NOTES OF CHAPTER-5 (NATURAL VEGETATION AND WILDLIFE) CLASS-9th Geography
Natural Vegetation And Wildlife Notes and Important Questions and Answers for Exams
India is a vast country having different types of bio-forms and is ranked the 12th mega bio-diversity country in the world. The country has many plant species, flowering plants, nonflowering plants, species of animals and a rich variety of fish in its fresh and marine waters.
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.
Virgin vegetation are of two types
- Endemic species Those plant species which originated from the country, are termed as endemic species.
- Exotic species Those plant species which originated outside the country are termed as exotic species.
The term flora is used to denote plants of a particular region or period. The species of animals are referred to as fauna. This huge diversity in flora and fauna kingdom is due to the following factors:
1) Relief
Land
Land affects natural vegetation directly and indirectly.
- The fertile level is generally devoted to agriculture.
- The undulating and rough terrains are areas where grassland and woodlands develop and give shelter to a variety of wildlife.
Soil
Different types of soils provide a basis for different types of vegetation.
- The sandy soils of the desert support cactus and thorny bushes, while wet, marshy, deltaic soils support mangroves and deltaic vegetation.
- The soil at the hill slopes has conical trees.
2) Climate
Temperature
The character and extent of vegetation are mainly determined by temperature along with humidity in the air, precipitation and soil. The fall in the temperature affects the vegetation and its growth.
Photoperiod (Sunlight)
The variation in the duration of sunlight at different places is due to differences in latitude, altitude, season and duration of the day. Due to the longer duration of sunlight, trees grow faster in summer.
Precipitation
Advancing South-West monsoon (June to September) and retreating North-East (October- November) monsoons bring almost all the rainfall in India. Areas of heavy rainfall always have denser vegetation than other areas with lesser rainfall. The South-West monsoon rains on the windward side of the Western Ghats, thus cause a heavy growth of tropical evergreen forests there, whereas the leeward side does not have any such forests.
Ecosystem
Various species of plants occur in areas having similar climatic conditions. To a large extent its nature determines the animal life in that area. All the plants and animals in an area are interdependent on each other in their physical environment and form an ecosystem. Thus, an ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the non-living, physical components of the environment with which the organisms interact, such as air, soil, water and sunlight.
Biome
It is a major community of plants and animals having similar life forms existing under similar environmental conditions. A biome is identified on the basis of plant existing there. It is also termed as ‘major life zone’.
Importance of Forests
Forests are advantageous for the environment. They influence climate, reduce soil erosion, regulate stream flow, provide raw material for industries and livelihood for many, etc. They control wind force and temperature and cause rainfall. They also provide shelter to various animal species.
Types of Vegetation
In India, the following major types of vegetation are found:
- Tropical Evergreen Forests
- Tropical Deciduous Forests
- Tropical Thorn Forests and Scrubs
- Montane Forests
- Mangrove Forests
Let’s study them in detail.
Tropical Evergreen Forests
These forests are present in the Western Ghats and the island groups of Lakshadweep, Andaman and Nicobar, upper parts of Assam and Tamil Nadu coast.
- These forests grow best in areas having rainfall more than 200 cm with a short dry season.
- The trees reach great heights up to 60 metres or even above.
- It has the vegetation of all kinds i.e trees, shrubs and creepers giving it a multilayered structure.
- These forests appear green all the year-round.
- Important trees of this forest are ebony, mahogany, rosewood, rubber and cinchona.
- Common animals found in these forests are elephant, monkey, lemur and deer.
Tropical Deciduous Forests
These forests are also called monsoon forests.
- They are spread over the region having rainfall between 200 cm and 70 cm.
- They shed their leaves about 6 to 8 weeks in the dry summer.
- In these forests, the common animals found are lion, tiger, pig, deer and elephant.
These forests are further divided into:
- Moist deciduous: These are found in areas having rainfall between 200 and 100 cm. Teak is the most dominant species of this forest. Bamboos, sal, shisham, sandalwood, khair, kusum, arjun and mulberry are other commercially important species.
- Dry deciduous: These are found in areas having rainfall between 100 cm and 70 cm. There are open stretches, in which teak, sal, peepal and neem grow.
The Thorn Forests and Scrubs
The natural vegetation consists of thorny trees and bushes. 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.
- Trees are scattered and have long roots penetrating deep into the soil to get moisture.
- The stems are moist to conserve water.
- Leaves are mostly thick and small to minimise evaporation.
- Acacias, palms, euphorbias and cacti are the main plant species.
- Common animals are rats, mice, rabbits, fox, wolf, tiger, lion, wild ass, horses and camels.
Montane Forests
Montane forests are the forests which are found in the mountains.
- The wet temperate type of forests are found between a height of 1000 and 2000 metres.
- At high altitudes, generally, more than 3,600 metres above the sea level, temperate forests and grasslands give way to the Alpine vegetation.
- Alpine grasslands are used for grazing.
- At higher altitudes, mosses and lichens form part of tundra vegetation.
- The common animals found are Kashmir stag, spotted deer, wild sheep, jack rabbit, Tibetan antelope, yak, snow leopard, squirrels, shaggy horn wild ibex, bear and rare red panda, sheep and goats.
Mangrove Forests
Mangroves are trees that live along tropical coastlines, rooted in salty sediments, often underwater.
- The mangrove tidal forests are found in the areas of coasts influenced by tides. Mud and silt get accumulated on such coasts.
- Dense mangroves are the common varieties with roots of the plants submerged underwater.
- Sundari trees are found in Ganga-Brahmaputra delta and provide hard timber.
- Royal Bengal Tiger is a famous animal in these forests.
Wildlife
India is also rich in its fauna (animal life) same as in flora (plant life). It has approximately 90,000 animal species and 2,000 species of birds.
They constitute 13% of the total world’s stock. There are 2,546 species of fish, which account for nearly 12% of the world’s stock.
It also shares between 5 and 8 % of the world’s amphibians, reptiles and mammals. The existence of animals in our country varies place to place.
Distribution of Wildlife in India
- Elephants are found in the hot wet forests of Assam, Karnataka and Kerala.
- One-horned rhinoceroses are found in Assam and West Bengal.
- Rann of Kachchh is the habitat for wild ass whereas the Thar Desert is the habitat for camels.
- The natural habitat of the Indian lion is the Gir forest in Gujarat.
- Tigers are found in the forests of Madhya Pradesh, the Sundarbans of West Bengal and the Himalayan region.
- Ladakh’s freezing high altitudes are home to yak, the shaggy horned wild ox, the Tibetan antelope, the bharal (blue sheep), wild sheep, and the kiang (Tibetan wild ass).
- In the rivers, lakes and coastal areas, turtles, crocodiles and gharials are found.
- Peacocks, pheasants, ducks, parakeets, cranes and pigeons are some of the birds inhabiting the forests and wetlands of the country.
Migratory Birds
Some of the wetlands of India are popular with migratory birds. During winter, birds such as Siberian crane come in large numbers. One such place favorable with birds is the Rann of Kutch. At a place where the desert merges with the sea, flamingo with their brilliant pink plumage, come in thousands to build nest mounds from the salty mud and raise their young ones. It is one among many extraordinary sights in the country.
Cause of Major Threat to flora and fauna
Every species has an important role in the ecosystem. Hence, conservation of flora and fauna is essential. About 1,300 plant species are endangered and 20 species are extinct. The main causes of this major threat to nature are:
- Hunting for commercial purposes
- Pollution due to chemical and industrial waste
- Rapidly cutting of the forests for cultivation and habitation
Government Initiative to Protect Flora and Fauna
The government has taken many steps to protect the flora and fauna of our country.
- 18 biosphere reserves have been set up in India to protect flora and fauna. 10 out of these have been included in the world network of biosphere reserves.
- Financial and technical assistance has been provided to many botanical gardens by the government since 1992.
- Project Tiger, Project Rhino, Project Great Indian Bustard and many other eco-developmental projects have been introduced by the government.
- 103 National Parks, 535 Wildlife Sanctuaries and Zoological gardens are set up to take care of natural heritage.
Which factors determine the distribution of plants and animals in India?
Ans: Factors that determine natural vegetation and wildlife in a specific area are:
- Land: Land affects natural vegetation to a large extent. Fertile land is used for agricultural activities, while rough land is where grassland and woodland are found. According to land type varies the wildlife of a specific area.
- Soil: Soil varies over various regions, and along with that varies the natural vegetation. Sandy soil in the desert is perfect for cactus and thorny bushes, while wet marshy soils of the delta region support mangroves. Mountain slopes have soil with depth. These are perfect for the growth of conifer trees.
- Temperature: Temperature is another critical factor affecting the natural vegetation of a particular area like the Himalayas and the peninsular region. With changing temperatures, vegetation changes from tropical to subtropical temperate and alpine.
- Photoperiodism: The duration of sunlight received by an area is another factor that determines the vegetation in an area.
- Precipitation: The extent and density of natural vegetation cover in India areas of heavy rainfall are denser than sites that receive less rainfall. In India, the prime source of rain is the advancing south-westerly monsoons and the retreating monsoons.
Important Questions/Answers Regarding Examinations :-
1.Why is it essential to conserve natural vegetation and wildlife?
Ans: Natural vegetation and wildlife are considered as natural wealth of the country. This is because they are indispensable to us. We extract numerous benefits from these natural sources. For example, plants provide us with food, timber, etc. Medicinal plant extracts give us medicines. Animals provide transportation, meat, and eggs. Fish is an exceptionally nutritious food item and is exported to earn foreign revenues. Insects help in pollination and fruit and crop formation. The ecosystem, as a whole, is essential and contributes to our sustenance.
2.Why are a few species of animals and plants endangered in India?
Ans: Few animal and plant species are endangered in India, while some have become extinct. Human activities have been a significant threat to nature. Hunting by greedy hunters and poachers, pollution due to anthropogenic activities, the introduction of alien species in a natural ecosystem, indiscriminate cutting down of forests for cultivation, habitation, and grazing have created an imbalance in nature, and natural ecosystems have been disturbed.
3.Write a short note on migratory birds.
Ans: Migratory birds are those which travel from the polar regions during the winters to warmer places. The wetlands of India are famous for harbouring such migratory birds. During the winters, Siberian cranes visit the country in large numbers. The Rann of Kutch is one such place where you can spot these migratory birds. Here the desert merges with the sea, and pink flamingo plummets come in considerable numbers to build nests from the salty mud. It is a brilliant sight to behold at. The Keoladeo National park in Bharatpur, Rajasthan, is famous for harbouring migratory birds.
4.Why does India have rich flora and fauna?
Ans: India is a diverse country. There is a striking diversity of land reliefs, soil types, temperature ranges, humidity, and precipitation all across India. Even the monsoon season varies across the grids. Each place in India has a unique combination of factors that determine the growth of natural vegetation in a particular place. These critical factors which influence flora and fauna vary widely from South to North and East to West. Hence India has rich flora and fauna which are suited to grow in various regions. The position of India in both the Tropical and the temperate zone is also an important reason for the existence of such a plethora of fauna and flora in the country.
5.What is a biosphere reserve? Name the biosphere reserves in India.
Ans: The biosphere can be defined as an ecosystem consisting of naturally growing plants and animals of a specific region of unusual scientific and natural interest. UNESCO gives a place the label of a biosphere reserve. It is an entity for sustainable development. Biosphere reserves include terrestrial and coastal ecosystems. The biosphere reserves in India are Sundarban, Shimlipal, Gulf of Mannar. Dihang-Dibang, Nilgiri, Dibru Saikhowa, Nanda Devi, Agasthyamalai, Great Nicobar, Panchmari, and AchanakmarAmarkantak.
6.What are the natural vegetation and wildlife conservation strategies taken up by the government of India?
Ans: The Government of India has taken a few steps to conserve natural vegetation and wildlife. These are:
- 18 Biosphere Reserves were set up in the country. Out of which, ten of them are among the world network of biosphere reserves.
- Financial assistance and technical aid have been provided to botanical gardens since 1992.
- Ecological development projects such as Project Tiger, Project Rhino, and the Indian Bustard have been established to save these endangered species.
- 535 wildlife sanctuaries and 103 national parks were set up in the country, along with many zoological gardens to conserve the natural heritage.
7.Name some medicinal plants found in India along with their usage.
Ans: India is famous for herbs and spices. Indian Ayurveda uses 2000 species of Ayurvedic plants, out of which 500 are regularly used. Some of the medicinal plants of India are-
- Jamun – Jamun is used to prepare vinegar. It is carminative, and a diuretic and has excellent digestive properties. Jamun seed powder is used for diabetes treatment.
- Arjun – It is known to have properties to control headache and earache. It is used for diabetes treatment.
- Neem – Neem is known to possess antimicrobial properties.
- Tulsi – Tulsi is used to cure a cold and cough.
- Babul – Babul is known to be a gum tonic. It is also used for fixing eyesores.
- Sarpagandha – This plant is only found in India and is used to treat blood pressure.
- Kachnar is excellent for curing asthma and ulcers, and also its buds and roots have excellent digestive properties.
8.Distinguish between Tropical Evergreen and Deciduous forests
Answer:
Tropical Evergreen Forests:
- They are called rain forest.
- No definite time for trees to shed leaves.
- Rainfall is more than 200 cm.
- Ebony, Mahogany, Rosewood, rubber, and Cinchona are important trees of these forests.
- Common animals found in these forests are elephants, monkeys, lemur, deer, etc
Tropical Deciduous Forests:
- They are called Monsoon forest.
- Trees shed leaves for about six to eight weeks in the dry summer.
- Rainfall range is between 200 cm to 70 cm.
- Teak, Bamboo, Sal, Shisham, Sandalwood, Peepal, Neem are important trees of these forests.
- Common animals found in these forests are lion, tiger, deer, elephant, etc