Flora of Tripura
The forests of tripura are varied. On the basis of large-scale studies in other North-Eastern States, Deb(1981) considered the classification of forest types suggested by Champion and Seth (1968) as better suited for describing and correlating the forest types in India. Deb’s description of the flora of tripura has been followed here.
Based on climate (also altitude and longitude), the forests of tripura are treated under tropical forest types.
Moist Deciduous Forest:
- Dipterocarpus turbinatus Gaertn., Artocarpus Roxb., A. heterophyllus Lamk., Cinnamomum glanduliferum (Wall.) Nees C. bejolghota Sw. Cryptocarya amygadalina Nees, Magnifera sylvatica Roxb., Aphanamixis polystachya (Wall.) Parker, Aglaia spectabilis Miq.,Schima Wallichii (DC) Korth., Actinodaphne angustifolia Nees, A. obvata B1.., Beildschmiedia assamica Meissn., Castanopsis indica ADC are common on the top canopy. In the more exposed drier regions and in areas where the forest has been subjected to shifting cultivation, deciduous or semi-deciduous plants like Bombax ceiba L., Terminalia bellirica(Castertn.) Roxb., T. myriocarpa Heu rck ex Muell., - Arg., Albizia procera (Roxb). Benth, Lagerstroemia speciosa (L)Pers., L. parviflora Roxb., IIex umbrella (wall) loses are common.
- Dysoxylum binectarderum Hook f.et. Bedd., Michelia champaca L., Mesua ferra I., Cinnamomum bejolghota Sw. Litsea glutinosa (Lour) C.B. Robinson, L. laeta (Wall. Ex. Nees) Hook. F.L.Panamouja (F.- Ham) Hook. F. persea villosa (Roxb), Kosterm., Phoebe attenuatta Nees, Pterospermum lanceaewfolium Roxb., Aquilaria malacensis Lamk, Toona cilita M. Roem., Hydnocarpus kurzil (King) Warb., Gynocardia odorata R. Br. Sterculia indica Merr., K.angustifolia (Roxb) Warb., K. malayana Warb., Ardisia colorata Roxb. A. paniculata Roxb. A neriiifolia Wall. Ex. ADC., Holigarna caustica Roxb. Ex. Gresh., Stereospewrmum personatum (Hassk) Chatterjee. Vitex penduncularis Wall. Ex. Schauer. Turpina pomifera DC., Alstonia scholaris (L) R. Br. Etc. along with smaller trees of the upper canopy are found in the second storey.
- Litsea cubeba (Lour) Pers., L. lancifolia Roxb. Ex.Nees., Neolitsea zeylancia (Nees) Merr., Phoebe lanceolata (Nees) Nees, Bambusa tulda Roxb., Dendrocalamus hamiltoniii Nees & Arn.
- Oxytenanthera albociliata Munro, Bambusa pallida Munr. Livistona chinensis R. Br. Syzygium cumini (l) Skeels. S. cerasoides (Roxb) Chatterjee et Kangi. F. Palaquium polyanthum Engl., Casearia kurzii C.B. Clerke etc. form this storey in places.
- Shrubby layer comprises Meliosma simplicifolia (Roxb.) Walp., Litsea meissneri Hook.F.L. salicifolia (Roxb. Ex. Wall). Hook.F. Maesa ramentocea (Roxb) A.D.C. Micromelum integerrimum ( F.-Ham. Ex DC) Wt. & Arn., Phlogacanthus thrsiflorus Nees. Strobilananthes capitatus T. Anders., S. scaber Nees Clausena heterophylla (roxb) Wt. & Arn., tree ferns and a very large number of other plants.
- Curculigo latifolia Dryand, C. Orchides Gaeertn., Phrynium capitatum Wild Begonia roxburghi A.D.C. B. Barbata Wall Ex. A.D.C. Alpinia allughas Rose., A bracteata Roxb., Wt. E. platyphyllum Wedd., E. rupstre Wedd. Hedyotis coronata Wall. Ex. Hook.f. Amaryllidaceae, Scitamineae, Commelinaceae, Rubiaceae., Araceae and many othersa form the ground layer. Aeiginetia indica L. a. saprophyte is very common.
- Dense masses of evergreen climbers like Entada phaseolodes (L). Merr., Bauhinia anguina Roxb. (fig.5) Acacia pruinescens Kurz, Beaumontia grandiflora (Roxb). Wall., Tetracera scandens (L) Merr., Rhaphidophra eximia Schott., R. decursiva (Roxb) Schott. Tetrastigma bracteolatum (Wall) Planch., Vitis tuberculata (BI) Laws, Calamus leptospadix Griff., Pothos scandens L.,P. cathcartii Schott., etc. are very common.
Orchids are common in the evergreen forest, Phajus tankervilliae (Alit.) BI., Apostasia wallichii R.Br. Hetaeria rubens Benth., tropidia angulosa BI. And Zeuxine strateumatica (L) Schltr. are scattered in the ground layer. Epiphytic orchids are more numerous than the terrestrial ones.
Frequency, dominance and association of species very often vary from one forest to another. In Damcherra Diperocarpus turbinatus Gaertn. F., Mesua ferra L., ilex godajum Colebr., Dysoxylem binectariferum Hook. f.et Bedd, Artocarpus chaplasha Roxb. Form consociations., whereas in the Jampui and Sakhan Ranges Schima wallichii Choisy, Gynocardia odorata R. Br., Hydnocarpus kurziii (King) Warb., Beilschmedia media assamica Meissn. Cryptocarya amygdalina Nees and others form associations.
The moist deciduous forests are characterized by the presence or absense of Sal and accordingly they may be acalled
- Sal forest or
- Moist deciduous mixed forest as the case may be
- Sal Forest: This occurs in southern region of the wstern low hill extending to the border of Bangladesh. It is found locally in Belonia, Udaipur, Sonamura and Sadar Sub-Divisions. Local variations occur in flouristic composition and aboundance of different species and in the storeyed arrangement in different areas. A general outline of the flouristic composition is given below. Shorea robusta Gaertn.f. is the ecologically characterestic and economically inportant species that dominates over 60 per caent of the top canopy. Dipterocarpus turbinatus Gaertn., Lagerstroemia parviflora Roxb., Gmelina arborea Roxb., Careya arborea Roxb. also occur.
Schima Wallichii (DC) Korth, Terminalia belliricia (Gaertn). Roxb., T. Chebula Retx, Stereospermum personatum (Hassak) Chatterjee, Vitex Peduncularis Wall. Ex. Schauer, Pterospermum semi sagittatum F. Ham, Ex. Roxb., P acerifolium Wild, Dilleia pentagyan Roxb., Syzygium cerasoides (Roxb) hatterjee et Kanji.f.Lagerstroemia parviflora Roxb., Garuga pinnata Roxb., Albizia chiensis (Osbeck) merr. A procera(Roxb.) Benth Lannea coromamdelica (Houtt) merr. Chukrasis tabularis. A Juss, Tonna ciliate M. Roem Sapium baccatum Roxb., Oroxylum(L) Vent., Protium serratum (Wall. Ex.Coleb) Engl. Etc. from the next canopy.
Phyllanthus emblica L., Mallotus phillippensis (lamk) Muel.,-Arg., Aporusa blonga (Wall) mule Arg.,Maesa rameentacea (Roxb) A.d.C., Cordia fragrantissina Kuez, Semecarpus anacardium L.f. Streblus as per Lour., Bridellia retusa Spreng. Antidesma bunius (L) Spreng., Macaranga denticulate (Bl.), Muel.Arg Bauhinia purpurpa L;B.Variegata L, Dsosylui binectariferun Hook. F. et. Bedd, Callicarpa arborea Roxb. Litsea monopetala (Roxb) Pers., Melliosma simpliciflora (Roxb) Walp., Microcos paniculata L. Syzygium Fruitcosum DC., Premna coriacea C,B Clarke, Zanthoxylum limonella (Dennst) Alst., Dalbergia stipulacea Roxb. D lanceobaria L. Millettia auriculata Baker ex Brandis. Dendrocalamus hamiltonii Nees & Arn. Bambusa pallida Munro, Oxytenanthera albociliata Murno etc., also occur in the second storey.
Butea parviflora Roxb. Dlahousiea bracteata (Roxb) R. grah byttneria pilosa Roxb. Stephania glandulifera Miers Combbretuym roxburghi spreng., Pueraria phaseoloides (Roxb) Benth, Mucuna nigricans (Lour) Steud., M.Pruita Hook., Smilax zeylanica L. Dioescorea bulbifera L.D. glabra Roxb., D. hamiltonii Hook.f. Cayratia japonica (Thumb) Gangnep., C. repanda Vahl., Vitis tuberculata (BI) Laws are the common climbers.
Meleastoma malbathricum L, Osbeckia chinesis L., O.nepalensis Hook., Clerodendrum viscosum Vent, Desnodium heterocarpon (L.) Dc., D. Caudatum (Thumb) DC., D, gangeticum (L) DC., Maughania stronbiliferum (L.) St. Hill ex Jackes, M. stricta(Roxb), O. Kuntze etc., from the shrubby layer.
Ground cover is formed of a large number of grasses and hedges. In rainy seasons herbs belonging to the families Commmelinaceae,Zingiberaaceae,Dioscoreaceae and a host of others grow.
Due to local edaphic factoes and biotic influences on certain localities particularly in Sonamura, tha Sal forest has been reduced to a secondary savannah, where much of the area has been brought under paddy cultivation by feeling the trees. Trees are stunted and crooked in form. Most of the plants appear to have come up from stumps. The forests are separated into northern and southern parts by about 6.4 km. of paddy land. The quality of wood appears to be slightli inferior in the northern part, probably due to difference in soil, Regeneration is good, but the seeding are mostly burnt away by annual fire.
- Moist Deciduous Mixed Forest: Moist deciduous mixed forest covers a large area of the forest in Amarpur, Sonamura, Udaipur and Sadar-Divisions and occurs in patches in Dharmanagar, Kailasahar and Kamalpur Sub-Divisions. This differs mailnly from the preceding one in the absence of Sal or in its scarcity. Dominants are mailnly deciduous, but sub-dominants and lower storeys are largely evergreen. Top canopy is not dense and even. It is about 18-25m. high. Differentiation in canopy layer, is not conspicuous.
- Schima wallichi (DC) Korth, Dilenia pentogyna Roxb, Terminalia bellirica (Gaertn) Roxb., Garuga pinnata Roxb., Lannea coromondelica(Houtt.) Merr. Buccania lanzan Spreng., Stereospermum personatum (Hassk.) Chatterjee. Pterospermumacerifolium Wild. P . semisagittatum F. Ham. Ex. Roxb., Laggerstroemia parviflora Roxb., Churaisa tabularis A. Juss Bombex ceiba L. Vitexpeduncularis Wall. Ex.Sachauer Hymenodictyon excelsum(Roxb.) Wall., Mitrangya rotandifolia (Roxb) O. Kuntze. Nauclea Sessilifolia Roxb. Dubanga grandiflora (Roxb) Walp. Gmelina arborea Roxb. Albizia (Roxb) Bnth, Elaecarpus prunifolia Wass ex. Mart., Sterculia villosa Roxb., Gardenia resinifera Roth, Erythrina arborescene Roxb, Sapium baccatum Roxb., Syzygium syzygiodes (Miq.) Merr. et. Perry. S. Cerasoides (Roxb) chatterjee et Kanj. F. Eugenia praecox Roxb. Constitute the top canopy.
- The second story is made up of the smallest trees of the first storey together with the following: Holarhen antidysenterica G.Don ex. A.DC Micros paniculata L., phyllanthus emblica L., Litsea cubea (Lour) Pers L, Iancifolia Roxb., Aesculus assamica Griff., xeromphis spinsa (Thumb) Keay, melocanna bambusoides trin, Stre blus asper Lour macaranga denticulate (BI) Muell-Arg., Mallotus aiba Muell-Arg., M. Phillipensis (Lamk) muel-Arg. Ardisia colorata Roxb., A. paniculata Roxb., Flacourtia indica (Burm.f.) Merr., Clerodendrum viscosum vent., maesa chista F. Ham- M.indica (Roxb.) A.Dc., Pogostemon parviflorus Benth.
At the exposed regions of the forest Phyllanthus emblica., Croton ablongifolius Roxb., Pandanus foetidus Roxb., Pandanus foetidus Roxb., P.furcutus Roxb., Aesculus assamica Griff., Mallotus philippensis (Lamk) Muell.- Arg., Clerodendrum viscosum Vent., Holarrhena antidysenterica G.Don ex A.Dc, Microcos paniculata L. Macarange denticulate (BI) Muell-Arg and others form associates.
Butea parviflora Roxb., Byttneria pilosa Roxb., Combreutum roxburghii Spreng., Pueraria phaseoloides (Roxb) Benth., Mucuna DC., M.nigricans(Lour) Steud., Elaeagnus conferta Roxb. Dioscorea bulbifera L.D. glabra Roxb., smilax zeylanica L. Argyreia cupitata (Vahi) Choisy, Coccinia cordifolia (L) Coga., Melothria heterophylla cogn., Thladiantha calcarata C.B. Clarke, Cissampelos pareira L. Stephania japonica (Thunb). Miers var. discolor(Miq.) Forman, Thunbergia grandiflora Roxb., Pothos scandens D.Don, Rhaphidophora eximia Schott R. lancifolia Schott., are very common.
Geound cover is formed of Desmodium triquetrum (L) DC., D. Caudatum (Thumb) DC. D. heterphyllum (Willd). Dc. Maughania strobilifera (L) St. Hill. Ex. Jacjes, M.stricta (Roxb) Kuntze, Costus speciosus (Koenig) Smith, Curcuma zedoaria Rose., and other Zinmgiberaceous plants and many others.
Mikania cordata (Burm. F.) Robins, an exotic climber is common in this forest. Eupatorium odoratum L. and E. cannabinum L, are fairly common. Towards the middle of the hot season, the deciduous trees shed leaves but they are not completely leafless and they are again in leaf before the monsoon. Mostly the trees and other woody species flower in the hot season. Rhizomatous and bulbous families like Liliaceae, Amaryllidaceae, Zingiberaceae send up their scapes and produce beautiful flowers in the rainy season. These form a characteristic undergrowth in the monsoon period.
Swamp locally called 'Lunga' occupy a very large area all over the State. Formation of these Lungas has (Deb, 1975) been discussed in connection with geology and soils.
It comprises mostly herbaceous species, some woody shrubs and a few scattered trees, Barringtonia acutangula (L) Gaertn. lagerstroemia pariviflora Roxb., Mallotus philipinesis (Lamk.) Muel- Arg., are the common trees. Phragmities karka (Retz) Trin., Alpinia aalughas Rosc., Saccharum spontaneum L., Erianthus arundinaceus (Retz.) Jeswiet Eleocharis plantaginea R. Br. E. ramulosa C.B. Clarke, Scripus supinus L. Cyperus compactus Retz., C. difformis L., Fimbristylis dichotoma (I.) Vahl., F. glomer ata kunth etc. are the common herbs.
In marshy or low lying places with shallow water table are very commonly found, sometimes in vast areas, Alppinia allughas Rose., A. bracteata Roxb., A galangal (L) Wild., A. malcaensis Rose, Imperata Cylindrica (L) P. Beauv., phragmites karka (retz) Trin. Ex. Steud., Erianthus arundinaceus (Retz.) Jesweit, E.Procerus (Roxb) Raizada and Saccharum spontaneum L. They form socies and grow in associes in various proportionsa probably depending on the condition of the soil and depth of water. Accordingly to the percentage of area covered by the individual species, they appear to form phragmites- Alpinia- Phragmitiers- Saccharum associates.
All the edges, rooted in the mud or floating or submerged in water are found, Melastoma malabathricum L. Osbeckia chinensis L. Ludwigia actovalvis sussp. Sessilliflora (Micheli) Ravan, L. prostrate Roxb., L. Clavellina Gomez et molionet, Euryale ferox Salisb., Nymphodes cristata (Roxb) O. KunzeTrapa natans L. Var. bispinosa (Roxb) Makin., Ottelia alismoides Lemma purpusilla Torr., Wolffia arrhiza (L) Wimm. Spirodela Polyrhyiza (I) Schleid, Vallisneria sprialis L., Hydrilla verticillata (I.f) Royle, Sagittaria sagtittifiolia L. Utricularia flexuosa Vahl, Eriocaulon cineremum R. Br. Polycarpon indicum (Retz) merr., Rotala indica (Wild) Koelme, Sphenoclea zeylanica Gaertn., Smithia sen sitiva Ait., Hydrolea zeylanica (L) Vahl. Limnophila sessilis (Benth) Fischer, Leersia hexandra Sw. Floscopa Lour Monochoria hastate (I) Solms and Polygonum hydropiper L.
Bamboo brakes widely in character and aspect cover very large areas in Tripura as in Burma and Chittagong. Continuous bamboo forests are interrupted with scattered evergreen treesor deciduous secondary stands. Sheltered hollows and other favourable sites are dominated by bamboo. The vast preponderance of bamboo forest may be the result of activity of man in his practice of shifting favourable for bamboo growth. It is also possible that bamboo holds the ground as a primary edaphic sub-climax.
About 1927 sq.km. of area is covered with 'Muli' Melocanna bambusoides Trin. In the valleys of Deo-Manu major rivers. Of the large numbers of bamboos occurring there only 19 species have so far been identified. Some of them are name below with the local names in the parenthesis: (I) Bambusa balcooa Roxb('Barak'), (2) B. nutans Wall. Ex munro('Kali') (3) B.pallida Menro('Makal') (4) B.polymorpha Munro ('Barua') (5) B. teres Ham. Ex Wall ('Parua') (6)B. tulda Roxb. ('Mirtinga') (7) Dendro calamus hamiltonii Nees & Arn. Ex Munro ('Pecha') (8) D.longispathus kurz ('Rupal') (9) Melocanna bambusoides Trim ('Muli') (10) Oxytenanthera nigrociliata Munro ('Kayal') and (11) Neohouzeaua dullloa, A. Camus('Dalu')
Fauna of Tripura
Wide variety of wild animals belonging to different groups are found in tripura. The richness of fauna could be attributed to its unique bio-geographical location and zoo-geographical position. Literature shows that there were large populations of rhinoceros, elephant, tiger, leopard, langurs and monkeys in tripura (Gupta, 2000).
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 (Gupta,2000). 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 (Gupta, 2000). 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 15 found in India. Of theseprimates 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 comprise 342 reported species in the State. The migratory birds are reported to be of 58 species. There is high diversity of birds of prey, frugivorous birds, marsh birds and flower peckers. 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 decline.
Survey has revealed that about 10% of plant species, and 21% of mammals are currently endangered. The cause include 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 also form a part of Appendix 1 of CITES.
Apart from the rich diversity of mammalian species, tripura could be regarded as one of the unique habitats for a large number of varied bird species, reptilians, amphibians, fishes and invertebrates very similar to the entire North-Eastern Region. Mathur et al., (1993) reported 341 species of birds in tripura .Among other notable species, a rare bird ‘Himalayan Sterling’. Which is killer of locusts is also found here. Though exact accounts are not available but large variety of snakes such as cobra, krait, viper, python, lizards geiko, frogs, toads and invertebrates are found in tripura. Zoological Survey of India has compiled the list and it is learnt that it will be published very soon. Photo Gallery>>
The Department of Life Sciences of tripura University has prepared a list a insect and earthworm fauna which are related to plants and animals (Agarwala,2001).
Domesticated animal species diversity
Domesticated animals and birds along with wild animals play an important role in ecological cycle and economic lifestyles of population. In tripura, 15 - 20 domesticated species are observed. Most of these species are indigenous, but over a period of time, exotic varieties have been introduced mainly because of high productivity.
It is observed from the table 55 that the population of different animals has grown by 0.5% to 4.6%. Though the population has increased but productivity and size of these animals has been reduced (ARDD, 2001). This is an alarming situation. Exotic varieties have been introduced and the programme of crossbreeding has been taken up by the government to improve the quality of local breed.