Our Revision Notes for GSEB Class 9 Social Science Notes Chapter 17 Natural Vegetation summarises the key points of a chapter and useful resource to prepare effectively for the upcoming board exams.
Natural Vegetation Class 9 GSEB Notes Social Science Chapter 17
Natural Vegetation Class 9 GSEB Notes
→ There are about 5000 varieties of trees in India, out of which 450 trees are useful commercially.
→Besides, about 15,000 flowering plants also grow which form about 6% of the world.
→Non-flowering plants like fem, algae, moss etc. are also available in our country.
→ India is famous since ancient times for the herbal plants.
→ About 2000 medicinal plants are described in Ayurved.
Type of Natural Vegetation
The natural vegetation regions can be divided into five types :
(1) Tropical Rain Forest
- Tropical Rain Forests are found in hot and humid regions where anuual rainfall exceeds 200 cm and temperature is more than 22° C.
- Trees found here are Mahogany, Ebony, Rosewood, rubber etc.
- Trees are about 60 metres tall or even more.
(2) Tropical Deciduous Forests :
- These forests are found in the regions receiving about 70 to 200 cm rainfall.
- Major trees found here are teak, saal, sesame, sandalwood, kher (acacia catechu) bamboo etc.
- The trees shed their leaves for 6 to 8 weeks during autumn. Every species has a different time to shed the leaves.
(3) Tropical Desert Vegetation
- These forests are found in the regions less than 70 cm of rainfall.
- Dates, jujube, acacia, cactus, khijdo etc. are common trees found here.
- The roots of the trees and plants here are long, deep and widespread.
- Leaves are shorter which result in slower evaportranspiration process.
(4) Temperate Forests and Grasslands (Flimalayan Vegetation)
- These forest also called as coniferous forests. These are found at activities between 1000 metres to 3600 meters and above in Flimalayas.
- There are tropical forests, coniferous forests, alpine and short grase (tundra vegetation) seen here.
- A major characteristic of the coniferous forests is that the trees have conical shape.
- Their branches lean towards the surface so that the snow would easily slide down towards the land.
(5) Tidal Forests (Mangroves)
- Tidal forests are located in the delta regions of river along the coast.
- These forests are found along Gujarat coast and in the marshy lands along the Bay of Bengal coast.
- Sundari and cher types of trees are seen.
Forest products and their utility
- Timber wood from teak and saal is used for furniture making.
- Boats are prepared from the wood of sundari trees of Sundarvan.
- Sports goods and packing boxes are prepared from the wood of pine and child trees.
- Ecosystem is formed due to the interrelation of biosphere and mankind.
- Due to the anti-environmental’ activities and selfishness of man, the ecosystem is disturbed.
- Forests are destroyed by increasing population.
- Ecological balance is distrupted due to the destruction of forests.
Remedies to conserve forests :
- The Government of India implemented a National Forest Policy in 1952.
- In 1980, the Parliament passed Legislative Act and in 1988 a new National Policy was announced.