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Deforestation and afforestation - class-VIII

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Read the given statements and select the correct option. 
Statement 1 : Reforestation is the process of restoring a forest that once existed but was removed at some point of time in the past.
Statement 2 : Reforestation may occur naturally in a deforested area, however it can be speeded up by planting trees with due consideration to biodiversity that earlier existed in that area.

  1. Both statements 1 and 2 are correct.

  2. Statement 1 is correct but statement 2 is incorrect.

  3. Statement 1 is incorrect but statement 2 is correct.

  4. Both statements 1 and 2 are incorrect.


Correct Option: A
Explanation:

Reforestation is the natural or intentional restocking of existing forests and woodlands (forestation) that have been depleted, usually through deforestation. Reforestation can be used to rectify or improve the quality of human life by soaking up pollution and dust from the air, rebuild natural habitats and ecosystems, mitigate global warming since forests facilitate biosequestration of atmospheric carbon dioxide, and harvest for resources, particularly timber, but also non-timber forest products. Reforestation usually involves replanting areas of forest which have previously been damaged or destroyed, using native tree species. Sometimes forests are able to regenerate naturally if sufficient trees remain nearby and seeds can be dispersed into the deforested areas via animals or wind. However, areas of forest which have been severely degraded are unlikely to be able to regenerate naturally and need to be replanted by hand using native tree species.

So the correct option is 'both statements 1 and 2 are correct'.

The total percent of land in the world under forest area is

  1. 26%.

  2. 31%.

  3. 36%.

  4. 41%.


Correct Option: B

Plants remove carbon in the form of:

  1. Carbonates

  2. Carbon monoxide

  3. Bicarbonates

  4. Carbon dioxide


Correct Option: D
Explanation:

Plants remove carbon in the form of carbon dioxide from the atmosphere during the process of photosynthesis.

Deforestation has an alarming effect on

  1. Increase in grazing area

  2. Sunlight

  3. Weed control

  4. Soil erosion or desertification of habitat


Correct Option: D

Deforestation leads to

  1. Soil erosion

  2. Global warming

  3. Soil protection

  4. Both A and B


Correct Option: D
Explanation:

Deforestation is removal or deterioration of forest cover of an area. It results in shirking fuelwood, reduced timber, change in climate, soil erosion, flash floods, siltation, drought, loss of biodiversity, less rainfall, global warming etc.

Thus, the correct answer is option D.

What is the main cause for the extinction of some species in tropical forest?

  1. Deforestation

  2. Afforestation

  3. Pollution

  4. Soil erosion


Correct Option: A
Explanation:
Deforestation is the depletion of forest resources. It's main cause is the explosion of human and livestock population with the increased demand requirements of the basic needs. The major effect of deforestation is the loss of precious wild life, rare species of flora and fauna. Directly or indirectly, deforestation caused intensified soil erosion, accentuated floods, drought and the worst pollution.
So, the correct answer is 'Deforestation'.

Forest destruction results in

  1. Loss of wild life

  2. Floods and drought

  3. Soil erosion

  4. All the above


Correct Option: D
Explanation:

Forest destruction i.e. deforestation has many after effects, it leads to soil erosion, loss of habitat, etiction of wildlife, floods & drought conditions.

So, the correct option is 'All the above'.

Deforestation will decrease

  1. Soil erosion

  2. Land slides

  3. Soil fertility

  4. Rainfall


Correct Option: D
Explanation:

Deforestation is the process of extensive cutting of trees, which finally leads to the destruction of forests as the trees are removed in large numbers, the water cycle gets disturbed which results in decrease in rainfall

So, the correct answer is 'Rainfall'

Extensive planting of trees to increase forest cover is called

  1. Afforestation

  2. Agroforestry

  3. Deforestation

  4. Social forestry


Correct Option: A
Explanation:

Afforestation is the process of planting a large number of trees for increasing forest cover, while deforestation is the process of cutting trees in large numbers from the forest.

So, the correct answer is 'Afforestation'

Deforestation generally decreases

  1. Global warming

  2. Drought

  3. Rainfall

  4. Soil erosion


Correct Option: C
Explanation:

Deforestation means clearing or removal of forest by extensive cutting of trees, water cycle which goes on in the environment gets disturbed by lack of  sufficient number of trees. Trees increase the amount of rainfall due to transpiration, therefore if number of trees decrease rainfall also decreases, while other factors given in the options A, B & D increases.

So, the correct answer is 'Rainfall'

Decrease in species diversity in tropical countries is mainly due to

  1. Urbanisation

  2. Pollutionx

  3. Deforestation

  4. Soil erosion


Correct Option: C
Explanation:

When there are no more individuals of a species (plant or animal) alive anywhere in the world, the species is said to be extinct. A decrease in the species diversity progresses to extinction if left uncontrolled. Extinction is also known as the process of dying out. The process is a completely natural part of evolution. But sometimes extinctions happen at a higher and a faster rate than usual. Factors such as large body size, small population, massive habitat loss and position at a higher trophic level favor extinction. As forests are the main habitat for the wild animals, their loss favors the extinction of the same.

So, the correct answer is 'Deforestation'.

Choose the wrong pair

  1. Salvodora - Desert

  2. Cenchrus - Savanna

  3. Ables - Coniferous forest

  4. Quercus - Broad leaf forest

  5. Tectona - Temperate forest


Correct Option: E

Main cause of extinction of species from tropical areas is

  1. Afforestation

  2. Deforestation

  3. Pollution

  4. Soil erosion


Correct Option: B
Explanation:

When there are no more individuals of a species (plant or animal) alive anywhere in the world, the species is said to be extinct. Extinction is also known as the process of dying out. The process is a completely natural part of evolution. But sometimes extinctions happen at a higher and a faster rate than usual. Factors such as large body size, habitat loss, small population and position at a higher trophic level favor extinction. Since the species residing in the tropics have their major habitat in the form of forests, thus deforestation causes, extinction of such species.

So, the correct answer is 'Deforestation'.

Extensive plating of trees to increase forest cover is called :

  1. Afforestation

  2. Agroforestry

  3. Deforestation

  4. Plantation


Correct Option: A

Deforestation does not cause ...........

  1. Desertification

  2. Global warming

  3. Drought

  4. Forest fires


Correct Option: D
Explanation:

Since deforestation means cutting down of trees. So, it will result in desertification of an area, global warming because of increase in CO$ _2$ in the environment since plants are not available to fix it by photosynthesis, and can cause drought because of imbalance in water cycle of an area. But, deforestation will never cause forest fires because the forests are not available to catch the fire as they are being cut down in case of deforestation.

So, the correct answer is 'Forest fire'.

The cutting down of trees and setting them on fire and raising crops on the resulting ash is called:

  1. Pyrolysis

  2. Jhum

  3. Taungya system

  4. Shift cultivation


Correct Option: B

Many wild animals have either become extinct or are endangered mainly due to 

  1. Scarcity of food

  2. Over crowding

  3. Hunting

  4. Deforestation


Correct Option: D
Explanation:

An endangered species is the species whose population faces a sudden downfall. In the case of wild animals, their habitat is the forest and deforestation of the forests due to ecological disasters, or use of timber for the construction of buildings makes them insecure in their homestead. 

Moving away to nearby locations not only disturbs the food chain, breeding grounds and habitats of these wild animals but they are also faced with threats of being hunted and poached for the benefit of the human beings. 
So, the correct answer is 'Deforestation'

Which method is most effective in controlling floods?

  1. Digging deep canals

  2. Reforestation

  3. Deforestation

  4. Constructing dams


Correct Option: B
Explanation:

Loss of vegetation (deforestation) results in an increased risk of flooding. With natural forest cover, the flood duration should decrease. Reducing the rate of deforestation should improve the incidents and severity of floods. Reforestation and afforestation are two strategies to increase the vegetation cover, that can improve infiltration and interception rates, and thus regulate flood peaks. Reforestation refers to planting trees in areas, where they have been cut down, while afforestation means planting trees, where they have never existed. Dams and reservoirs are effective in controlling floods by reducing peak flows. 

An effect of deforestation is

  1. Desertification

  2. Soil erosion and floods

  3. Depletion of wildlife

  4. All of the above


Correct Option: D
Explanation:

Deforestation is the destruction of forest which causes loss of habitat and other problem like

1. Reduced biodiversity: when forest cover is removed, wildlife is deprived of habitat and becomes more vulnerable to hunting. 
2. The release of greenhouse gas emissions: deforestation causes 15% of global greenhouse gas emissions. 
3. Disrupted water cycles: as a result of deforestation, trees no longer evaporate groundwater, which can cause the local climate to be much drier. 
4. Increased soil erosion: deforestation accelerates rates of soil erosion, by increasing runoff and reducing the protection of the soil from tree litter. 
5. Disrupted livelihoods: millions of people rely directly on forests, through shifting cultivation, hunting and gathering and by harvesting forest products, such as rubber. 
Thus, the correct answer is option D.

Which of the following defines the effect of deforestation on cities (urban areas)?

  1. Increase the risk of floods and droughts

  2. Global warming

  3. Both A and B

  4. None of the above


Correct Option: C
Explanation:
Effects of deforestation on the Earth:
As a result of deforestation, chances of desertification, droughts, floods, etc. increase. Deforestation can also increase the level of CO$ _2$ in the atmosphere, it will lead to an increase in temperature i.e., global warming. As a result, the entire natural water cycle will get disrupted. This again increases the risk of natural calamities.

Which of the following defines the effect of deforestation on earth?

  1. Increased chances of desertification, droughts, floods

  2. Increase in the level of $O _2$

  3. Global warming

  4. Both A and C


Correct Option: D
Explanation:
Effects of deforestation on the Earth:
As a result of deforestation, chances of desertification, droughts, floods, etc. increase. Deforestation can also increase the level of CO$ _2$ in the Earth, it will lead to an increase in temperature i.e., global warming. As a result, the entire natural water cycle will get disrupted. This again increases the risk of natural calamities.
Global Warming is the increase of Earth's average surface temperature due to the effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth.
Hence, the correct answer is option D.

Which of the following defines the effect of deforestation on villages? 

  1. Top layer of the soil will be easily removed

  2. Soil erosion

  3. Less fertile soil

  4. All of the above


Correct Option: D
Explanation:

Effects of deforestation on villages- Roots of plants hold soil particles together. In the absence of plants, the top layer of the soil will be easily removed by the action of high-speed winds or water flow. Thus, deforestation increases the chances of soil erosion. As a result, soil loses humus and become less fertile. Hence, a fertile land, which is a source of living for farmers in villages, gets converted into a desert.

Therefore, the correct answer is option D.

Which of the following defines the effect of deforestation on wild animals?

  1. Habitat of wild animals is developed, then their numbers would automatically decline.

  2. Habitat of wild animals is destroyed, then their numbers would automatically decline.

  3. Habitat of wild animals is destroyed, then their numbers would increase.

  4. All of the above.


Correct Option: B
Explanation:
Deforestation is the clearing of forest which causes loss of habitat. If the habitat of wild animals is destroyed, then their numbers would automatically decline as they start moving towards urban and rural areas to meet their requirement and search a better option for their survival.
So, the correct answer is option B.

Deforestation is the major cause of

  1. Transpiration

  2. Genetic erosion

  3. Desertification of habitat

  4. All of the above


Correct Option: C
Explanation:

Deforestation is the cutting of trees. When trees are lost due to deforestation, the result can be a drier climate and desertification, or the transformation of the once fertile land to desert.

Deforestation is the term that describes the cutting down or clearing of trees from a wooded area. 
Tree roots absorb water from the ground and return water vapor back to the atmosphere. If trees are removed and can no longer contribute to the water cycle and thus, transform into a much drier climate. This dry environment can spread due to a decrease in atmospheric water vapor and results in a decline in precipitation levels in the area and leads to the desertification
Thus, the correct answer is option C.

Deforestation generally decreases 

  1. Rainfall

  2. Soil erosion

  3. Drought

  4. Global warming


Correct Option: A
Explanation:

When forests are destroyed, the atmosphere, water bodies and the water table are all affected. Trees absorb and retain water in their roots and some of this moisture is transpired into the atmosphere, regulates the water cycle. When this process is broken, the atmosphere and water bodies begin to dry out. 

Therefore, the correct answer is option A.

Frequent floods in plains of Northern India is due to

  1. Excessive rainfall

  2. Siltation of dams

  3. Deforestation in catchment areas

  4. Agriculture


Correct Option: C
Explanation:

Frequent floods in plains of Northern India is due to deforestation in catchment areas. Deforestation in the catchment area has led to an increase in the silt content of the river flow. Bihar is India's most flood-prone State, with 76% of the population in the north Bihar living under the recurring threat of flood devastation.

Removal of vegetation cover has caused widespread erosion in Western Ghats, Uttar Pradesh and in Himachal Pradesh.

Deforestation leads to reduced rainfall due to

  1. Level of $CO _2$ in the atmosphere rises

  2. Global warming

  3. Disturbance in natural water cycle

  4. All of the above


Correct Option: C
Explanation:

Green plants lose water by the process of transpiration. This contributes a lot towards atmospheric moisture. Thus, green plants have major contribution in precipitation. Due to this, deforestation leads to reduced rainfall. Thus, the correct answer is option C.

What are the consequences of deforestation?

  1. Soil erosion

  2. Loss of biodiversity

  3. Floods and droughts and climate change due to global warming

  4. All of the above


Correct Option: D
Explanation:
Causes of deforestation are as follows:
  • Clearing land for human habitation and cultivation
  • The need of wood for building houses and factories.
  • The need of wood for making furniture.
Consequences of deforestation are as follows:
  • Soil erosion
  • Depletion of groundwater
  • Flash flood
  • Global warming
  • Loss of biodiversity
  • Droughts and climate change due to global warming

Desertification is due to

  1. Deforestation

  2. Soil-erosion due to water

  3. Soil-erosion due to wind

  4. Very high temperature and low rainfall


Correct Option: A
Explanation:

Desertification is defined as a process of land degradation due to climatic variations and human activities. Overgrazing is the major cause of desertification worldwide. Other factors are urbanization, overdrafting of groundwater and deforestation. Thus the correct answer is option A.

Which of the following provides nutrients to the seedlings to grow in forests?

  1. Bacteria

  2. Fungi

  3. Decaying animal dung

  4. Beetles and grubs


Correct Option: C
Explanation:

Animals living in the forest include herbivores and carnivores. The dung of these animals are decomposed by insects living in the soil. This contributes to the fertility of the soil by adding organic matter and nutrients, such as nitrogen, that is trapped by bacteria in the soil. This provides nutrients to the seedlings to grow in forests. Thus the correct answer is option C.

Destroying a forest means destroying

  1. Ecosystem

  2. Plant life

  3. Population of wild life

  4. Food and shelter of wild animals


Correct Option: A
Explanation:

Destroying a forest has many negative effects on the environment. Seventy percent of earth's terrestrial animals and plants live in forests. The most adverse impact is the loss of habitat for millions of species leading to disturbance in the food chain that is an important component of the ecosystem. Thus the correct answer is option A.

Which of the following involves the clearing of the forest?

  1. Afforestation

  2. Deforestation

  3. Soil erosion

  4. None of the above.


Correct Option: B
Explanation:

Cutting of trees or clearing the forest is called as deforestation. Deforestation not only affects the land from which it is cleared but it also affects the environment. Trees are very important for the environment because they help in reducing pollution by releasing more oxygen. They protect the environment in many ways and hence, cutting of the tree is harmful and affects the environment.

Thus, the correct answer is option B.

What is reforestation?

  1. Cutting of trees.

  2. Restocking of the destroyed forests by planting new trees.

  3. Conversion of fertile soil into forest.

  4. Conversion of forest into fertile soil.


Correct Option: B
Explanation:

Reforestation is restocking of the destroyed forest by planting new trees. We should plant at least as many trees as we cut. Reforestation can take place naturally also.

Thus, the correct answer is option B.

Which of the following is the consequence of deforestation?

  1. Global warming

  2. Erosion of the top layer of soil

  3. Increase in the level of carbon dioxide in air

  4. All of the above


Correct Option: D
Explanation:

Deforestation is the process of removal or the cutting down of the trees. The absence of the trees results in an increase in the concentration of carbon dioxide which causes global warming. The roots of the plants help in holding the soil and deforestation causes soil erosion from the upper layer of the soil. The plants take up the carbon dioxide from the air for photosynthesis. When there are no trees, there is increase in the level of carbon dioxide.

Thus, the correct answer is option D. 

Which of the following are the adverse effects of deforestation?

  1. Reduced rainfall

  2. Soil erosion

  3. Destruction of habitat

  4. All of these


Correct Option: D
Explanation:

Deforestation is removal, decrease or deterioration of forest cover of an area. It causes shrinkage of fuelwood, reduced timber supply, change in climate, flash floods, soil erosion, siltation, cyclones, drought, desertification, reduced rainfall and destruction of habitat. Thus, the correct answer is option D.

Which of the following natural disasters affect habitat in the environment?

  1. Droughts

  2. Floods

  3. The thinning of the ozone layer

  4. All of these


Correct Option: D
Explanation:

Drought is the condition of shortage of water which affects all life forms. Flood is the condition of the overflow of water on land that can submerged plants, human-made articles and thinning of the ozone layer increases the global warming and climate change which affects the flora and fauna. All these conditions can harm the organisms and their habitat and thus, can threat to the biodiversity.

What is / are the likely consequences of deforestation?

  1. Carbon dioxide in the air increases.

  2. Destruction of habitats takes place.

  3. Mineral salts in the soil are washed away.

  4. All of the above.


Correct Option: D
Explanation:

Deforestation is the depletion / destruction of forest resources. Its main cause is the explosion of human and livestock population with the increased demand of the basic needs. The major effect of deforestation is the loss of precious wildlife, rare species of flora and fauna due to loss of habitat, soil erosion, accentuated floods, drought, pollution and increased level of carbon dioxide.

Deforestation is caused due to

  1. grazing

  2. timber

  3. Cultivation

  4. all of these


Correct Option: D

What is the effect of deforestation on amount of $CO _2$ in atmosphere?

  1. It increases

  2. It decreases

  3. It remains unchanged

  4. Cannot be predicted


Correct Option: A
Explanation:

Deforestation is the permanent destruction of forests in order to make the land available for other uses. Deforestation has many negative effects on the environment. The most dramatic impact is a loss of habitat for millions of species. Seventy percent of Earth's land animals and plants live in forests, and many cannot survive the deforestation that destroys their homes. Deforestation also drives climate change. Since, trees purify air by absorbing carbon dioxide from atmosphere, loss of trees would result into increase in level of carbon dioxide.

Deforestation refers to

  1. planting of trees

  2. cultivation of crops

  3. disappearance of forests

  4. development of plantation


Correct Option: C

Most fertile layer of soil is

  1. top layer

  2. organic layer

  3. middle soil layer

  4. all of these


Correct Option: A

Replanting forest at places where they were destroyed is called :

  1. reforestation

  2. desertification

  3. replantation

  4. degradation


Correct Option: A
Explanation:

A- Reforestation is natural or intentional restocking of forests that have been depleted mainly due to deforestation or any natural calamity. Reforestation gives boost to the wild life and helps in improving the air quality, climate control, improvement in natural resources and many more advantages for living beings.

Which of the following prevents afforestation in deserts?

  1. Goat and grazing animals

  2. Local resident

  3. Unfertility of soil

  4. Low rainfall


Correct Option: D
Explanation:

Major problem in desert is lack of rainfall. While grazing of animals and local residents can be controlled but without rainfall growth of trees and afforestation is not possible. 

Forest reserves can be protected through all measures except

  1. Laws inhibiting tree felling

  2. Laws allowing tree felling 

  3. Prohibition of hunting

  4. Human population control


Correct Option: B

Plants control the humidity in air by

  1. Photosynthesis

  2. Transpiration

  3. Photorespiration

  4. All of the above


Correct Option: B
Explanation:

Plants absorb water from the soil and looses it to the atmosphere by transpiration,hence,control the humidity in air by acting as a water exchanger between ground and atmosphere.

Deforestation causes__________ to linger in the atmosphere.

  1. $CO _2$

  2. $H _2O$

  3. $O _2$

  4. $N _2$


Correct Option: A
Explanation:

Deforestation causes carbon dioxide to linger in the atmosphere. As carbon dioxide accrues, it produces a layer in the atmosphere that traps radiation from the sun. The radiation converts to heat which causes global warming, which is better known as the greenhouse effect.

The establishment of forest growth on areas that either had forest or lacked it is known as

  1. Deforestation.

  2. Organic farming.

  3. Forestation.

  4. None of these.


Correct Option: C

The establishment of a forest or stand of trees in an area where there was no previous tree cover is known as

  1. Deforestation.

  2. Afforestation.

  3. Forestation.

  4. None of these.


Correct Option: B

Forests return most of the water that falls as precipitation to the atmosphere by

  1. Phororespiration

  2. Respiration

  3. Transpiration

  4. All of the above


Correct Option: C
Explanation:

Transpiration is the process by which plants loose water through their leaves in the atmosphere.

Which of the following contributes the most towards deforestation?

  1. Logging

  2. Commercial agriculture

  3. Subsistence farming

  4. None of the above


Correct Option: C
Explanation:

Subsistence farming is responsible for $48$% of deforestation; Commercial agriculture is responsible for $32$%; logging is responsible for $14$%, and fuel wood removals make up $5$%.

The results of deforestation is/are:

  1. the reduction in water content of the soil

  2. the increase in water content of the soil

  3. drier climate

  4. increases moisure content of air


Correct Option: A,C
Explanation:

The water cycle is affected by deforestation.Trees extract groundwater through their roots and release it into the atmosphere. When part of a forest is removed, the trees no longer transpire this water, resulting in a much drier climate.Deforestation reduces the content of water in the soil and groundwater as well as atmospheric moisture. The dry soil leads to lower water intake for the trees to extract.Deforestation reduces soil cohesion, so that erosion,flooding and landslides ensue.

Desertification is a type of

  1. food preparation method for plants

  2. afforestation method

  3. land degradation

  4. None of these


Correct Option: C
Explanation:

Desertification is a type of land degradation in which relatively dry area of land becomes increasingly arid, typically losing its bodies of water as well as vegetation and wildlife.

The hard mineral crust formed at or near the surface of soil is known as

  1. Duripan.

  2. Duricrust.

  3. Anaerobic soil.

  4. Peat.


Correct Option: B

If deforestation is done in large scale, this natural calamity may occur

  1. Volcanic eruption

  2. Earthquakes

  3. Global warming

  4. Tsunamis


Correct Option: C
Explanation:

If deforestation is performed, there will be no trees so, the amount of the greenhouse gasses will increase in the atmosphere. These greenhouse gasses trap heat from the infrared radiation in the atmosphere and increases the atmosphere's temperature i.e, global warming. 

Thus, the correct answer is option C. 

............ is a man-made source of air pollution.

  1. Desert

  2. Farming

  3. Dust storms

  4. Volcanic eruptions


Correct Option: B
Explanation:

Farming is considered as the major source of air pollution due to man. This is the man-made source of air pollution which allows the particles to enter the atmosphere. The movement of tractors will cause the soil particles to rise up in the air. The particles from the fertilizers and pesticides spray enter the atmosphere. Also during harvesting and husking, the small particles in the form of pollens and husks can result in air pollution. 

Thus, the correct answer is option B. 

Which  one of the following is not a reason for shortage of usable water?

  1. Over exploitation

  2. Climate change

  3. Deforestation

  4. Decrease in sea level


Correct Option: D
Explanation:

Overuse of the water resources will result in the exhaustion of the water supply. The climatic change has resulted in global warming and seasonal variations. There is a decrease in the annual rainfall which was received by a region due to shortening of the seasons. Deforestation has resulted in a decrease in the number of trees which thereby affect the amount of rainfall which was received. There is soil erosion which results in water run off.The decrease in the level of the sea is not a reason for the shortage of usable water. 

Thus, the correct answer is option D. 

Deforestation may reduce the chances of

  1. Rainfall

  2. Frequent cyclones

  3. Erosion of surface soil

  4. Frequent land slides


Correct Option: A
Explanation:

Deforestation is the process of cutting or removal of forest to fulfill the need of the population. It has many negative impacts on the environment such as loss of species, soil erosion and reduces rainfall. The tree absorbs water from soil for photosynthesis and produces water vapor that is released into the atmosphere which in turn causes rainfall. If there will be less number of the tree then rainfall will also decrease. Thus, the correct answer is option A.

If we remove half of the forest cover of earth, what kind of crisis will occur?

  1. Many species would become extinct.

  2. Population, pollution and ecological imbalance will rise.

  3. Energy crisis will commence.

  4. The remaining forest will cause imbalance.


Correct Option: B
Explanation:

Forests occupy more than 30 percent of Earth's land surface and account for 50 percent of plant productivity. Therefore 45% of the carbon stored on land is tied up in forests. Further, these being the dominant terrestrial ecosystem, the forest account for 75% of the gross primary productivity of the Earth's biosphere and 80% of the plant biomass. Removing half the forest cover, will not only bring in an increase in the population of human beings and other living organisms but will also bring about increased pollution and a great ecological imbalance.

Recurrence of floods in the plains of North India is due to excessive

  1. Siltation of dams

  2. Rainfall

  3. Agriculture

  4. Deforestation in catchment area


Correct Option: D
Explanation:

Floods are common in north India because of excessive deforestation in the catchment areas. Roots of the trees keep the soil together and drain the extra water into the underground water reservoir. Due to deforestation (cutting down of the trees), the soil is no longer able to hold or drain the excess water thus leading to floods. 

In recent years, there has been an increasing incidence of floods in the plains of northern India because

  1. There has been an increase in annual rainfall

  2. The rate of silting of darns has gone up

  3. There has been increased deforestation in the catchment areas

  4. Increased areas of land is being self cultivated


Correct Option: C

Deforestation is the major causal agent of

  1. Depletion of natural resources

  2. Environmental pollution

  3. Desertification of habitat

  4. Genetic erosion


Correct Option: C
Explanation:
Deforestation leads to erosion of top fertile layer of the soil, it also depletes the soil of decomposing microorganisms and thus humus. Absence of humus makes the soil dry i.e, its water holding capacity is decreases. So no vegetation grows in the soil, further depleting the condition of the soil leading to desert like condition. Hence, also called desertification
So, the correct answer is 'Desertification of habitat'

Which one is not a natural factor for causing soil erosion?

  1. Gullying

  2. Clips

  3. Rilling

  4. Deforestation


Correct Option: D
Explanation:

Soil erosion is the process of weathering of top layer of soil either due to natural factor or artificial factor. The natural factors are called as erosion agents. These include water, wind, ice. Water produces 4 types of erosion, namely splash erosion, sheet erosion, rill erosion, and gully erosion. Gully erosion occurs due to drainage of soil by surface water runoff. Rilling erosion is the erosion due to concentrated water running through little streamlets. Deforestation is the artificial or man-made factor for causing soil erosion.

Thus, the correct answer is 'Deforestation.'

Planting of trees, shrubs and others in between crop plants for stabilisation of soil is

  1. Taungya

  2. Social forestry

  3. Production plantation

  4. Agroforestry


Correct Option: D
Explanation:
  • Agroforestry is the planting of trees, shrubs, and others in between crop plants.
  • Advantages of agroforestry practices include Increased crop production and economic gain. Soil conservation and improved soil quality. Sequestration of atmospheric carbon.
  • Hence Planting of trees, shrubs, and others in between crop plants for stabilization of soil is Agroforestry.
  • So, the correct answer is 'Agroforestry'.

Decreased rainfall in northern areas is due to

  1. Changes in sun

  2. Global phenomenon

  3. Deforestation in catchment areas

  4. Deforestation in evaporating area near equator


Correct Option: C
Explanation:

Deforestation leads to irregular water cycle, as a result there is decreased rainfall, deforestation in catchment areas is the main resaon behind the decreased reainfall in northern region.

So, the correct option is 'Deforestation in catchment areas'.

Deforestation does not lead to

  1. Quick nutrient cycling

  2. Soil erosion

  3. Alteration of local weather conditions

  4. Destruction of natural habitat of wild animals


Correct Option: A
Explanation:

Deforestation leads to soil erosion, alteration of local weather conditions, destruction of natural habitat of wild animals, but it does not lead quick nutrient cycling

So, the correct answer is 'Quick nutrient cycling'

Afforestation in relation to urban development is component of

  1. Social forestry

  2. Integrated forest development

  3. Agroforestry

  4. Fuel forestry


Correct Option: B
Explanation:
  • Afforestation is the process of planting trees, or sowing seeds, in a barren land devoid of any trees to create a forest. The term should not be confused with reforestation, which is the process of specifically planting native trees into a forest that has decreasing numbers of trees.
  • Hence Afforestation in relation to urban(cities) development is a component of Integrated forest development.
  • So, the correct answer is 'Integrated forest development'.

A movement similar to Chipko which has spread in South is

  1. Uliso

  2. Appiko

  3. Belesu

  4. Balasu


Correct Option: B
Explanation:
The Chipko Movement was launched by Chandi Prasad Bhatt and Sunder Lal Bahuguna in 1973, against large scale cutting of trees by timber contractors in the Uttarakhand hills. The movement started in Chamoli district of Garhwal region in Uttarakhand. Local hill women from villages were organised and made aware of ecological threat in the hills. They actively participated in the campaign. They embraced or hugged the trees when the timber contractors reached and forced them to leave. This novel campaign for saving hill forests and greenery spread all along the hill region and to Karnataka in South also in 1983. In Karnataka, it was named as Apikko movement which was started by Appu and Mamtha in a small village named Gubbi Gadde near Sirsi.
So, the correct answer is 'Apikko'.

Maximum damage to forest cover is caused by

  1. Edaphic factors

  2. Climatic factors

  3. Biotic factors

  4. Physiographic factors


Correct Option: C
Explanation:
A. Edaphic factors are the abiotic factors that relate to structure and composition of soil.
B. Climatic factors include rain, wind, earthquake etc. which are related to climate.
C. Biotic factors are the living components of an ecosystem which include producers and consumers.
D. Physiographic factors are the factors associated with physical nature and topography of an area.
Maximum damage to forest is caused by biotic factors as overgrazing destroy vegetation and also due to human activities. 
So, the correct answer is 'Biotic factors'.

The term 'Phytoremediation' refers to the _________________.

  1. Use of plants for removing pollutants from the environment

  2. Use of plants as remedies to cure diseases

  3. Use of plants for restoration of degraded forests

  4. Use of plants in the retention of soil water


Correct Option: A

The easiest way to improved the denuded forests of teak in India in to.

  1. Apply mycorrhiza

  2. Apply fertilizer

  3. Add bacterial culture

  4. Use green algae


Correct Option: A

What is the importance of forest as a resource?

  1. It improves water holding capacity of soil.

  2. It provides habitat, food, protection to wild life.

  3. It help in balancing $CO _{2}$ and $O _{2}$ of atmosphere.

  4. All of the above.


Correct Option: D
Explanation:
Forests and biodiversity is key to all life forms. The richer the diversity of life, the greater the opportunity for medical discoveries, economic development and adaptive responses to such new challenges as climate change.
Forests are renewable resources which provide
(a) Habitat, food, protection to wildlife.
(b) Help in balancing CO$ _2$ and O$ _2$ of atmosphere.
(c) Improves water holding capacity of soil.
(d) Regulates water cycle.
(e) For human being, they are the source for all essential commodities like, fuel wood, timber pulp and paper etc.
(f) It provides useful products like fruits, resins, gums, essential oils, bidi wrapper etc. 
Therefore, the correct answer is option D.

When we destroy forest, what we are actually destroying?

  1. Only food for the wild life

  2. Only wild life's habitat

  3. Only trees

  4. Only environment


Correct Option: D
Explanation:

Forests are important for the environment as well as human life.

  1. Half of the earth's oxygen is generated by forests. Thus cutting down forests will cause gradual depletion of oxygen.
  2. Forests support wildlife and are the shelter for these animals. Destroying them will cause death and extinction of these wildlife animals.
  3. The trees absorbs the carbon dioxide generated by industries, transportation and other human activities. Most of the pollution control is brought about by forests.
  4. Forests control floods.
  5. They also help in regulating regional climate.
Thus destroying forests is indirectly destroying the environment.

Forest destruction results in 

  1. Loss of wild life

  2. Famine, floods and drought

  3. Soil erosion

  4. All of the above


Correct Option: D
Explanation:

Deforestation is the cutting of trees which disturbs the equilibrium of a healthy environment. It increases the carbon dioxide content in the atmosphere and contributes to global warming. They produce oxygen and regulates the water cycle by releasing water vapour into the atmosphere. Without trees, forest lands can quickly become barren land. It also causes loss of wildlife, due to the loss of its habitat. Deforestation leads to famine (scarcity of food), flood, and drought as well as loosened soil causes soil erosion. Thus, the correct answer is option D.

If forest cover is reduced to half, what is most likely to happen on a long term basis? 

  1. Tribals living in these areas will starve to death.

  2. Domestic animals in these and joining areas will die due to lack of fodder.

  3. Large biomes will become deserts.

  4. Crop breeding programes will suffer due to a reduced ability of variety of germplasm.


Correct Option: A
Explanation:

If forest cover is reduced to half, it would adversely affect the inhabitants. In rural areas, a community of people lives in the forest as a part of their tradition. They are completely dependent on the forest for their basic needs. They worship the trees and consider it as their ancestral belongings. The dependent tribals on a particular forest will be harmed by the clearing of the forest.

What is not useful to increase agriculture production?

  1. Mechanisation of agriculture

  2. Enhanced irrigation facilities

  3. Use of fertilizers

  4. Deforestation


Correct Option: D
Explanation:

Deforestation is the excessive cutting down of the trees which adversely affects the environment. It is not useful for increasing the agricultural production as because it creates several major problems like soil erosin, infertility, and droughts.

In the recent years, there has been an increasing incidence of floods in the plains of northern India, because

  1. There has been an increase in annual rainfall.

  2. The rate of silting of dams has gone lip.

  3. There has been increased deforestation in the catchment areas.

  4. Increased areas of land is being self cultivated.


Correct Option: C
Explanation:

Deforestation is the removal of forest that can cause flooding. Coastal vegetation reduces the impact of waves and winds associated with a storm surge. Without this vegetation, coastal villages are susceptible to damaging floods. When trees are there, the roots are able to hold the soil and prevent erosion. When the roots are gone after deforestation, the soil can be errode and causes flood or other natural disasters.

Therefore, the correct answer is option C.

What are the advantages of reforestation?

  1. It helps to reduce the concentration of CO$ _2$ in the environment.

  2. It has the potential to preserve endangered species.

  3. It can reverse the damage done by erosion.

  4. All of the above.


Correct Option: D
Explanation:

Deforestation results in an increase in CO$ _2$ concentration in the atmosphere, greenhouse gasses like CO$ _2$ and methane significantly contribute to a changing climate. Reforestation involves the planting of the trees of same species. It is an effective method to reduce CO$ _2$ in the atmosphere, it also helps in restoring habitat loss and also helps in fighting against climate change and help in restoring endangered species from extinction.

Thus, the correct answer is option D.

An ecologist wants to study the impact of habitat fragmentation on a forest ecosystem. Which of these would be the least impactful way to study the potential effect of habitat fragmentation while giving the most useful information? 

  1. Using a computer model to generate possible outcomes

  2. Observing a fragmented prairie ecosystem

  3. Deforesting an ecosystem and observing the effects

  4. Hypothesizing about what might be possible outcomes of fragmentation

  5. Experirmenting on a small patch of trees in a controlled area


Correct Option: B
Explanation:
Effects of habitat fragmentation on forest ecosystem can be best studied in small and isolated populations. Prairie is a kind of dog. Prairie ecosystem is highly fragmented and effects of habitat fragmentation can't be studies easily in such fragmented ecosystems.
So, the correct answer is 'Observing a fragmented prairie ecosystem'.

Which of these is an example of an ecological intervention?

I. Toxic site remediation
II. Large-scale reforestation
III. Introduction of new species

  1. I only

  2. II only

  3. III only

  4. I and III only

  5.  I, II and III


Correct Option: E
Explanation:
Ecological intervention is use of conventional ways to deal with environment emergencies for its protection and conservation.
I. Toxic site remediation is the removal of contaminants and other polluting substances from the site.
II. Large scale reforestation is the plantation of trees for removing pollution from the atmosphere.
III. Introduction of new species to increase the biodiversity is also a conventional way of ecosystem conservation.
So, the correct answer is 'I, II and III'.

Concentration of green house gases is increasing due to

  1. Deforestation

  2. Increased use of refrigerators

  3. Increased combustion of coal and petroleum

  4. All of the above


Correct Option: D
Explanation:

The greenhouse gases are capable of trapping and reflecting the sun's radiations on the earth's surface. Examples include carbon dioxide, methane, nitrous oxides etc. These are naturally released by activities like volcanic eruptions, forest fires, respiration etc. But their increased levels have occurred due to the anthropogenic activities like deforestation, increased use of refrigerators (releasing CFCs) and increased combustion of coal and petroleum (releasing oxides of nitrogen, sulphur and carbon). Because of the increase in their levels, they have caused climate change by global warming.

Hence, the correct answer is 'All of the above'.

A successful forest conservation strategy should involve

  1. protection of animals at the highest trophic level

  2. protection of only sonsumers

  3. protection of only herbivores

  4. comprehensive programme to protect all the physical and biological components


Correct Option: D
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