Notes On Deforestation and Reforestation - CBSE Class 8 Science

Plants are needed for the survival of other living organisms. Forests cover extensive area on earth. But forests are being cleared to avail more land for growing population, industries etc.

Deforestation
It is the process of cutting down the trees. It is referred to as clearing of forests on a large scale to use the land for cultivation, building houses, factories, construction of dams or to obtain wood for making furniture and using it as fuel.

Causes for deforestation
There are two causes Man-made causes and Natural causes for deforestation.
       •  Cases where human beings are responsible for deforestation are known as man-made causes.
       •  Cases which involve nature such as forest fires, severe floods and severe droughts are known as natural causes.



Effects of deforestation
For the survival and well-being of the human species, a vast variety of plants and animals exist on the earth. Forests inhabit a wide variety of plant and animal species. Adverse effects of deforestation are elucidated.
       •  Global warming is the rapid increase in the temperature levels on earth due to increase in the proportion of carbon dioxide in the atmosphere. 
       •  Air pollution caused by combustion of fossil fuels increases carbon dioxide percentage. This gas released into the atmosphere traps sunlight reflected by the earth’s surface and results in an increase in temperature levels on the earth.
       •  Increased temperature levels lead to melting of polar ice caps.
       •  Soil properties of an area affected by deforestation are changed. It also causes soil erosion. Water holding capacity of the soil is reduced.
       •  Fertile land over a long period of time is desertified.
       •  Balance in nature is lost thereby affecting the environment.
       •  Uneven distribution of rainfall. Excessive floods may occur.
       •  Droughts conditions may prevail.
       •  Replenishment of ground water is less as trees absorbing water are lost.
       •  Trees serve as filters of many poisonous gases. Reduction of number of trees in a particular area may increase respiratory ailments in human beings.
       •  Scarcity of raw materials for many industries will be prevalent.
       •  Medicinal plants in the forests are affected.

Biodiversity
Biodiversity is the diversity of plant and animal life found in a particular area. It also deals with the inter-relationship and interaction with their environment.
       •  Food chains are maintained in order to maintain continuity of life. Entire bio-system supports the human life and its needs.
       •  Forests are abode for wild plants and animals. So they have to be preserved.
       •  Biodiversity helps in the preservation of plants which include algae, bryophytes, ferns, gymnosperms and angiosperms. Biodiversity also helps in the preservation of wild animals of all kinds. Animal categories include herbivores, carnivores and omnivores.
       •  Biodiversity also helps in maintaining land areas including hills, plains, ravines, terraces etc.

Degeneration of biodiversity
       •  Degeneration of biodiversity is brought about slowly by biological extinction which results from loss of old forms of life.
       •  Degeneration of biodiversity is fast in calamities such as natural disasters, storms, cyclones, earthquakes, landslides etc.
       •  Degeneration of biodiversity is also brought about by man-made disasters like deforestation, habitation of land, population overgrowth, over exploitation of energy resources, pollution and introduction of exotic species.

Reforestation
It is the planting new trees in destroyed forest area to restore green forests. It is advisable to replant trees of the same species that are found in a forest.
       •  Reforestation in turn increases the population of animal species which exhibit selective feeding habits.
       •  Forests should be restored as they maintain stable food chains and food webs.
       •  Plants and plant products must be maintained judiciously.
       •  Overgrazing should be discouraged on the reforested lands.
       •  Nurseries which provide plantlings for reforestation should be developed.
       •  Wild life sanctuaries, national parks should be developed.



Forest Conservation Act
In India, this act is aimed at preserving and conserving natural forests. To conserve forests literally means conservation of air, water and soil resources. Forest conservation act in turn protects all these resources.
       •  Air pollution is checked by the forests thereby providing us clean air.
       •  Water table and water percentage in the air is maintained stable in the atmosphere by the forests.
       •  Thorough check is posed by forests on soil fertility and soil erosion.

Recycling of paper
Recycling process of paper is of great significance in saving trees. Used paper is sent back to the factories for recycling to produce new papers. 

Summary

Plants are needed for the survival of other living organisms. Forests cover extensive area on earth. But forests are being cleared to avail more land for growing population, industries etc.

Deforestation
It is the process of cutting down the trees. It is referred to as clearing of forests on a large scale to use the land for cultivation, building houses, factories, construction of dams or to obtain wood for making furniture and using it as fuel.

Causes for deforestation
There are two causes Man-made causes and Natural causes for deforestation.
       •  Cases where human beings are responsible for deforestation are known as man-made causes.
       •  Cases which involve nature such as forest fires, severe floods and severe droughts are known as natural causes.



Effects of deforestation
For the survival and well-being of the human species, a vast variety of plants and animals exist on the earth. Forests inhabit a wide variety of plant and animal species. Adverse effects of deforestation are elucidated.
       •  Global warming is the rapid increase in the temperature levels on earth due to increase in the proportion of carbon dioxide in the atmosphere. 
       •  Air pollution caused by combustion of fossil fuels increases carbon dioxide percentage. This gas released into the atmosphere traps sunlight reflected by the earth’s surface and results in an increase in temperature levels on the earth.
       •  Increased temperature levels lead to melting of polar ice caps.
       •  Soil properties of an area affected by deforestation are changed. It also causes soil erosion. Water holding capacity of the soil is reduced.
       •  Fertile land over a long period of time is desertified.
       •  Balance in nature is lost thereby affecting the environment.
       •  Uneven distribution of rainfall. Excessive floods may occur.
       •  Droughts conditions may prevail.
       •  Replenishment of ground water is less as trees absorbing water are lost.
       •  Trees serve as filters of many poisonous gases. Reduction of number of trees in a particular area may increase respiratory ailments in human beings.
       •  Scarcity of raw materials for many industries will be prevalent.
       •  Medicinal plants in the forests are affected.

Biodiversity
Biodiversity is the diversity of plant and animal life found in a particular area. It also deals with the inter-relationship and interaction with their environment.
       •  Food chains are maintained in order to maintain continuity of life. Entire bio-system supports the human life and its needs.
       •  Forests are abode for wild plants and animals. So they have to be preserved.
       •  Biodiversity helps in the preservation of plants which include algae, bryophytes, ferns, gymnosperms and angiosperms. Biodiversity also helps in the preservation of wild animals of all kinds. Animal categories include herbivores, carnivores and omnivores.
       •  Biodiversity also helps in maintaining land areas including hills, plains, ravines, terraces etc.

Degeneration of biodiversity
       •  Degeneration of biodiversity is brought about slowly by biological extinction which results from loss of old forms of life.
       •  Degeneration of biodiversity is fast in calamities such as natural disasters, storms, cyclones, earthquakes, landslides etc.
       •  Degeneration of biodiversity is also brought about by man-made disasters like deforestation, habitation of land, population overgrowth, over exploitation of energy resources, pollution and introduction of exotic species.

Reforestation
It is the planting new trees in destroyed forest area to restore green forests. It is advisable to replant trees of the same species that are found in a forest.
       •  Reforestation in turn increases the population of animal species which exhibit selective feeding habits.
       •  Forests should be restored as they maintain stable food chains and food webs.
       •  Plants and plant products must be maintained judiciously.
       •  Overgrazing should be discouraged on the reforested lands.
       •  Nurseries which provide plantlings for reforestation should be developed.
       •  Wild life sanctuaries, national parks should be developed.



Forest Conservation Act
In India, this act is aimed at preserving and conserving natural forests. To conserve forests literally means conservation of air, water and soil resources. Forest conservation act in turn protects all these resources.
       •  Air pollution is checked by the forests thereby providing us clean air.
       •  Water table and water percentage in the air is maintained stable in the atmosphere by the forests.
       •  Thorough check is posed by forests on soil fertility and soil erosion.

Recycling of paper
Recycling process of paper is of great significance in saving trees. Used paper is sent back to the factories for recycling to produce new papers. 

Videos

Activities

Activity 1
Childrenoftheearth.org has compiled a wonderful animated audiovisual version to information about 'Deforestation'. It displays the options with different headings like Causes, Important facts, Environmental effects and Prevention. User has to click on the icon displayed along with the heading. User has to follow instructions and do necessary action to obtain the information. 'Back to Menu' button is displayed on every page allowing the user to go to menu page.
Go to Activity

Activity 2
Jasper.k12.ga.us has sparked an interactive audiovisual simulation to explain difefrent concepts like 'vanishing biodiversity', 'endangered species', 'environmental degradation'. Use has to click on the icons displayed below. As the respective pages are displayed, user can view the animation and can pause the animation. On the map, user needs to click on the numbers displayed. According to the clicked number, information is provided at the bottom. 
Go to Activity

References

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