Class 9 Geography


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 Affecting 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.