CBSE Class 11 Geography Natural Vegetation Notes

Natural vegetation

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 cacti, a wide variety of bushes and thorny vegetation. Depending upon the variations in the climate and the soil, the vegetation of India changes from one region to another. On the basis of certain common features such as predominant vegetation type and climatic regions, Indian forests can be divided into the following groups:

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

1.These forests are found in the western slope of the Western Ghats, hills of the northeastern region and the Andaman and Nicobar Islands.
2.They are found in warm and humid areas with an annual precipitation of over 200 cm and mean

3.Tropical evergreen forests are 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.
4. trees reach great heights up to 60 m or above.
5. There is no definite time for trees to shed their leaves, flowering and fruition. As such these forests appear green all the year round.
6.Species found in these forests include rosewood, mahogony, aini, ebony, etc.

SEMI EVERGREEN FOREST
1.The semi evergreen forests are found in the less rainy parts of these regions.
2.Such forests have a mixture of evergreen and moist deciduous trees.
3.The under growing climbers provide an evergreen character to these forests.
4.Main species are white cedar, hollock and kail.
5.The oak forests in Garhwal and Kumaon were replaced by pine (chirs) which was needed to lay railway lines.
6. Forests were also cleared for introducing plantations of tea, rubber and coffee.

Tropical Deciduous Forests

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

The Moist deciduous forests

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

Dry deciduous forest

1.covers vast areas of the country,

2. rainfall ranges between 70 -100 cm.
3.On the wetter margins, it has a transition to the moist deciduous, while on the drier margins to thorn forests.
4.These forests are found in rainier areas of the Peninsula and the plains of Uttar Pradesh and Bihar.
5.park lands are found In the higher rainfall regions of the Peninsular plateau and the northern Indian plain,
6.As 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. In the western and southern part of Rajasthan, vegetation cover is very scanty due to low rainfall and overgrazing.

Tropical Thorn Forests

1.Tropical thorn forests occur in the areas which receive rainfall less than 50 cm.

2.These consist of a variety of grasses and shrubs.
3.It includes semi-arid areas of south west Punjab,Haryana, Rajasthan, Gujarat, Madhya Pradesh and Uttar Pradesh.
4.In these forests, plants remain leafless for most part of the year and give an expression of scrub vegetation.
5.Important species found are babool, ber, and wild date palm, khair, neem, khejri, palas, etc.
6.Tussocky grass grows upto a height of 2 m as the under growth. 

Montane Forests

1.In mountainous areas, the decrease in temperature with increasing altitude leads to a corresponding change in natural vegetation.
2.Mountain forests can be classified into two types, the northern mountain forests and the southern mountain forests.
3.The Himalayan ranges show a succession of vegetation from the tropical to the tundra, which change in with the altitude.
4. Deciduous forests are found in the foothills of the Himalayas.
5. It is succeeded by the wet temperate type of forests between an altitude of 1,000-2,000 m.
6. In the higher hill ranges of northeastern India, hilly areas of West Bengal and Uttaranchal,
7. evergreen broad leaf trees such as oak and chestnut are predominant. Between 1,500-1,750 m, pine forests are also well-developed in this zone, with Chir Pine as a very useful commercial tree.
8. Deodar, a highly valued endemic species grows mainly in the western part of the Himalayan range. Deodar is a durable wood mainly used in construction activity.
9.Similarly, the chinar and the walnut, which sustain the famous Kashmir handicrafts, belong to this zone. Blue pine and spruce appear at altitudes of 2,225-3,048 m.
10.At many places in this zone, temperate grasslands are also found. But in the higher reaches there is a transition to Alpine forests and pastures.
11. Silver firs, junipers, pines, birch and rhododendrons, etc. occur between 3,000-4,000 m.
12.these pastures are used extensively for transhumance by tribes like the Gujjars, the Bakarwals, the Bhotiyas and the Gaddis.
13The southern slopes of the Himalayas carry a thicker vegetation cover because of relatively higher precipitation than the drier north-facing slopes. At higher altitudes, mosses and lichens form part of the tundra vegetation.

The southern mountain forests
1.Include the forests found in three distinct areas of Peninsular India viz; the Western Ghats, the Vindhyas and the Nilgiris.
2.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.
3.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.
4.Such forests are also found in the Satpura and the Maikal ranges.

• Littoral and Swamp Forests

1.India has a rich variety of wetland habitats.
2.About 70 per cent of this comprises areas under paddy cultivation.
3.The total area of wetland is 3.9 million hectares.
4.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;
(v) the floodplains of the Brahmaputra; the marshes and swamps in the hills of northeast India and the Himalayan foothills;
(vi) the lakes and rivers of the montane region of Kashmir and Ladakh; and
(vii) the mangrove forest and other wetlands of the island arcs of the Andaman and Nicobar Islands.
(viii)Mangroves grow along the coasts in the salt marshes, tidal creeks, mud flats and estuaries.

Mangrove Forests
1. the mangrove forests spread over 6,740 sq. km which is 7 per cent of the world‘s mangrove forests.
2. They are highly developed in the Andaman and Nicobar Islands and the Sunderbans of West Bengal.
3.Other areas of significance are the Mahanadi, the Godavari and the Krishna deltas.

FOREST COVER IN INDIA
1.According to state records, the forest area covers 23.28 per cent of the total land area of the country.
2.It is important to note that the forest area and the actual forest cover are not the same.
3.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.
4.The former is based on the records of the State Revenue Department, while the latter is based on aerial photographs and satellite imageries.
5.According to India State of Forest Report 2011,the actual forest cover in India is only 21.05 per cent.
6.Of the forest cover, the share of dense and open forests are 12.29 and 8.75 per cent respectively.
7.Both forest area and forest cover vary from state to state.
8.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.
On the basis of the percentage of the actual forest cover, the states have been grouped intofour regions:

The Region Percentage
Cover of the Forest
(i) The region of high concentration > 40
(ii) The region of medium concentration 20-40
(iii) The region of low concentration 10-20
(iv) The region of very low concentration < 10
Taking the data from Appendix IV, list the states under the four regions of forest cover

FOREST CONSERVATION
1.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;
(iv) increasing the forest cover through social forestry and afforestation on degraded land;
(v) increasing the productivity of forests to make timber, fuel, fodder and food available to rural population dependent 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.

Forests and Life Uses of forest
(i) To a vast number of tribal people, the forest is a home, a livelihood, their very existence.
(ii) It provides them food, fruits of all kinds, edible leaves, honey, nourishing roots and wild game.
(iii) It provides them with material to build their houses and items for practicing their arts.
(iv) The importance of forests in tribal economy is well-known as they are the source of sustenance and livelihood for tribal communities.
(v) It is commonly believed that the tribal communities live in harmony with nature and protect forests.
(vi) Out of a total of 593 districts 188 have been identified as tribal districts.
(vii)The tribal districts account for about 59.61 per cent of the total forest cover of the country whereas the geographical area of 188 tribal districts forms only 33.63 per cent of the total geographical area of the country.

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.
1.Urban forestry, 2.Rural forestry 3. Farm forestry.
Urban forestry pertains to the raising and management of trees on public and privately owned lands in and around urban centers 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.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
It is estimated that about 4-5 per cent of all known plant and animal species on the earth are found in India.
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 fuel wood 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.

The two main objectives of the Act are;
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.
3.This Act has been comprehensively 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.
4.There are 102 National parks and 515 wildlife sanctuaries covering an area of 15.67 million hectares in the country.
5.Wildlife conservation has a very large ambit with unbounded potential for the well-being of humankind. However, this can be achieved only when every individual understands its significance and contributes his bit.
6.For the purpose of effective conservation of flora and fauna, special steps have been initiated by the Government of India in collaboration with UNESCO‘s ‗Man and Biosphere Programme‘.
7.Special schemes like Project Tiger (1973) and Project Elephant (1992) have been launched to conserve these species and their habitat in a sustainable manner.
8.Project Tiger has been implemented since1973.

The main objective of the scheme is
1.To ensure maintenance of viable population of tigers in India for scientific, aesthetic, cultural and ecological values,
2.to preserve areas of biological importance as natural heritage for the benefit, education and enjoyment of the people.
3.the Project Tiger was launched in nine tiger reserves, covering an area of 16,339 sq. km, which has now increased to 27 tiger reserves, encompassing 37,761sq. km of tiger habitats distributed in 17 states.
4.The tiger population in the country has registered an increase from 1,411 in 2006 to 1,706 in 2010.
5.Project Elephant was launched in 1992 to assist states having free ranging population of wild elephants.
6.It was aimed at ensuring long term survival of identified viable population Of elephants in their natural habitat.
7.The project is being implemented in 13 states. Apart from this, some other projects such as Crocodile Breeding Project, Project Hangul and conservation of Himalayan Musk deer have also been launched by the Government of India.

BIOSPHERE RESERVES
A Biosphere Reserve is a unique and representative ecosystem of terrestrial and coastal areas which are internationally recognized within the framework of UNESCO‘s Man and Biosphere (MAB) Programme.
The Biosphere Reserve aims at achieving the three objectives as depicted.
There are 14 Biosphere Reserves in India
Figure 5.8 : Objectives of a Biosphere Reserve
Table 5.1 : List of Biosphere Reserves
1. * Nilgiri 2. * Nanda Devi 3. * Nokrek 5. * Sunderbans)7. Great Nicobar 8. * Similipal
9. Dibru-Saikhowa 10. Dihang Dibang 11. * Pachmarhi 12. Kanchenjunga 13. Agasthyamalai 14.
Achanakmar- 15. Kachchh 16. Cold Desert 17. Seshachalam 18. Panna
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

1.the first of the fourteen biosphere reserves of India,
2.established in September 1986.
3. 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.
4.The total area of the biosphere reserve is around 5,520 sq. km.
5.The Nilgiri Biosphere Reserve possesses different habitat types, un spoilt areas of natural vegetation types with several dry scrubs, dry and moist deciduous, semi evergreen and wet evergreen forests, evergreen sholas, grasslands and swamps.
6. It includes the largest known population of two endangered animal species, namely the Nilgiri Tahr and the Lion-tailed macaque.
7.The largest south Indian population of elephant, tiger, gaur, sambar and chital as well as a good number of endemic and endangered plants are also found in this reserve.
8.The habitat of a number of tribal groups remarkable for their traditional modes of harmonious use of the environment are also found here.
9.The average altitude of 250 m to 2,650 m.
10.About 80 per cent of the flowering plants reported from the Western Ghats occur in the Nilgiri Biosphere Reserve.

Nanda Devi Biosphere Reserve
1.The Nanda Devi Biosphere Reserve situated in Uttaranchal includes parts of Chamoli, Almora, Pithoragarh and Bageshwar districts.
2.The major forest types of the reserve are temperate.
3.A few important species are silver weed and orchids like latifolie and rhododendron.
4. 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.
5.Major threats to the ecosystem are the collection of endangered plants for medicinal use, forest fires and poaching.

Sunderbans Biosphere Reserve
1.It is located in the swampy delta of the river Ganga in West Bengal.
2.It extends over a vast area of 9,630 sq. km
3.consists of mangrove forests, swamps and forested islands.
4.Sunderbans is the home of nearly 200 Royal Bengal tigers.
5.The tangled mass of roots of mangrove trees provide safe homes for a large number of species,
6.from fish to shrimp. More than 170 birds species are known to inhabit these mangrove forests.
7.the tigers at the park are good swimmers, and they hunt scarce preys such as chital deer, barking deer, wild pig and even macaques.
8.In the Sunderbans, the mangrove forests are 148 characterized by Heritiera fomes, a species valued for its timber.

Gulf of Mannar Biosphere Reserve
1.The Gulf of Mannar Biosphere Reserve covers an area of 105,000 hectares on the southeast coast of India.
2.It is one of the world‘s richest regions from a marine biodiversity perspective.
3.The biosphere reserve comprises 21 islands with estuaries, beaches, forests of the near shore environment, sea grasses, coral reefs, salt marshes and mangroves.
4.Among the Gulf‘s 3,600 plant and animal species are the globally endangered e.g. sea cow (Dugongdugon).
5.Besides six mangrove species, endemic to Peninsular India are also endangered