India Physical Environment-Class XI (CHAPTER 5-NATURAL VEGETATION)

refers to a plant community that has been left undisturbed over a long time, so as to allow its individual species to adjust themselves to climate and soil conditions as fully as possible.

  • Himalayan heights are marked with temperate vegetation;
  • the Western Ghats and the Andaman Nicobar Islands have tropical rain forests,
  • the deltaic regions have tropical forests and mangroves;
  • the desert and semi desert areas of Rajasthan are known for cactii, a wide variety of bushes and thorny vegetation

TYPES OF FORESTS

(i) Tropical Evergreen and Semi Evergreen forests

(ii) Tropical Deciduous forests

(iii) Tropical Thorn forests

(iv) Montane forests

(v) Littoral and Swamp forests.

Tropical Evergreen and Semi Evergreen Forests

  • found in the western slope of the Western Ghats, hills of the northeastern region and the Andaman and Nicobar Islands
  • found in warm and humid areas with an annual precipitation of over 200 cm and mean annual temperature above 22oC.
  • well stratified, with layers closer to the ground and are covered with shrubs and creepers, with short structured trees followed by tall variety of trees.
  • trees reach great heights up to 60 m or above. There is no definite time for trees to shed their leaves, flowering and fruition. As such these forests appear green all the year round. Species found in these forests include rosewood, mahogony, aini, ebony, etc. 

The semi evergreen

  • found in the less rainy parts of these regions. 
  • Such forests have a mixture of evergreen and moist deciduous trees. The undergrowing climbers provide an evergreen character to these forests. Main species are white cedar, hollock and kail The British were aware of the economic value of the forests in India, hence, large scale exploitation of these forests was started. The structure of forests was also changed. The oak forests in Garhwal and Kumaon were replaced by pine (chirs) which was needed to lay railway lines. Forests were also cleared for introducing plantations of tea, rubber and coffee. The British also used timber for construction activities as it acts as an insulator of heat. The protectional use of forests was, thus, replaced , thus, replaced by commercial use. 

Tropical Deciduous Forests 

  • These are the most widespread forests in India.
  • They are also called the monsoon forests.
  • They spread over regions which receive rainfall between 70-200 cm.
  • On the basis of the availability of water, these forests are further divided into moist and dry deciduous 

The Moist deciduous: 

  • forests are more pronounced in the regions which record rainfall between 100-200 cm.
  • These forests are found in the northeastern states along the foothills of Himalayas, eastern slopes of the Western Ghats and Odisha.
  • Teak, sal, shisham, hurra, mahua, amla, semul, kusum, and sandalwood etc. are the main species of these forests. 

Dry deciduous forest – 

  • covers vast areas of the country, where rainfall ranges between 70 -100 cm. found in rainier areas of the Peninsula and the plains of Uttar Pradesh and Bihar.
  • the dry season begins, the trees shed their leaves completely and the forest appears like a vast grassland with naked trees all around. 
  • Tendu, palas, amaltas, bel, khair, axlewood, etc. are the common trees of these forests.

Tropical Thorn Forests

  • in the areas which receive rainfall less than 50 cm.
  • These consist of a variety of grasses and shrubs. 
  • It includes semi-arid areas of south west Punjab, Haryana, Rajasthan, Gujarat, Madhya Pradesh and Uttar Pradesh.
  • plants remain leafless for most part of the year and give an expression of scrub vegetation.
  • babool, ber, and wild date palm, khair, neem, khejri, palas, etc. Tussocky grass grows upto a height of 2 m as the under growth.

Montane Forests

  • In mountainous areas, the decrease in temperature with increasing altitude leads to a corresponding change in natural vegetation.
  • Mountain forests can be classified into two types, the northern mountain forests and the southern mountain forests
  • The Himalayan ranges show a succession of vegetation from the tropical to the tundra, which change in with the altitude. Deciduous forests are found in the foothills of the Himalayas.

The southern mountain forests-

  • found in three distinct areas of Peninsular India viz; the Western Ghats, the Vindhyas and the Nilgiris.
  • As they are closer to the tropics, and only 1,500 m above the sea level, vegetation is temperate in the higher regions, and subtropical on the lower regions of the Western Ghats, especially in Kerala, Tamil Nadu and Karnataka.
  • The temperate forests are called Sholas in the Nilgiris, Anaimalai and Palani hills. Some of the other trees of this forest of economic significance include, magnolia, laurel, cinchona and wattle. Such forests are also found in the Satpura and the Maikal ranges

Littoral and Swamp Forests 

  • India has a rich variety of wetland habitats. 
  • About 70 per cent of this comprises areas under paddy cultivation.
  • Two sites — Chilika Lake (Odisha) and Keoladeo National Park (Bharatpur) are protected as water-fowl habitats under the Convention of Wetlands of International Importance (Ramsar Convention).
  • The country‘s wetlands have been grouped into eight categories, viz. 

(i) the reservoirs of the Deccan Plateau in the south together with the lagoons and other wetlands of the southern west coast;

(ii) the vast saline expanses of Rajasthan, Gujarat and the Gulf of Kachchh

(iii) freshwater lakes and reservoirs from Gujarat eastwards through Rajasthan (Keoladeo National Park) and Madhya Pradesh;

(iv) the delta wetlands and lagoons of India‘s east coast (Chilika Lake);

(v) the freshwater marshes of the Gangetic Plain;

(vi) the floodplains of the Brahmaputra; the marshes and swamps in the hills of northeast India and the Himalayan foothills;

(vii) the lakes and rivers of the montane region of Kashmir and Ladakh; and

(viii) the mangrove forest and other wetlands of the island arcs of the Andaman and Nicobar Islands. Mangroves grow along the coasts in the salt marshes, tidal creeks, mud flats and estuaries

FOREST COVER IN INDIA

  • the forest area covers 23.28 per cent of the total land area of the country.
  • It is important to note that the forest area and the actual forest cover are not the same. The forest area is the area notified and recorded as the forest land irrespective of the existence of trees, while the actual forest cover is the area occupied by forests with canopy. 
  • The former is based on the records of the State Revenue Department, while the latter is based on aerial photographs and satellite imageries. 
  • According to India State of Forest Report 2011, the actual forest cover in India is only 21.05 per cent.
  • Lakshadweep has zero per cent forest area; 
  • Andaman and Nicobar Islands have 86.93 per cent.
  • Most of the states with less than 10 per cent of the forest area lie in the north and northwestern part of the country. These are Rajasthan, Gujarat, Punjab, Haryana and Delhi.
  • there are 15 states where the forest cover is more than one-third of the total area, which is the basic requirement for maintaining the ecological balance.

FOREST CONSERVATION 

  • a forest policy in 1952, which was further modified in 1988. According to the new forest policy, the Government will emphasise sustainable forest management in order to conserve and expand forest reserve on the one hand, and to meet the needs of local people on the other.
  • The forest policy aimed at:

(i) bringing 33 per cent of the geographical areas under forest cover;

(ii) maintaining environmental stability and to restore forests where ecological balance was disturbed;

(iii) conserving the natural heritage of the country, its biological diversity and genetic pool;

(iv) checks soil erosion, extension of the desert lands and reduction of floods and droughts;

(v) increasing the forest cover through social forestry and afforestation on degraded land;

(vi) increasing the productivity of forests to make timber, fuel, fodder and food available to rural population dependant on forests, and encourage the substitution of wood;

(vii) creating of a massive peoples movement involving women to encourage planting of trees, stop felling of trees and thus, reduce pressure on the existing forest

Social Forestry

  • Social forestry means the management and protection of forests and afforestation on barren lands with the purpose of helping in the environmental, social and rural development. 
  • The National Commission on Agriculture (1976) has classified social forestry into three categories. These are Urban forestry, Rural forestry and Farm forestry.
  • 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
  • Rural forestry lays emphasis on promotion of agro-forestry and community-forestry. 
  • Agro-forestry is the raising of trees and agriculture crops on the same land inclusive of the waste patches. It combines forestry with agriculture, thus, altering the simultaneous production of food, fodder, fuel, timber and fruit.
  • Community forestry involves the raising of trees on public or community land such as the village pasture and temple land, roadside, canal bank, strips along railway lines, and schools etc.

Community forestry programme aims at providing benefits to the community as a whole. 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 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.

Farm Forestry

  • Farm forestry is a term applied to the process under which farmers grow trees for commercial and non-commercial purposes on their farm lands.
  • Forest departments of various states distribute seedlings of trees free of cost to small and medium farmers. Several lands such as the margins of agricultural fields, grasslands and pastures, land around homes and cow sheds may be used for raising trees under non-commercial farm forestry

WILDLIFE

Wildlife of India is a great natural heritage. It is estimated that about 4-5 per cent of all known plant and animal species on the earth are found in India. The main reason for this remarkable diversity of life forms is the great diversity of the ecosystem which this country has preserved and supported through the ages.

Some of the important reasons of the declining of wildlife are as follows:

(i) Industrial and technological advancement brought about a rapid increase in the exploitation of forest resources.

(ii) More and more lands were cleared for agriculture, human settlement, roads, mining, reservoirs, etc.

(iii) Pressure on forests mounted due to lopping for fodder and fuelwood and removal of small timber by the local people.

(iv) Grazing by domestic cattle caused an adverse effect on wildlife and its habitat.

(v) Hunting was taken up as a sport by the elite and hundreds of wild animals were killed in a single hunt. Now commercial poaching is rampant.

(vi) Incidence of forest fire

WILDLIFE CONSERVATION IN INDIA

  • In 1972, a comprehensive Wildlife Act was enacted, which provides the main legal framework for conservation and protection of wildlife in India. two main objectives of the- 1-to provide protection to the endangered species listed in the schedule of the Act and 2-to provide legal support to the conservation areas of the country classified as National parks, sanctuaries and closed areas
  • amended in 1991, making punishments more stringent and has also made provisions for the protection of specified plant species and conservation of endangered species of wild animals
  • There are 102 National parks and 515 wildlife sanctuaries 
  • Government of India in collaboration with UNESCO’s Man and Biosphere Programme‘ MAB
  • Special schemes like Project Tiger (1973) and Project Elephant (1992) have been launched to conserve these species and their habitat in a sustainable manner. 
  • Project Tiger 1973. The main objective of the scheme is to ensure maintenance of viable population of tigers in India for scientific, aesthetic, cultural and ecological values, and to preserve areas of biological importance as natural heritage for the benefit, education and enjoyment of the people. The tiger population in the country has registered an increase from 1,411 in 2006 to 1,706 in 2010. 
  • Project Elephant was launched in 1992 to assist states having free ranging population of wild elephants. It was aimed at ensuring long- term survival of identified viable population of elephants in their natural habitat. The project is being implemented in 13 states

BIOSPHERE RESERVES

  • A Biosphere Reserve is a unique and representative ecosystem of terrestrial and coastal areas which are internationally recognised within the framework of UNESCOK Man and Biosphere (MAB) Programme. The Biosphere Reserve aims at achieving the three objectives-
  • There are 14 Biosphere Reserves in India . Four Biosphere Reserves, namely

(i) Nilgiri;

(ii) Nanda Devi

(iii) Sunderbans; and

(iv) Gulf of Mannar have been recognised by the UNESCO on World Network of Biosphere Reserves.

Nilgiri Biosphere Reserve 

  • the first of the fourteen biosphere reserves of India, was established in September 1986.
  • It embraces the sanctuary complex of Wyanad, Nagarhole, Bandipur and Mudumalai, the entire forested hill slopes of Nilambur, the Upper Nilgiri plateau, Silent Valley and the Siruvani hills. The total area of the biosphere reserve is around 5,520 sq. km. 
  • The Nilgiri Biosphere Reserve possesses different habitat types, unspoilt areas of natural vegetation types with several dry scrubs, dry and moist deciduous, semi- evergreen and wet evergreen forests, evergreen sholas, grasslands and swamps.
  • It includes the largest known population of two endangered animal species, namely the Nilgiri Tahr and the Lion-tailed macaque.
  • good number of endemic and endangered plants are also found in this reserve.

Nanda Devi Biosphere Reserve

  • The Nanda Devi Biosphere Reserve situated in Uttaranchal includes parts of Chamoli, Almora, Pithoragarh and Bageshwar districts. 
  • The major forest types of the reserve are temperate. A few important species are silver weed and orchids like latifolie and rhododendron.
  • The biosphere reserve has a rich fauna, for example the snow leopard, black bear, brown bear, musk deer, snow- cock, golden eagle and black eagle.
  • Major threats to the ecosystem are the collection of endangered plants for medicinal use, forest fires and poaching.

Sunderbans Biosphere Reserve

  • It is located in the swampy delta of the river Ganga in West Bengal. 
  • It extends over a vast area of 9,630 sq. km and 
  • consists of mangrove forests, swamps and forested islands. 
  • Sunderbans is the home of nearly 200 Royal Bengal tigers.

In the Sunderbans, the mangrove forests are characterised by Heritiera fomes, a species valued for its timber

Gulf of Mannar Biosphere Reserve

The Gulf of Mannar Biosphere Reserve covers an area of 105,000 hectares on the southeast coast of India.

one of the world‘s richest regions from a marine biodiversity perspective. The biosphere reserve comprises 21 islands with estuaries, beaches, forests of the nearshore environment, sea grasses, coral reefs, salt marshes and mangroves. Among the Gulf‘‘s 3,600 plant and animal species are the globally endangered e.g. sea cow (Dugong dugon). Besides six mangrove species, endemic to Peninsular India are also endangered.

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