Forest Eco-System

| Last Updated:: 12/12/2023

Forest Eco-System

Photo Source: Internet

FOREST ECO-SYSTEM

Assam, one of the biodiversity hotspots occupies a special place in North Eastern India. The floristic richness has prompted many a scholars to describe Assam as the “Biological Gateway” of North East and Cradle of flowering plants. The climatic conditions cause prevalence of not and highly humid weather in this part of country and coupled with heterogenic physiography make possible luxuriant growth of a number of plant communities imparting Assam a distinct identity phyto-geographically, many a species are endemic to this region and it is also the centre of origin for commercially important plants.

Forest Status:

Forest cover in the State (Area in Km²)

States	Geographical Area	Forest Cover 2013				Per Cent of GA	Change W.R.T ISFR 2011	Scrub
1	2	VDF	MDF	OF	Total	Per Cent of GA	Change W.R.T ISFR 2011	Scrub
Assam	78,438	1,444	11,345	14882	27,671	35.28	-2	182

Recorded Forest Cover:

· Recorded Forests : 27,671 sq. km.

· Percent of Geographical Area : 35.28%

Forest Classification:

§ Reserved Forest : 18,060 sq. km.

§ Protected Area : 3925 sq. km.

§ Unclassified : 8,958 sq. km.

§ Very Dense forest : 1,444 sq. km

§ Moderately Dense : 11,345 sq. km

§ Degraded/open forest : 14,882 sq. km

§ Non forest : 50,583 sq. km

(Source: Forest Survey of India, 2011)

Major Types of Forests:

Tropical Wet Evergreen,

Tropical Semi-Evergreen,

Tropical Moist Deciduous,

Sub Tropical Broad Leaved Hill,

Sub Tropical Pine and Littoral,

Swamp Forests.

Tropical Wet Evergreen Forests are found in the districts of Golaghat, Jorhat, Sibsagar, Tinsukia, Dibrugarh and in a narrow stretch in Lakhimpur and Dhemaji districts along foot hills. These forests also occur in the southern part of the State at lower elevations in Borail Range, and in Loharbund, Sonai, Longai and Dholia Reserve Forests in Cachar and Karimganj Districts.

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.

Forests in Southern Assam have, however, Dipterocarpus terbinatus(Garjan) in association with Mesua ferrea ( Nahar), Mesua floribunda ( Bolong)), Michelia glabra (Champ), Palaquium polyanthum (Kathalua) etc

One witness luxuriant growth of epiphytes and trees with fissured bark support magnificent ornamental orchids of Assam. Lianas, vines and climbers are plentiful twining round trees in middle canopy. Almost all the tree ferns of Assam growing majestically in these forests present a treat to the eyes. The undergrowth is dense with both low shrubs and herbs occupying the space. Canes, palms and bamboos grow along edges of forests.

Tropical Semi Evergreen Forests occur mostly in Hallangapar, Abhoypur, Dilli, Dhansiri, Kholahat, Mayong, Garbhanga, Rani, Mahamaya, Guma, Haltugaon, Kachugaon, Gali, Pobha, Ranga, Kakoi, Nauduar, Batasipur, Dohalia, Singla, Longai, Bhuban Pahar, Sonai, Barak and Inner Line Reserve Forests along Northern and Southern parts of the State.

These forests have mostly medium size trees with few large trees. Shrubs, lianas, climbers, orchids and ferns grow copiously. At the fringe bamboos and canes occupy the space.

Species association and frequency of their occurrence vary from forest to forest, but the ones commonly found are Actinodaphne obovata (Petarichawa), Aesculus species (Ramanbih), Artocarpus chama(Sam), Albizia species(Siris, Sau, Koroi), Anthocephalus chinensis (Kadam), Duabanga grandiflora (Khakan), Castonopsis species (Hingori, Dhobahingori, Kanchan),Dillenia indica (Ou-tenga), Bauhinia purpurea ( Kanchan), Lagerstroemia species( Jarul, Ajar,Sidha), Magnolia species(Phulsopa, Gahorisopa, Pansopa, Kharikasopa, Kathalsopa, Duleesopa),Mallotus species( Sinduri, Joral, Dudhloti, Buritokan), Michelia champaca(Teeta campa), Syzygium species( Paharijam, Mokrajam, Berjamu, Kolajamu, Bogijamu, golapjamu). Schima wallichii (Bolem,Ghugra), Terminalia species, ( Hilikha, Bohera, Bhomora), Trewia nudiflora( Bhelkor), Hatipolia, Holok etc.

Moist Deciduous Forests can further be described as Sal Forests and Mixed Deciduous Forests. Sal Forests occupy considerable forest area in the Central and Lower parts of the State in the Districts of Nagaon, Morigaon, Kamrup, parts of Nalbari and Barpeta, Darrang, Dhubri, Kokrajhar and Goalpara.

In these forests, Sal grows in association with Lagerstroemia species( Jarul, Ajar), Schima Wallichii( Ghugra), Stereospermum personatum (Paruli), Adina cordifolia (Haldu), Artocarpus species ( Sam), Ficus species( Bor, Dimoru, Dhupbor, Bot, Athabor, tengabor, Lotadioru, Khongaldimoru), Bischofia javanica (Uriam), Gmelina arborea (Gomari), Michelia champaca(Teeta champa), Terminalia species (Hilikha, Bhomora, Bohera). Toona ciliate (Poma) etc.

Moist Deciduous Mixed Forests occur at the foot of hills in Lakhimpur, Dhemaji, Karbi-Angong and N. C. Hills districts. Trees are mostly deciduous with Sprinkling of few evergreen and semi-evergreen species. Important plant species growing in these forests include Adina cordifolia9 Haldu), Albizia species(Siris, Kolasiris, Koroi, Sau) Alstonia scholaris(Satiana), Artocarpus chama (Sam), Careya arborea( Kumbhi), Dalbergia species(Sissoo, Medelua), Ficus species (Bot, Bor, Dimoru), Lagerstroemia species (Jarul, Ajar), Mallotu species (Senduri, Joral, Dudhloti) etc.

These forest harbour rich diversity of shrubby and herbaceous ground vegetation. Some of the Reserve Forests also have teak plantations.

Bordering Moist Deciduous Forests in rain shadow areas are found forests which has been referred to as “Dry Forests” by Kanjilal. This type of forests are encountered in the Lumding, Langting, Mailongdisa Reserve Forests. A typical example is the Umananda Island in the middle of Brahmaputra North of Guwahati. Important species include, Aegle marmelos(Bel), Albizia species(Siris), Cassia fistula(Sonaru), Bombax (Simul), Alstonia scholaris(Satiana), Ficus species(Bor), Litsea species( Loban, Bagnola, Mezankori, Honwalu,Digloti) Melia azedarach( Neem), Moringa oleifera(Sajana), Orosylum indicum(Bhatgila), Mallotus species(Senduri), Terminalia species(Hilikha,Bhomora) etc.

Sub-tropical Broad Leaf Hills forests and Sub-tropical Pine forests occur in the districts of Karbi-Anglong and N. C. Hills. Species commonly occurring are Alseodaphne petiolaris(Ban-hanwalu), Antidesma bunius, Betula alnoides, Cleidon speciflorum etc. Higher up pure stands of Pinus kesiya(Khasi-pine) are found particularly in the Hamren sub-division in Karbi-Anglong district.

Grass land and Savannahs are grass dominated biomes and form the major part of vegetation in Kaziranga National Park, Pobitora, Orang, Sonai-Rupai, Laokhowa, Barnadi, Burachapori, Dibru-Saikhowa Wildlife Sanctuaries and some part in Manas National Park. Grasslands support important wildlife population in Assam. Important grasses are Apluda mutica, Phragmatis karka, Sclerostachya fusca, Saccharum species etc. These species grow gregariously at the onset of monsoon and grow even upto 6 meters tall.

Littoral and Swamp forests have almost lost their identity because of biotic pressure on land. Presently sedges and grasses form the largest component of vegetation. Important species include Ageratum conyzoides, Alocasia species, Alpinia species., Amaranthus species., Bacopa species., Blumea species., Bombax species., Crotolaria species. etc.

Recorded Forest Area

The recorded forest area of Assam is 26,832 sq km accounting for 34.21% of its geographical area. According to their legal status, Reserved Forests constitute 66.58% and Unclassed Forests 33.42% of the total forest area.

Protected Areas

The protected area network of Assam includes 7 National Parks and 18 wildlife sanctuaries covering an area of 0.40 million ha constituting 4.98% of the geographical area. The state has three Tiger Reserves, namely Kaziranga, Manas and Nameri. Kaziranga National Park and Manas Wildlife Sanctuary are in the list of World Heritage sites.

Forest Cover in Different Forest Types:

Forest type mapping using satellite data has been undertaken by the Forest Survey of India with reference to Champion and Seth Classification. As per this assessment, the state has 18 forest types belonging to five forest type groups viz Tropical Wet Evergreen, Tropical Semi Evergreen, Tropical Moist Deciduous, Tropical Dry Deciduous and Sub Tropical Pine Forests.

Forest and Tree Cover

The estimated tree cover in the state is 1,564 sq km which is1.99% of geographical area of the state. Forest cover in the state is 27,673 sq km that is 35.28% of the geographical area of the state. Thus the Forest and tree cover in the state is 29,237 sq km which is 37.27% of the geographical area. Source: India State of Forest Report 2011, Forest Survey of India.

Assam Forest Protection Force Act 1986

Assam Forest at a Glance 2011-12

Assam Settlement of Forest Coupes and Mahals by Tender System Rules 1967

Rules Having the Force of Law and Executive Orders Relating to Forests

Rules and Orders in Force in Certain Districts

Forest Regulation 1891

Assam Bamboo Policy

Database:

Reserve Forest of Assam

Forest Report of Assam 2011

Forest Division wise area under Forest in Assam 2007

Forest Division wise area under Forest in Assam 2008