- 1 Introduction
- 2 Natural Vegetation
- 3 Factors Affecting Diversity in Flora and Fauna
- 4 Types of Vegetation
- 5 Tropical Evergreen Forests
- 6 Tropical Deciduous Forests
- 7 The Thorn Forests and Scrubs
- 8 Mountain Forests
- 9 Mangrove Forests
- 10 Wildlife
- 11 Conservation/Protection of Flora and Fauna
- 12 Migratory Birds
(i) India is one of the 12 mega biodiversity countries in the world.
(ii) With about 47,000 plant species, India occupies 10th place in the world and fourth in Asia in plant diversity.
(iii) There are about 15,000 flowering plants in India which account for 6% of the world’s total number of flowering plants. The country has many non-flowering plants such as ferns, algae and fungi.
(iv) India also has 89,000 species of animals as well as a rich variety of fish in the fresh and marine waters.
(i) Natural vegetation refers to a plant community which has grown naturally without human aid and has been left undisturbed by humans for a long time. This is termed as virgin vegetation.
(ii) Thus, cultivated crops and fruits orchards form part of vegetation but not natural vegetation.
(iii) The virgin vegetation which is purely Indian is known as endemic or indigenous species, but those which have come from outside India are termed as exotic plants.
(iv) The term flora is used to denote plants of a particular region or period. Similarly, the species of animals are referred to as fauna. This huge diversity in flora and fauna kingdom is due to the factors given below.
Factors Affecting Diversity in Flora and Fauna
(1) Land affects the natural vegetation directly and indirectly.
(2) Fertile land is generally devoted to agriculture and the rough terrain areas where grasslands and woodlands develop give shelter to a variety of wildlife.
(1) Soils also vary over space. Different types of soils support different types of vegetation.
(2) The sandy soils of the desert support cactus and thorny bushes, while wet marshy and deltaic soil supports mangroves and deltaic vegetation. The hill slopes with some depth of soil have conical trees.
(1) The character and extent of vegetation are mainly determined by temperature and soil.
(2) On the slopes of the Himalayas and the hills of the peninsula above the height of 915 metres the fall in temperature affects, the types of vegetation and its growth, and changes it from tropical to subtropical temperate and alpine vegetation.
(b) Photoperiod (Sunlight)
(1) The variation of sunlight at different places is due to difference in latitude and altitude, season and duration of the day.
(2) Due to longer duration of sunlight trees grow faster in summer.
(1) In India almost the entire rainfall is brought in by the advancing monsoon (June to September) and retreating monsoons.
(2) Areas of heavy rainfall have more dense vegetation as compared to other areas of less rainfall.
(3) Forests are renewable resources and play a major role in enhancing the quality of environment.
(4) Forests modify local climate, control soil erosion, regulate stream flow, support a variety of industries, provide livelihood for many communities and offer panoramic or scenic view for recreation.
(5) Forests control wind force and cause rainfall.
(6) They provide humus to the soil and shelter to wild life.
(7) Except in some inaccessible regions like the Himalayas, the hilly region of central India and the desert areas, the vegetation of most areas has been modified at some places, or replaced or degraded by human occupancy.
(a) All the plants and animals in an area are interdependent and interrelated to each other in their physical environment, thus forming an ecosystem.
(b) Human beings are also an integral part of the ecosystem. They utilise the vegetation and wild life.
(c) The greed of human beings leads to over utilisation of these resources. They cut the trees and kill the animals, creating an ecological imbalance. As a result, some plants and animals have reached the verge of extinction.
(d) A very large ecosystem on land having distinct types of vegetation and animal life is called a biome. The biomes are identified on the basis of plants.
Types of Vegetation
The following types of vegetation are found in India.
(i) Tropical Evergreen Forests
(ii) Tropical Deciduous Forests
(iii) Tropical Thorn Forests and Scrub
(iv) Montane Forests
(v) Mangrove Forests
Tropical Evergreen Forests
(i) These forests are found in heavy rainfall (200 cm) areas of the Western Ghats and the island groups of Lakshadweep, Andaman and Nicobar, upper parts of Assam and TamilNadu coast.
(ii) The trees reach great heights upto 60 metres, or even above.
(iii) Since the region is warm and wet throughout the year, it has luxuriant vegetation of all kinds, trees, shrubs and creepers, giving it a multi layered structure.
(iv) There is no definite time for the tress to shed their leaves as such these forests appear green all the year round.
(v) Some of the commercially important trees of this forest are ebony, mahogany, rosewood, rubber and cinchona.
(vi) The common animals found in these parts are elephants, monkey, lemur and deer. The one horned rhinoceros are found in the jungles of Assam and West Bengal.
(vii) Plenty of birds, bats, sloths, scorpions and snails are also found in these jungles.
Tropical Deciduous Forests
(i) They are the most widespread forests of India.
(ii) They are also called the monsoon forests and spread over the region receiving rainfall between 200 cm and 70 cm.
(iii) Trees of this forest type shed their leaves for about 6 to 8 weeks in dry summer.
(iv) On the basis of availability of water, these forests are further divided into moist and dry deciduous.
(v) The moist deciduous are found in areas receiving rainfall between 200 and 100 cm.
(vi) These forests exist mainly in the eastern part of the country, north eastern states, Jharkhand, Orissa and Chhattisgarh and on the eastern slopes of the Western Ghats.
(vii) Teak is the most dominant species of this forest, Bamboos, Sal, Shisham , Sandalwood, Khair Kusum, Arjun, Mulberry are other commercially important trees.
(viii) The dry deciduous forests are found in areas having rainfall between 100 cm and 70 cm.
(ix) The dry deciduous forests are found in the rainier parts of the peninsular plateau and the plains of Bihar and Uttar Pradesh.
(x) Teak, Sal, Peepal and Neem are the important trees.
(xi) A large part of this region has been cleared for cultivation and some parts are used for grazing.
(xii) The common animals found are lion, tiger, pig, deer and elephant.
(xiii) A huge variety of birds, lizards, snakes and tortoises are also found here.
The Thorn Forests and Scrubs
(i) This type of forests and vegetation are found in regions with less than 70 cm of rainfall.
(ii) This type of vegetation is found in the north-western part of the country including semi-arid areas of Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Uttar Pradesh and Haryana.
(iii) Acacias, palms, euphorbias and cacti are the main plant species. Trees are scattered and have long roots penetrating deep into the soil in order to get moisture. The leaves are mostly thick and small to minimise evaporation.
(iv) These forests give way to thorn forests and scrubs in arid areas.
(i) The montane forests in India are found in the Himalayas.
(ii) The wet temperate type of forests are found between a height of 1,000 and 2,000 metres.
(iii) Evergreen broad leaf trees such as oaks and chestnuts predominate.
(iv) Between 1500 and 3,000 metres height, temperate forests containing coniferous trees like pine, deodar, silver fir, spruce and cedar are found.
(v) These forests cover mostly the southern slopes of the Himalayas and places having high altitudes in southern and north-east India.
(vi) At higher elevations, temperate grasslands are common.
(vii) At high altitudes, generally more than 3,600 metres above sea level, temperate forests and grasslands give way to the Alpine vegetation. Silver fir, jumpers, pines and birches are the common trees of these forests.
(viii) The common animals found in these forests are Kashmir stag, spotted deer, wild sheep, jack rabbit, Tibetan antelope, yak, snow leopard, squirrels, shaggy horn wild ibex, bear, red panda, sheep and goats with thick hair.
(i) Mangrove tidal forests are found in the areas of coasts influenced by tides.
(ii) Mud and silt get accumulated on such coasts.
(iii) Dense mangroves are the common varieties with roots of the plants submerged under water.
(iv) The deltas of the Ganga, Mahanadi, Krishna, Godavari and Kaveri are covered by such vegetation.
(v) In the Ganga- Brahmaputra delta, Sundari trees are found, which provide durable hard timber. Palm coconut, keora and agar also grow in some parts of the delta.
(vi) Royal Bengal Tiger is the famous animal in these forests.Turtles, crocodiles, gharials and snakes are also found in these forests.
(i) Like its flora, India is also rich in its fauna.
(ii) It has more than 89,000 animal species.
(iii) The country has more than 1,200 species of birds.
(vi) They constitute 13% of the world’s total species.
(v) There are 2,500 species of fish which account for nearly 12% of the world’s species.
(vi) It also has between 5 and 8% of the world’s amphibians, reptile and mammals.
(vii) The elephants are the most majestic animals among the mammals. They are found in the hot wet forests of Assam and West Bengal.
(viii) Arid areas of the Rann of Kachchh and the Thar desert are the habitat for wild ass and camels respectively.
(ix) Indian bison, nilgai (blue bull), chousingha (four horned antelope), gazelle and different species of deer are also found in India.
(x) It also has several species of monkeys.
(xi) India is the only country in the world that has both tigers and lions.
(xii) The natural habitat of the Indian lion is the Gir forest in Gujarat.
(xiii) Tigers are found in the forests of Madhya Pradesh, the Sundarbans of West Bengal and the Himalayan region.
(xiv) Leopards too are members of the cat family.
(xv) Ladakh is home to the yak, the Tibetan antelope, the Bharal (blue sheep), wild sheep and the Kiang (Tibetan wild ass). The ibex, bear, snow-leopard and the very rare panda are also found in certain areas.
(xvi) In the rivers, lakes and coastal areas, turtles, crocodiles and gharials are found.
(xvii) Birds like peacocks, pheasants, ducks, parakeets, cranes and pigeons are found in the forests and the wetlands of the country.
(xviii) Animals provide us draught power, transportation, meat, eggs and milk.
(xix) Insects help in pollination of crops and fruits.
(xx) Every species plays a role in the eco-system.
(xxi) Due to excessive exploitation of plant and animal resources by human beings, the eco-system has been disturbed.
(xxii) The main causes for the major threat to nature are hunting by greedy hunters for commercial interests.
(xxiii) Pollution due chemical and industrial waste, introduction of alien species and reckless cutting of the forests to bring land under cultivation and inhabitation are also responsible for the imbalance.
Conservation/Protection of Flora and Fauna
(i) The government has taken many steps to protect the flora and fauna.
(a) Fourteen biosphere reserves have been set up in the country to protect flora and fauna.
Sundarbans in West Bengal, Nanda Devi in Uttaranchal, the Gulf of Mannar in Tamil Nadu and the Nilgiris (hills situated in the states of Kerala, Karnataka and Tamil Nadu) have been included in the world network of biosphere reserves.
(b) Financial and technical assistance is provided to many botanical gardens by the government since 1992.
(c) Project Tiger, Project Rhino, Project Great Indian Bustard and many other eco-developmental projects have been introduced.
(d) 89 National Parks, 49 Wildlife Sanctuaries and zoological gardens are set up to take care of our natural heritage.
Some of the wet lands of India are popular with migratory birds. During winter, birds such as Siberian Crane come in large numbers. One such place favourable with birds is the Rann of Kachchh. Flamingoes with their brilliant, pink plumage come in thousands to build nest mounds from the salty mud and raise their young ones.
The Fourteen Bio-reserves are
(ii) Gulf of Mannar
(iii) The Nilgiris
(vi) Dibru Saikhowa
(xi) Nanda Devi
(xiii) Great Nicobar