NCERT Notes for Class 9 Social Science Geography Chapter 5 Natural Vegetation and Wildlife
Chapter 5 Natural Vegetation and Wildlife NCERT Notes
Chapter Name | Natural Vegetation and Wildlife Notes |
Class | CBSE Class 9 |
Textbook Name | Contemporary India- I Class 9 |
Related Readings |
|
Natural Vegetation
- Natural vegetation refers to a plant community which has grown naturally without human intervention for a long time.
- Natural vegetation is also termed as "Virgin Vegetation."
Types of Virgin Vegetation
On the basis of its residence it is of two types :
- Endemic: which are purely native.
- Exotic: which are brought from some other place long ago.
Flora
The term Flora is used to denote plants of a particular region or period.Fauna
Species of animals are referred as Fauna.Factors affecting Flora and fauna of a place:
- Land
- Soil
- Temperature
- Sunlight
- Precipitation
1. Land
- Nature of land influences type of vegetation as the undulating and rough terrains developed into a variety of natural wildlife as compared to fertile land which undergoes agricultural work.
2. Soil
- Different types of soil support different vegetation. Eg. sandy soil supports thorny bushes where as deltaic soil support mangrove vegetation.
3. Temperature
- As we can see that tropical area has variety of vegetation as Moreover as we go to the higher altitude, compared to temperate region. Vegetation cover changes from temperate forest to grassland to tundra and finally alpine type.
4. Sunlight
- It is observed that due to longer duration of sunlight trees grows faster in summer as compared to other season of year.
5. Precipitation
- Heavy rainfall areas have generally dense vegetation cover as compared to scanty rainfall areas.
Ecosystem
- The system of interaction among biotic component and their interaction with abiotic component of a particular area is called Ecosystem.
- Pond ecosystem, river ecosystem, lake, forest, grassland etc.
Biome
A very large ecosystem of an area having distinct types of flora and fauna is called Biome.Importance of Forests
Forests are advantageous for the environment.
- Help bring rain
- Oxygen supply
- They influence climate,
- Reduce soil erosion,
- Regulate stream flow,
- Provide raw material for industries ,
- Livelihood for many, etc.
India’s Natural Vegetation
- Our country India is one of the 12 mega bio-diversity countries of the world.
- With about 47,000 plant species India occupies tenth place in the world and fourth in Asia in plant diversity.
- There are about 15,000 flowering plants in India, which account for 6 per cent in the world’s total number of flowering plants.
- The country has many non- flowering plants, such as ferns, algae and fungi.
- India also has approximately 90,000 species of animals, as well as, a rich variety of fish in its fresh and marine waters.
Types of Vegetation
The following major types of vegetation may be identified in our country :-- Tropical Evergreen Forests
- Tropical Deciduous Forests
- Tropical Thorn Forests and Scrubs
- Montane Forests
- Mangrove Forests
1. Tropical Evergreen Forests
- These forests are restricted to heavy rainfall areas of the Western Ghats and the island sbe groups of Lakshadweep. Andaman and Nicobar, upper parts of Assam and Tamil Nadu coast.
- They are at their best in areas having more than 200 cm of rainfall with a short dry season. The trees reach great heights up to 60 metres or even above.
- Since the region is warm and wet throughout the year, it has a luxuriant vegetation of all kinds – trees, shrubs and creepers giving it a multilayered structure. There is no definite time for trees to shed their leaves. As such, these forests appear green all the year round.
Important tree species are Ebony, mahogany, rosewood, rubber and cinchona.
The common animals found in these forests are Elephant, monkey, lemur and deer.
2. Tropical Deciduous Forests
- These are the most widespread forests of India. They are also called the monsoon forests and spread over the region receiving rainfall between 200 cm and 70 cm. Trees of this forest type shed their leaves for about six to eight weeks in dry summer.
These forests are divided into two parts:
- Moist Deciduous Forests
- Dry Deciduous Forests
Moist Deciduous Forests
- The former is found in areas receiving rainfall between 200 and 100 cm. These forests exist, therefore, mostly in the eastern part of the country states, along the foothills of the Himalayas, Jharkhand, West Odisha and Chhattisgarh, and on the eastern slopes of the Western Ghats.
Important tree species
- Northeastern 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 Forests :-
- The dry deciduous forests are found in areas having rainfall between 100 cm and 70 cm. These forests are found in the rainier parts of the Peninsular plateau and the plains of Bihar and Uttar Pradesh.
Important tree species
- Teak, sal, peepal and neem grow.
The common animals found in these forests
- In these forests, the common animals found are lion, tiger, pig, deer and elephant. A huge variety of birds, lizards, snakes and tortoises are also found here.
3. Tropical Thorn Forests and Scrubs
- In regions with less than 70 cm of rainfall, 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 in order to get moisture.
- The stems are succulent to conserve water.
- Leaves are mostly thick and small to minimise evaporation.
Important tree species
- Acacias, palms, euphorbias and cacti are the main plant species.
The common animals found in these forests are
- Rats, mice, rabbits, fox, wolf, tiger, lion, wild ass, horses and camels.
4. 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.
Important tree species
- Silver fir, junipers, pines and birches.
The common animals found in these forests are
- Kashmir stag, spotted dear, wild sheep, jack rabbit, Tibetan antelope, yak, snow leopard, squirrels, Shaggy horn wild ibex, bear and rare red panda, sheep and goats with thick hair.
5. 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
- The country has around 90,000 animal species, 2000 species of bird, 2,546 species of fishes and 5-8% of world’s amphibians, reptiles and mammals.
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.
Danger to wildlife
- 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.
Steps taken to protect flora and fauna
- To protect the flora and fauna the government has taken followings steps :
- Wildlife Protection Act was implemented in 1972 in India.
- Fourteen biosphere reserves have been set up in the country to protect flora and fauna.
- Financial and technical assistance is 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.
- 89 National Parks, 490 Wildlife sanctuaries and Zoological gardens are set up to take care of Natural habitat of the fauna.