants ought to be given the status of a “National Resources” because their sustained availability is essential to sustain one of the world’s oldest medicinal traditions, a priceless legacy of the Indian people. The local inhabitants for the treatment of various ailments use numerous herbal remedies.
Furthermore, modern medicines owe to the flora of these mountains. Many inhabitants for treatment of various ailments use numerous herbal remedies. Many species of Himalayan origin have revolutionized the allopathic systems of medicine.