Natural Vegetation
and Wildlife
Natural Vegetation: The naturally growing plant cover without human aid is called natural vegetation. The vegetation which has been left undisturbed by humans for a long time is called virgin vegetation.
Flora: Plant species of a particular region or period are called flora.
Fauna: The animal species of a particular region or period are called fauna.
Factors which affect the diversity of flora and fauna:
RELIEF
Land: Land directly and indirectly affects the natural vegetation. Nature of land influences the type of vegetation. If the land is level and fertile, it is mainly used for farming. If the land is uneven then grassland and woodlands develop over it.
Soil: Different types of soil are fit for different types of vegetation. For example; sandy soil is fit for cactus and thorny bushes, while wet and marshy soil is fit for mangrove vegetation.
CLIMATE
Temperature and Humidity: Temperature and humidity are the main factors which determine the character and extent of vegetation. An area with high temperature and high humidity supports evergreen forest, while an area with high temperature and low humidity supports thorny bushes.
Photoperiod (Sunlight): The duration of sunlight is called photoperiod. Photoperiod depends on latitude, altitude, season and duration of the day. Trees grow faster in summer because of longer photoperiod.
Precipitation: If an area gets heavy rainfall, it is suitable for the growth of dense vegetation. On the other hand, an area with scanty rainfall is suitable for thorny bushes.
Ecosystem: All the plants and animals in an area are interdependent on each other. The plants and animals; alongwith their physical environment make the ecosystem. A very large ecosystem is called a biome. Biomes are identified on the basis of plants.
TYPES OF VEGETATION
There are five major types of vegetation in India: Tropical Rainforests, Tropical Deciduous Forests, Tropical Thorn Forests and Scrubs, Montane Forests and Mangrove Forests.
Tropical Rain Forests
- The tropical rainforests are confined to areas of heavy rainfall. Such areas are in the Western Ghats, upper parts of Assam, Tamil Nadu coast and the island groups of Lakshadweep and Andaman & Nicobar.
- Areas which receive more 200 cm of rainfall and have a short dry season are the best area for tropical rainforest. Almost all kinds of vegetation; like trees, shrubs and creepers; are found in such a forest. The forest has a multilayered structure.
- Ebony, mahogany, rosewood, rubber and cinchona are some of the commercially important trees of tropical rainforests.
- Elephants, monkey, lemur and deer are the common animals in these forests. Apart from them, a large number of birds, bats, sloth, scorpions and snails are also found in tropical rainforests.
Tropical Deciduous Forests
Tropical deciduous forests are the most widespread forests of India. They are spread in those regions which get rainfall between 200 cm and 70 cm. They are also called the monsoon forests. The trees of tropical deciduous rainforests shed their leaves during summer.
These forests can be divided into two types on the basis of availability of water.
- Moist Deciduous Forest: The moist deciduous forests are found in areas which receive rainfall between 200 cm and 100 cm. Such forests are found mainly in the eastern part of India; like northeastern states, along the foothills of the Himalayas, Jharkhand, West Orissa and Chhattisgarh. They are also found on the eastern slopes of the Western Ghats.
- Dry Deciduous Forest: The dry deciduous forests are found in those regions which receive rainfall between 100 cm and 70 cm. Such forests are found in the rainier parts of the peninsular plateau and the plains of Bihar and Uttar Pradesh.
Teak, bamboo, sal, shisham, sandalwood, khair, kusum, arjun, mulberry are some of the commercially important trees in these forests. Lion, tiger, pig, deer and elephant are the common animals in these forests. Additionally, a large variety of birds, lizards, snakes and tortoises are found in these forests.