Natural Vegetation And Wildlife Class 9 Notes Geography - Chapter 5

Chapter: 5

India is one of the 12 mega bio-diversity countries of the world. With about 47,000 plant species and approximately 90,000 species of animals, as well as, 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 a virgin vegetation.
The term flora is used to denote plants of a particular region or period. Similarly, the species of animals are referred to as fauna.
Three factors of biodiversity: Relief, Climate and Eco-system.

Relief

Climate

Eco-System

All the plants and animal in an area are independent and interrelated to each other in their physical environment, thus, forming an ecosystem.

Plays an important role in modifying climate and weather.

Increases the precipitation of any area and controls humidity.

Plays important role in erosion control and in reducing floods.

Controls major pollution such as water,air, and noise pollution.

Acts as source of food and shelter for many wild animals.

Tropical Evergreen Forests: Receives heavy rainfall; trees reach up to a height of 60m or above and has luxuriant vegetation of all kind.

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. On the basis of the availability of water, these forests are further divided into moist and dry deciduous.

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.

Montane Forests: In mountainous areas, the decrease in temperature with increasing altitude leads to the corresponding change in natural vegetation. As such, there is a succession of natural vegetation belts in the same order as we see from the tropical to the tundra region.

Mangrove Forests: 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 under water.

The country has around 2,000 species of birds. They constitute 12% of the world’s total species of birds.

There are around 2,546 species of fish, which account for nearly 12% of the world’s stock. It also shares between 5 and 8 per cent of the world’s amphibians, reptiles and mammals.