Natural Vegetation

Natural vegetation refers to the plant community which has grown naturally without any human assistance and has not been disturbed over a long time, so as to allow its individual species to adjust themselves fully to the climate and soil conditions.

Natural vegetation of a place closely related to the climate of that place more importantly on the rainfall at that place. The areas having high rainfall have dense evergreen forest while areas with very less rainfall have thorny desert vegetation. Similarly, the cold places where snowfall are common have coniferous trees.

Trees are very important to man due to the following reasons:

1. Trees provide timber for house-making and furniture, fuel, fruits, herbs, honey, bamboo, canes and fibres.
2. Trees help to purify the air by absorbing carbon dioxide and other pollutants, and releasing oxygen.
3. Trees can help to reduce soil erosion by holding the soil in place with their roots. They also prevent floods.
4. They provide raw material to many industries, e.g., paper.
5. Trees can also provide food, medicine, and other resources for humans.

The percentage of forest cover on land in India is 21.02%.

There is shrinkage of forest cover in India due to following reasons:

1. Urbanization/Industrialization.
2. Increasing population.
3. Conversion of forest land to agricultural land.
4. Faulty agricultural practices like Jhooming cultivation or shifting agriculture.
5. Unauthorized cutting of trees by timber merchants.
6. Increased demand for forest products.
7. Construction of multipurpose river valley projects.
8. Forest fires.

Precautions that can be taken to reduce this shrinkage are:

1. Stopping unauthorized deforestation.
2. Promoting afforestation in lands unfit for agriculture.
3. Following reafforestation at the places from where trees have been cut.
4. Measures should be taken to avoid forest fires.
5. Strict regulation to avoid encroachment of forest land.
6. Using alternative sources of energy and avoiding felling of trees for firewood.

A few forest products are furniture, fuel, fruits, herbs, honey, bamboo, canes, fibres and lac.

The factors that influence the natural vegetation of a place are:

1. Rainfall
2. Relief
3. Temperature
4. Altitude
5. Soil

The characteristics of Tropical Evergreen forest are:

1. As they are found in the areas of heavy rainfall, they are also known as 'rain forests'.
2. The thick ground cover of forest is characterized by climbers and epiphytes. Bamboo and ferns are also common.
3. As the do not shed their leaves at the same time, they remain evergreen and are called 'Tropical evergreen forests'.

Some important trees of these forests are Rosewood trees, Sisam and Gurjan.

Tropical deciduous forests are the economically most important vegetation belt of India because of the following reasons:

1. They provide valuable timber and several other forest products.
2. They are not so dense which make them easier to exploit.
3. They cover a larger area than evergreen forest.

Deciduous Monsoon forests are found in the belt running along the Western Ghats, surrounding the belt of Evergreen forests both on eastern and western slopes.

The Deciduous Monsoon forests are found in areas of average temperature of about 24°C to 27°C and with rainfall between 150 to 200 cm. Such conditions are available in the Western Ghats providing the environment for deciduous forests to grow.

1. Teak — It is used for furniture, construction of houses and shipbuilding.
2. Sal — It is used in making railway sleepers.
3. Sandalwood — Sandalwood oil is used in perfumery and cosmetics.
4. Semul — It is used making matchboxes, toys and packing cases.
5. Myrobalan — Its fruit is used for tanning leather and for dyeing purpose.
6. Eucalyptus — Eucalyptus oil is used for medicinal purposes.

The main features of the Mountain forests are:

1. Mountain forests consist of mixed deciduous and coniferous forests.
2. They occur in the transition zone of mixed forest and coniferous forests.

These forests are found in the temperate zone of the Himalayas, from Kashmir to Assam at varying altitude. In the south, they are found in Nilgiri and Annumalai Hills at an elevation between 1000 m to 1500 m.

Desert and semi-desert vegetation grow in the arid areas of average temperature of 25°C to 27°C and with rainfall of less than 25 cm.

The characteristics of the Mangrove forests are:

1. Mangrove vegetation is characterized by breathing roots or pneumatophores which act as respiratory organs.
2. Its stilt like roots remain submerged under water but can be seen at low tide.
3. These forests are very dense.
4. They have profuse growth with tangle of climbers, which is an adaptation for survival in soft and shifting mud.

The other names of Mangrove forests are Tidal forest or Littoral Forest.

Afforestation — The act or process of establishing a forest by planting fresh trees especially on land not previously forested is called afforestation. This is done to increase the land under forest.

Deforestation — The act of depletion of forest cover due to unauthorized felling of trees is called deforestation.

The two characteristic features of Tropical Evergreen forest that make it difficult to exploit are:

1. They have very dense undergrowth due to tangled mass of canes, palms, bamboos, ferns and climbers.
2. There is lack of transport facilities.

The Deciduous Monsoon forests are found on the eastern part of South India because the area has average rainfall between 150 to 200 cm and the temperature lies in the range of 24°C to 27°C.

Rajasthan and South-West Punjab are two states in India where thorn and scrub forests are found. The Babul and Khair trees are found in these areas.

Mangrove vegetation with breathing roots or pneumatophores which act as respiratory organs are found in saline environment under tidal influence. The most important tree associated with the Mangrove vegetation are 'Sundari trees'. These are the trees after which the forest has been named as Sunderbans. The sundari trees are used for boat building as it wood is very hard, strong and durable.

The wood of Sundari trees is very hard, strong and durable. These characteristics make it ideal for boat building.

The level of pollution around steel cities is much higher than other cities. During the manufacture of steel, air emissions from the manufacturing plants emit particulate matter, sulphur oxides, nitrogen oxides, hydrocarbons and hydrogen fluoride which pollute the air. Besides these, steel plants emit significant dust levels of about 20 kilograms per metric ton of steel. Growing forests around them helps to lower the pollution as the trees act as a barrier for the dust and purify the air.

The two states where Deodar trees are grown are Himachal Pradesh and Kashmir. The Deodar tree wood is used for railway sleepers and house construction.

Mangrove vegetation is found along the coastal strip of the Ganga delta.

The total forest cover of the total geographic area of India is 21% but the effective forest cover as revealed by various surveys is between 12% - 14%.

1. The trees in Tropical Evergreen forests do not shed their leaves at the same time. Therefore, they remain green throughout the year and are called Evergreen forests.
2. Tropical Evergreen forests are called rain forests because they are found in the areas of heavy rainfall.
3. Tidal forests are typically found in wetlands with a regular tidal influence. They are adapted to the regular flooding that occurs in these areas. Hence, tidal forests occur in and around deltas as deltas provide the ideal conditions needed by tidal forests to thrive.

1. Mangrove or Littoral forests
2. Myrobalan
3. Deciduous Monsoon forests

they do not shed their leaves at the same time

Deodar

Tropical evergreen forest

planting fresh trees

Rosewood

heavy rainfall (more than 200cm) in and around delta

to survive in marshes and submerged areas

they occur in the transition zone of mixed forest and coniferous forest

because of lack of nutrients and dehydration in the desert

Coniferous