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Natural Vegetation

Natural Vegetation

Introduction

  • Before studying vegetation, let us note the difference between flora, vegetation and forest. Flora refers to plants of a particular region or period, listed as species and considered as a group. Vegetation on the other hand refers to the assemblage of plant species in a given environmental frame or ecological frame. Natural vegetation includes that part of the plant life which grows in wild without human aid and adapts to the constraints of natural environment in size, structure and requirements. Thus cultivated crops and fruit orchards form part of vegetation but not natural vegetation. All that grows naturally in different environmental and ecological settings constitutes natural vegetation. Finally, the word ‘forests’ is used, often loosely by administrators and general public to denote a large tract covered by trees and shrubs.
  • Natural vegetation refers to a plant community which has been left undisturbed for a long time. And that part of the natural vegetation which has remained undisturbed by humans is referred as virgin vegetation. Virgin vegetation in India can be found in accessible parts of the Himalayas, in Thar Desert and Sundarbans. Elsewhere the human occupation has either transformed natural vegetation into cultivated vegetation or degraded the natural vegetation.
  • As stated earlier, natural vegetation adapts itself to the factors of natural environment such as altitude, relief, weather, climate, etc. Natural environment varies from place to place and therefore natural vegetation too it differs widely. India being a land of great natural contrasts; it has a great variety of natural vegetation. The Western Ghats have tropical lush green forests; Himalayan heights are marked with temperate vegetation. The deltaic regions have tropical forests and mangroves; desert and semi desert areas of Rajasthan are known for Khejri trees and wide variety of bushes and thorns. And elsewhere there are different grades of forests depending upon variations in climate, especially the rainfall. The vegetation thus changes from tropical to subtropical and then temperate and finally to alpine on the, slopes of the Himalayas. Similarly it varies along the Western Ghats and in Nilgiris. The nature of vegetation even varies between western and eastern Himalayas, the western and eastern slopes of Western Ghats and the northwestern plains and middle and lower Ganga plains.

Types of Indian Vegetation

There are various ways of classifying Indian forests. In simplified version, they can classified as below:

THE TROPICAL EVERGREEN FORESTS

  • These are found in regions of very high annual rainfall exceeding 300 cm with a very brief dry season. It is found in parts of Western Ghats of Kerala and Karnataka and certain areas of Northeastern Hills and Andaman and Nicobar Islands. These forests resemble the equatorial vegetation. These forests are dense and have lofty evergreen trees, often as high as 60 m and above. Undergrowth is very dense and thick. Patches of canes, palms, bamboos, ferns, lianas are interspersed near streams or open areas. Grass is almost absent. These forests have very rich biodiversity. The number of vegetal species per unit area is too large to exploit them commercially. Mahogony, cinchona, bamboos and palms are typical species of plants found in these forests. The wood of these trees is very hard and heavy to work with. This type of vegetal cover has been badly depleted due to overcutting of trees. Tropical dry evergreen forests are confined to coastal Tamil Nadu which receives rainfall from retreating southwest monsoon and north-east monsoon.

TROPICAL SEMI-EVERGREEN VEGETATION

  • Tropical Semi-evergreen Vegetation is found between wet evergreen vegetation and moist temperate deciduous vegetation. This type of vegetation is found on the Sahyadris, Meghalaya plateau and Andaman and Nicobar Islands. This vegetation is confined to areas receiving an annual rainfall of about 250 to 300 cm. The vegetation cover is less dense than the wet evergreen forests. Rosewood, aini and telsur are important trees in Sahyadris; champa, joon and gurjan in Assam and Meghalaya and ironwood, ebony and laurel grew in other regions. Timber of these forests is fine textured and of good quality. Shifting agriculture and over exploitation of forests have depleted this vegetal cover to a great extent.

TROPICAL MOIST DECIDUOUS VEGETATION

  • This type of vegetation is found in areas receiving annual rainfall of 100 to 200 cm. These include the Sahyadris, areas of Chhota Nagpur plateau and Odisha, Himalayan foot hills in the Shiwaliks and terai. The deciduous trees shed their leaves once in a year during hot and dry season. Deciduous vegetation means the trees shed their leaves once in a year in dry season. Moist deciduous forests have dense undergrowth. It consists of large number of commercially important species such as teak, sal, sandalwood, shisham, cane and bamboo. As with all kinds of forests, these forests too are suffering from deforestation for timber, mining, agriculture, etc.

 TROPICAL DRY DECIDUOUS FORESTS

  • The dry deciduous is actually a variant of moist deciduous type having a lesser rainfall between 70 cm and 100 cm annually. The dry deciduous forests have a more open and dwarfish composition. Stretches of open grass between groups of trees are common and their drying during late winter and summer season gives these forests a barren look. The trees are more stunted and widely spaced called as ‘Parkland landscape’. These are also called the savannahs of India. The tree species in both moist and dry deciduous forests are more or less similar. Some of important varieties are Sal, teak, shisham, sandalwood, rosewood, hurra, myrobalan, mahua and khair.

TROPICAL THORN FORESTS

  • The zone adjacent to Dry tropical forests having rainfall below 75 cm is occupied by tropical thorn forests. These include semi desert and desert forests. They cover extensive areas in northern and northwestern part of the country and along the rain-shadow side of the Sahyadris. An open stunted forest which gradually degenerates into desert shrubs and grasses characterize these forests.
  • Excessive grazing and human interference in dry deciduous forests (degraded Savannahs) have often converted them into tropical thorn forests. The common tree varieties include neem, shisham, khair, pipal, babool, bamboo and khardhai. The western margin of this type of vegetation in the northwest India merges with sandy Thar Desert which has extremely sparse and thin vegetation cover like Tussocky grass and Khejri, babul, acacia, euphorbias, cactus, etc.

WETLANDS LITTORAL AND SWAMP FORESTS INCLUDING TIDAL (MANGROVE) FORESTS

  • The wetlands of the country include following varieties: lagoons like Asthamudi, Chilka, Pulicat; lakes and reservoirs like Sambar, Hirakud; the floodplains such as that of Brahmaputra and river deltas like Brahmaputra, Ganga, Godavari, Krishna, Kaveri; Marshes and Swamps as in northeastern hills, Kerala (myristica swamps) and mangrove forests along east and west coast and the islands of India.
  • The mangrove or tidal forests grow along the coasts in the salt marshes, tidal creeks, mud flats and estuaries. They consist of number of salt tolerant species of plants. Crisscrossed by creeks of stagnant water and tidal flows, they act as breeding ground and shelter for a wide variety of fishes and birds. The mangrove forests in India constitute 7% of world’s mangrove forests and 0.06% of India’s overall forests.
  • They are highly developed in Andaman and Nicobar Islands and Sundarbans of West Bengal as well as in Mahanadi, Godavari and Krishna deltas. Sundari is the typical tree of tidal forests found in Sundarbans. The wood of mangrove forests is hard and durable and often used for boat making. These forests are being encroached upon due to urbanization and industrialization and hence need conservation.

MONTANE VEGETATION – PENINSULAR

  • These are wet evergreen, semi evergreen and moist deciduous forests. These are found up to 1500 m height in Nilgiri and Palni hills in the south, higher slopes of Sahyadris and summits of Satpura and Maikal ranges. The wet temperate forests, locally known as ‘Sholas’, occur above 1500 m height on the south Indian hills of Nilgiris, Annamalai and Palni. Shola forest is dense but low with much undergrowth and many epiphytes, ferns, mosses. The common tree varieties include magnolia, laurel, rhododendrons, elm, cinchona, eucalyptus, etc. The peninsular montane vegetation is biodiversity rich vegetation and is one of the biodiversity hotspots along with Himalayan and North-eastern hills. It is also included in World Natural Heritage list.

MONTANE VEGETATION – HIMALAYAN

  • The vegetation in Himalayas undergoes changes depending on altitude, latitude and aspect. As a result the vegetation types are different on lower and higher slopes as well as eastern and western Himalayas.
  • Moist Tropical Deciduous forests
    • They are found in eastern Himalayas and along the foot hills in the Shiwaliks between 1000-2000 m height. Climbers and epiphytes may occur along with evergreen oak, chestnut, ash and peach.
  • Moist Temperate
    • The Wet Temperate Evergreen forests are found in entire Himalayan belt at 1500-3000 m height, receiving between 100 cm to 250 cm rainfall annually. These are very thick forests of lofty trees. In eastern Himalaya this vegetation is in the form of broad leaved evergreens with oak and chestnut being the predominant trees. Important tree varieties include chir, pine, cedar, silver fir, spruce, deodar, maple with some undergrowth of oak, rhododendrons, laurel and bamboo. These woods are durable. Sal is the important tree in lower altitudes.
  • Dry Temperate
    • This vegetation occurs in inner Himalayan ranges where rainfall is below 100 cm. It is found in Jammu and Kashmir, Lahaul – Spiti valley, Chamba, Kinnaur (Himachal Pradesh) and Sikkim. These are Coniferous forests with shrubs. Important varieties are deodar, oak, chilgoza, ash, maple, olive, mulberry, willow, celtis, etc.
  • Alpine vegetation
    • These forests too are found along entire Himalayas at 3000-3500 m heights. Alpine forests degenerate into dwarf conifers and lush grasses on southern slopes and dry xerophytic vegetation on the northern slopes of the Himalayas. Important tree varieties are silver fir, juniper, pine, birch and rhododendrons.

THE GRASSES

  • Pastures and grasslands are products of dry semi deserts but they have often resulted from degradation and destruction of forests into savannas. True pastures are found only in the Sub Alpine and Alpine areas in the Himalayas. They are also found under tree crops and groves, waste land and fallow land. The grass cover in India is of three types — the tropical, found in the plains, and the ‘subtropical’ and the ‘temperate’ both found in Himalayas. There are other ways to classify forests.

LEGAL OR ADMINISTRATIVE CLASSIFICATION:

  • Reserved Forests: These forests are under direct supervision of the government and no public entry is allowed for collection of timber or grazing of cattle. About 54% of total forest area is designated as Reserved Forest.
  • Protected Forests: These forests are looked after by government but the local people are allowed to collect fuel wood/timber and graze their cattle without causing serious damage to the forests. These occupy 29% of total forest area.
  • Unclassified Forests: These are those forests where there is no restriction on cutting of tree and cattle grazing. They have an area of 18%. Natural Vegetation

CLASSIFICATION ACCORDING TO BROAD TYPE OF VEGETATION

  • Coniferous Forests are confined to Himalayan ranges and provide soft wood timber. Natural Vegetation
  • Broad Leaved Forests widely spread and cover 95% of total forest area. Sal, Teak and Bamboo are important varieties.

FOREST COVER IN INDIA

  • As per definition ‘Recorded Forest Area’ is the area recorded as forest in the government records. Recorded forest area largely consists of reserved forests and protected forests as per the Indian Forest Act, 1927. According to Government of India, forest covers 22.50% of total land area of the country. Of these dense forests cover 11%, the open forests cover 7% and remaining is degraded. There is difference between forest area and actual forest cover. Forest Area is area notified and recorded as forest land irrespective of existence of trees. The Forest Cover, by definition, is all lands more than one hectare in area, irrespective of its ownership status, with a tree canopy density of 10 percent. The former is based on the records of State Revenue Department, while latter is based on aerial photographs and satellite imageries. In 2005, total forest area was 22.50% while actual forest cover was only 19.39%. Of the total forest cover, the reserved and protected forests shared 54% and 29% respectively. The following table gives an idea about the tree cover in India. Natural Vegetation

Forest Tree-cover

Year Area (in Ha) Change   over

previous period

%             change   over

previous period

1989 662803    
1991 662308 -495 -0.07
1993 662334 26 0.00
1995 660273 -2061 -0.31
1997 659550 -723 -0.11
1999 664737 5187 0.79
2001 668806 4069 0.61
2003 686767 17961 2.69
2005 690171 3404 0.50
2007 690899 728 0.11

 

  • The forest cover has been changed over the years due to the reforestation policies of the government from time to time. At the same time, 954,839 Hectares of forest area (from                the recorded forest area) have been diverted for non-forest use during 1980 and 2004.
  • Both forest area and forest cover (percentage) varies from state to state. Percentage-wise forest cover is as follows:
    • More than 40% — Andaman & Nicobar Islands (86.93%), Mizoram (83%), Arunachal Pradesh (81%), Nagaland (80%), have more than 80% forest cover.
    • 20% to 40% — Peninsular States except Tamil Nadu.
    • 10 — 20% — Uttar Pradesh, Himachal Pradesh, Bihar, Odisha, West Bengal, Tamil Nadu, most of the land in these States is under agriculture and habitation.
    • Less than 10% — Most of the States lie in northwestern part of the country. While forests in Punjab, Haryana are cleared for cultivation, Rajasthan, Gujarat and Haryana are semi-arid States.
  • Area-wise sequentially Madhya Pradesh, Arunachal Pradesh, Chhattisgarh, Odisha and Maharashtra have the largest forest area. Haryana and Lakshadweep have lowest forest area. The main natural regions of Indian forests are Himalayan Mountains, North-east region, central India and Western Ghats. Forests do not follow political boundaries. Natural Vegetation

PROBLEMS OF INDIAN FORESTS

  • Low forest cover and decreasing further — only 22.5% of the total land area against world average of 34% and the stipulated 33% under National Forest Policy, 1952. Forest area is decreasing due to deforestation on account of:
    • Growing demand for agricultural land
    • Urbanization and industrialization
    • Construction of multipurpose projects
    • Commercial activities like mining, quarrying, plantation, orchards, etc.
    • Shifting cultivation, overgrazing of cattle, trans-humance i.e. seasonal migration by nomadic tribes up and down the mountains.
  • Uneconomic utilization of forests :
    • Most of the forests are not gregarious i.e. usable plants not growing close enough. This creates problem in their exploitation.
    • 40% of the total forest area is inaccessible.
    • Lumbering, transport and sawing of timber is still done by primitive techniques.
    • Lack of scientific techniques of growing forests as in Canada, Russia. Only natural growth of forests takes place in India.
    • Forest Fires — Natural and manmade.
    • Plant diseases, pests, insects, etc. Natural Vegetation

CONSERVATION OF FORESTS | Natural Vegetation

  • According to National Remote Sensing Agency, India is losing about 1.3 million ha of forests cover every year. Continued exploitation of forests is damaging forest ecosystems, causing soil erosion and recurrent floods. The conservation measures to make forests healthy and sustainable can be understood though National Forest Policy.

NATIONAL FOREST POLICY

  • The first National Forest Policy of 1952 aimed at bringing one third of total land area, with 40% in hilly and 25% in plains; under the forest cover. It suggested extension of tree lands on river/canal banks, roads, railways, culturable waste and degraded lands. Natural Vegetation

A NEW NATIONAL FOREST POLICY WAS ADOPTED IN 1988. IT AIMED AT —

  • Restoring ecological balance and environmental stability.
  • Conserve biological diversity and genetic pool.
  • Check soil erosion, extension of desert land and reduction of floods and droughts.
  • Increase forest cover through social forestry and afforestation on denuded and unproductive land.
  • Increasing productivity of forests to provide timber, fuel, fodder, food to rural and tribal population dependent on forests.
  • Encourage substitution of wood.
  • Massive people’s movement involving women to encourage planting of trees. Stop felling of trees and reduce pressure on existing forests.
  • Several laws have been passed by legislatures to regulate the use of forests, ban on cutting of trees and encroachment on forest lands. Forest Conservation Act, 1980 was passed for reserved forest areas. Environmental Protection Act gave the Central Government polders to protect and improve the quality of environment and prevent pollution. Besides international convention like Reducing Emissions through Deforestation and Degradation plus (REDD+) help to set guidelines. Natural Vegetation

SOCIAL FORESTRY | Natural Vegetation

  • Social forestry means trees planted by people of society. It was suggested by National Forest Policies as well as National Commission on Agriculture, 1976. The main objective of social forestry is to reduce pressure on traditional forests by plantation of trees on farms and community lands and simultaneous production of food, fodder, fuel, fibre (timber) and fruits.
  • Social forestry programmes have mainly three components: These are: urban forestry, rural forestry and farm forestry.
    • Rural forestry — It lays emphasis on promotion of agro-forestry and community-forestry.
    • Agro forestry — Agro-forestry involves encouraging farmers to the raise of trees and agriculture crops simultaneously, on the same land.
    • Community forestry — It involves trees planted on community lands, by community themselves to be shared equally by them. Community or public land could be village pasture and temple land, roadside, canal bank, strips along railway lines, and schools etc. Community forestry provides a means under which the people of landless classes can associate themselves in tree-raising and thus, get those benefits which otherwise are restricted for landowners.
  • Farm forestry involves growing of trees for commercial and non-commercial purposes on farm lands.
  • Urban forestry pertains to the raising and management of trees on public and privately owned lands in and around urban centres such as green belts, parks, roadside avenues, industrial and commercial green belts, etc. However, the Social Forestry Projects failed due to —
  • It did not involve women who were main beneficiaries.
  • Market oriented trees were planted thus communities and farmers seeing it as cash generating rather than basic need generating exercise. The wood ended up in urban and industrial uses rather than fuel and fodder needs of rural people.
  • Agro-forestry reduced land employment while absentee landlordism increased. Natural Vegetation

WILDLIFE

  • Lying at the confluence of African, European and south-east Asian biological systems. India possesses great diversity and number of plants, animals and birds species. However, their number is decreasing at alarming pace as the forest cover of India is shrinking rapidly. Also, the density of trees in forests is very low compared to the forests of other countries. Due to illegal poaching and continuous hunting of wild animals their numbers are dangerously decreasing. The demand for furs of big cats, tiger bones, rhino horns, deer musks which are used in medicines and aromatic substances, elephant ivories has threatened the existence of their whole species. Asiatic lion, clouded leopard, tiger, musk deer, rhinoceros, great Indian bustard, Nilgiri langur, python, vultures, etc. are the species in danger. In order to conserve wildlife, the Government of India passed the Wildlife (Protection) Act, 1972, based on the recommendation of Indian Board of Wildlife. Secondly, the protection of wild animals and birds subject was included in the concurrent list of Indian Constitution, thus laying responsibility on Centre and State both. To save the endangered species of animals, specialized projects are being implemented with International Co-operation (WWF, UNDP, UNEP, IUCN) as well as on standalone basis, such as ‘Project Tiger, 1973’, Operation Crocodile 1975, Project Rhinoceros 1987, Project Snow Leopard and Project Elephant (1988). In recent years, the protected area network of National Parks, Wildlife Sanctuaries, Biosphere Reserves and World Heritage Sites, is being increased.
  • National Park: A national park is relatively large area of one or several ecosystems that have not materially altered by human exploitation and occupation. Here, plant and animal species, geo-morphological sites, and habitats for special scientific education and recreation are preserved. Hunting and grazing are absolutely prohibited in national park. In fact, the human interference is totally prohibited.
  • Wildlife Sanctuary: A wild life sanctuary too is dedicated to protect the wildlife. But here, human interference is allowed in regulated manner. Grazing or movement of cattle is regulated, hunting without permission is prohibited. Therefore, we often find the local tribal communities living in vicinity or sometimes inside wildlife sanctuary.
  • Biosphere Reserves: Under UNESCO’s Man and Biosphere Programme, 15 biosphere reserves have been established. Their main objectives are —
    • To conserve and integrity of plants, animals, birds and microorganisms.
    • To promote research on ecological conservation and other environmental aspects.
    • To provide facilities for education, awareness and training.
    • These reserves include (1) Nilgiri in Tamil Nadu. Karnataka and Kerala; (2) Gulf of Mannar in Tamil Nadu; (3) Agasthyamalai in Kerala; (4) Simlipal in Odisha; (5) Pachmarhi i.e. Achanakmar – Amarkantak in MP-Chhattisgarh; (6) Kanha in Madhya Pradesh; (7) Rann of Kachchh in Gujarat; (8) Thar Desert in Rajasthan; (9) Keoladeo Ghana, Bharatpur in Rajasthan; (10) Nanda Devi in Uttarakhand; (11) Sundarban in West Bengal; (12) Nokrek in Meghalaya; (13) Manas Assam; (14) Kaziranga i.e. Dibru Saikhowa in Assam; (15) Dihang-Debang i.e. Namdhapa in Arunachal; (16) Kanchenjunga in Sikkim; (17) Great Nicobar in Andaman and Nicobar Islands.
    • Apart from this, India has 6 natural sites as World Heritage Sites having ‘Outstanding Universal Value’ as follows:
    • Kaziranga National Park (1985)
    • Keoladeo National Park
    • Manas Wildlife Sanctuary
    • Nanda Devi and Valley of Flowers National Parks (1988)
    • Sundarbans National Parks (1987)
    • Western Ghats (2012)
    • Natural Vegetation

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