All questions of Terrestrial Ecosystems for BPSC (Bihar) Exam

Consider the following statements about the Indian desert - Thar Desert:
1. The climate of this region is characterized by excessive drought, the rainfall being scanty and irregular.
2. The winter rains of northern India rarely penetrate the region.
Which of these statements is/are incorrect?
  • a)
    1 Only
  • b)
    2 Only
  • c)
    Both 1 and 2
  • d)
    Neither 1 nor 2
Correct answer is option 'D'. Can you explain this answer?

Mira Sharma answered
Thar desert: The climate of this region is characterized by excessive drought, the rainfall being scanty and irregular.
The winter rains of northern India rarely penetrate the region. The relative humidity of the atmosphere is always low. The climate is hostile to all vegetation, only plants and animals possessing special adaptations being able to establish themselves.
 
 

Consider the following statements about the Tundra region:
1. They are found where environmental conditions are very severe.
2. On the South Pole, tundra is very small since most of it is covered by the ocean.
3. Mammals of the tundra region have a large body size, long tail and large ear.
Which of these statements is/ are correct?
  • a)
    1 and 2 Only
  • b)
    2 and 3 Only
  • c)
    1 and 3 Only
  • d)
    All of the above
Correct answer is option 'A'. Can you explain this answer?

Tundra Region

The Tundra region is a cold, treeless region found in the Arctic and subarctic regions of the world. Let's analyze the given statements about the Tundra region.

Statement 1: They are found where environmental conditions are very severe.
This statement is true. The Tundra region is characterized by severe environmental conditions such as low temperatures, strong winds, and short growing seasons. The region is covered by permanently frozen soil called permafrost, which makes it difficult for plants to grow.

Statement 2: On the South Pole, tundra is very small since most of it is covered by the ocean.
This statement is also true. The South Pole is mostly covered by the Antarctic ice sheet, which is a polar desert. The small areas of ice-free land in Antarctica are mostly rocky and barren, with very little vegetation. Therefore, the Tundra region is small in the South Pole.

Statement 3: Mammals of the tundra region have a large body size, long tail, and large ear.
This statement is false. Mammals in the Tundra region have adapted to survive in the harsh environmental conditions. Many mammals in the Tundra region have a small body size, thick fur, and a layer of insulating fat to keep them warm. They also have short ears and tails to prevent heat loss.

Conclusion

From the above analysis, we can conclude that only statements 1 and 2 are correct. Statement 3 is false. Therefore, the correct answer is option 'A'.

Consider the following statements about the Shifting Cultivation:
1. In this practice, a patch of land is cleared, vegetation is burned and the ash is mixed with the soil.
2. This patch of land is used for raising crops for two to three years, and the yield is modest.
Which of these statements are correct?
  • a)
    1 Only
  • b)
    Both of them
  • c)
    2 Only
  • d)
    Neither 1 nor 2
Correct answer is option 'B'. Can you explain this answer?

Ojasvi Mehta answered
  • In this practice a patch of land is cleared, vegetation is burned and the ash is mixed with the soil thus adding nutrients to the soil.
  • This patch of land is used for raising crops for two to three years, and the yield is modest. Then this area is abandoned and is left to recover its fertility, and the same practice is repeated elsewhere on a fresh piece of land.
 
 
 

Forests influence the water cycle primarily through which process?
  • a)
    Evaporation
  • b)
    Transpiration
  • c)
    Condensation
  • d)
    Precipitation
Correct answer is option 'B'. Can you explain this answer?

Mehul Shah answered
Understanding the Role of Forests in the Water Cycle
Forests play a crucial role in the water cycle, with transpiration being a key process through which they influence this natural system.

What is Transpiration?
- Transpiration is the process by which water is absorbed by plant roots from the soil, moves through plants, and is released as water vapor through small openings called stomata in leaves.

How Transpiration Influences the Water Cycle
- **Water Vapor Release**: Through transpiration, forests release significant amounts of water vapor into the atmosphere, which contributes to humidity levels.
- **Cloud Formation**: The water vapor released can condense to form clouds, which is a critical step in the precipitation process.
- **Precipitation Enhancement**: Increased humidity from transpiration can lead to more rainfall, benefiting not only forests but also surrounding ecosystems and agriculture.

Additional Benefits of Transpiration
- **Microclimate Regulation**: Transpiration helps regulate temperatures in forested areas, creating a cooler microclimate that can influence local weather patterns.
- **Soil Moisture Retention**: By contributing to atmospheric moisture, transpiration indirectly helps maintain soil moisture levels, which is vital for plant growth and ecosystem stability.

Conclusion
In summary, while evaporation, condensation, and precipitation are also important processes in the water cycle, transpiration stands out as the primary mechanism through which forests influence this cycle. The release of water vapor by trees not only affects local climates but also plays a vital role in the global water cycle.

Assertion (A): Afforestation in desert regions is necessary to prevent desertification.
Reason (R): Trees help in changing the climate and meeting the local needs for firewood, timber, and fodder.
  • a)
    Both A and R are true, and R is the correct explanation of A
  • b)
    Both A and R are true, but R is not the correct explanation of A
  • c)
    A is true, but R is false
  • d)
    A is false, and R is true
Correct answer is option 'A'. Can you explain this answer?

Anjana Dey answered
Assertion:
Afforestation in desert regions is necessary to prevent desertification.

Reason:
Trees help in changing the climate and meeting the local needs for firewood, timber, and fodder.

Explanation:
- Afforestation in desert regions is essential to prevent desertification as trees play a crucial role in stabilizing soil, reducing soil erosion, and increasing water retention in arid areas.
- Trees also help in changing the local climate by providing shade, reducing temperatures, and increasing humidity levels, which can contribute to preventing further desertification.
- Additionally, trees serve as a sustainable source of firewood, timber, and fodder for local communities living in desert regions, thereby reducing their dependence on scarce natural resources and preventing overexploitation of the environment.
Therefore, both the assertion and reason are true, and the reason correctly explains why afforestation in desert regions is necessary to prevent desertification.

In the context of desertification, what role does increased agriculture play?
  • a)
    It decreases soil erosion
  • b)
    It disrupts natural ecosystems and increases aridity
  • c)
    It enhances water retention in soil
  • d)
    It has no significant impact on desertification
Correct answer is option 'B'. Can you explain this answer?

Rahul Menon answered
Increased Agriculture and Desertification
In the context of desertification, increased agriculture significantly impacts the environment, primarily by disrupting natural ecosystems and increasing aridity. Here's how:
Land Use Changes
- Expansion of agricultural land often leads to the conversion of forests and grasslands into croplands.
- This transformation reduces biodiversity and alters the natural habitat, which is essential for maintaining ecological balance.
Soil Degradation
- Intensive farming practices can lead to soil compaction and loss of soil structure.
- The use of chemical fertilizers and pesticides can deplete essential nutrients, further degrading soil quality and its ability to retain moisture.
Water Resources Strain
- Agriculture consumes a significant amount of water, often leading to the depletion of local water sources.
- Over-irrigation can result in salinization, making the soil less fertile and contributing to arid conditions.
Increased Erosion
- The removal of vegetation for agricultural purposes exposes the soil to wind and water erosion.
- This can lead to the loss of the fertile topsoil, making areas more susceptible to desertification.
Climate Impact
- Agricultural activities can contribute to climate change through greenhouse gas emissions.
- Changes in land cover and land use can alter local climates, potentially increasing aridity and reinforcing desertification processes.
In summary, while agriculture is essential for food production, its expansion often disrupts natural ecosystems, leading to increased aridity and contributing to the desertification process. Sustainable agricultural practices are crucial to mitigate these effects.

Consider the following statements regarding the animals of the desert ecosystem:
1. They are fast runners.
2. They are nocturnal in habit to avoid the sun’s heat during day time.
3. They conserve water by excreting concentrated urine.
Which of these statements is/are correct?
  • a)
    1 and 2 Only
  • b)
    2 and 3 Only
  • c)
    1 and 3 Only
  • d)
    All of the above
Correct answer is option 'D'. Can you explain this answer?

Pooja Shah answered
The animals are physiologically and behaviorally adapted to desert conditions. They are fast runners, they are nocturnal in habit to avoid the sun’s heat during day time, they conserve water by excreting concentrated urine, animals and birds usually have long legs to keep the body away from the hot ground.

Consider the following statements regarding Grasslands:
1. Typical grasslands are vegetation formations that are generally found in temperate climates
2. In India, they are found everywhere except the high Himalayas.
Which of these statements is/are correct?
  • a)
    1 Only
  • b)
    2 Only
  • c)
    Both 1 and 2
  • d)
    Neither 1 nor 2
Correct answer is option 'A'. Can you explain this answer?

Ojasvi Mehta answered
  • The grasslands are found where rainfall is about 25-75 cm per year, not enough to support a forest, but more than that of a true desert.
  • Typical grasslands are vegetation formations that are generally found in temperate climates. In India, they are found mainly in the high Himalayas.

Consider the following statements:
1. It covers the Ganga alluvial plain in Northern India
2. The topography is level, low lying and ill-drained
These statements are best related with:
  • a)
    Dry sub humid zone
  • b)
    Semi-arid zone
  • c)
    Moist sub humid zone
  • d)
    Humid montane regions
Correct answer is option 'C'. Can you explain this answer?

Ojasvi Mehta answered
  • Semi-arid zone: It covers the northern portion of Gujarat, Rajasthan (excluding Aravallis), western Uttar Pradesh, Delhi and Punjab. The topography is broken up by hill spurs and dunes.
  • Dry sub-humid zone: It covers the whole of peninsular India (except Nilgiri).
  • Moist sub-humid zone: It covers the Ganga alluvial plain in Northern India. The topography is level, low lying and ill-drained.
  • Humid montane regions: This extends to the humid montane regions and moist sub-humid areas of Assam, Manipur, West Bengal, Uttar Pradesh, Punjab, Himachal Pradesh and Jammu and Kashmir. The savanna is derived from the humid forests on account of shifting cultivation and sheep grazing.

Consider the following statements:
1. Montane wet temperate forests are found in the region to the east of Nepal into Arunachal Pradesh.
2. In the South, it is found in parts of the Nilgiri Hills.
3. The forests in the northern region are denser than in the South.
Which of these statements is/are correct?
  • a)
    1 and 2 Only
  • b)
    2 and 3 Only
  • c)
    1 and 3
  • d)
    All of the above
Correct answer is option 'D'. Can you explain this answer?

**Explanation:**

The correct answer is option D: All of the above.

1. Montane wet temperate forests are found in the region to the east of Nepal into Arunachal Pradesh:
- Montane wet temperate forests are a type of forest that is found in the higher altitudes of the Himalayan region.
- These forests are characterized by cool and moist conditions, with a high amount of rainfall.
- They are typically found at elevations between 2,000 and 3,500 meters.
- The region to the east of Nepal, extending into Arunachal Pradesh, is known for its montane wet temperate forests.
- Therefore, statement 1 is correct.

2. In the South, it is found in parts of the Nilgiri Hills:
- The Nilgiri Hills are located in the southern part of India, primarily in the states of Tamil Nadu and Kerala.
- These hills are known for their rich biodiversity and are home to various types of forests, including montane wet temperate forests.
- The montane wet temperate forests in the Nilgiri Hills are found at higher elevations where the climate is cooler and there is a higher amount of rainfall.
- Therefore, statement 2 is correct.

3. The forests in the northern region are denser than in the South:
- Montane wet temperate forests in the northern region, such as in the eastern Himalayas, are known to be dense and have a higher tree density compared to the forests in the southern region, such as the Nilgiri Hills.
- This is primarily due to the differences in climate and altitude between the two regions.
- The northern region receives more rainfall and has a cooler climate, which supports the growth of dense forests.
- Therefore, statement 3 is correct.

In conclusion, all of the given statements are correct. Montane wet temperate forests are found in the region to the east of Nepal into Arunachal Pradesh, as well as in parts of the Nilgiri Hills in the South. The forests in the northern region are denser than in the South.

What is the main environmental impact of development projects like large dams and reservoirs?
  • a)
    Promotion of biodiversity
  • b)
    Reduction in carbon footprint
  • c)
    Extensive deforestation
  • d)
    Improvement in soil quality
Correct answer is option 'C'. Can you explain this answer?

Sharmila Datta answered
The main environmental impact of development projects like large dams and reservoirs is extensive deforestation.

Deforestation:
Large dams and reservoirs require vast amounts of land for construction. This often involves clearing large areas of forests to make way for the project. The removal of trees and vegetation leads to deforestation, which has several negative consequences for the environment.

Loss of Biodiversity:
Deforestation caused by the construction of large dams and reservoirs results in the loss of habitat for numerous plant and animal species. Forests are incredibly diverse ecosystems, home to a wide range of flora and fauna. When forests are cleared, many species lose their homes and are unable to survive. This loss of biodiversity can have far-reaching ecological consequences.

Disruption of Ecosystems:
Forests play a crucial role in maintaining ecological balance. They help regulate temperature, provide oxygen, absorb carbon dioxide, and contribute to the water cycle. Deforestation disrupts these important ecosystem services, leading to imbalances and negative impacts on the environment.

Soil Erosion:
One of the direct consequences of deforestation is soil erosion. The removal of trees and vegetation leaves the soil exposed to erosion by wind and water. Without tree roots to hold the soil in place, it can easily be washed away or blown away. This erosion degrades soil quality and can lead to decreased agricultural productivity in the long term.

Loss of Carbon Sink:
Forests act as carbon sinks, absorbing carbon dioxide from the atmosphere and storing it in trees and soil. When forests are cleared, this carbon is released back into the atmosphere, contributing to greenhouse gas emissions and climate change.

Conclusion:
While development projects like large dams and reservoirs can bring economic benefits and meet the growing energy and water demands of a population, it is important to consider the environmental impacts. Extensive deforestation caused by these projects has significant negative consequences for biodiversity, ecosystems, soil quality, and climate change. Therefore, it is essential to implement sustainable practices and mitigate the environmental impacts associated with such development projects.

Consider the following statements about the impact of grazing:
1. Due to heavy grazing pressure, the quality of grasslands deteriorates rapidly, the mulch cover of the soil reduces.
2. Due to the absence of humus cover, the mineral soil surface is heavily trampled, when wet it produces puddling of the surface layer.
Which of these statements is/are incorrect?
  • a)
    1 Only
  • b)
    2 Only
  • c)
    Both 1 and 2
  • d)
    Neither 1 nor 2
Correct answer is option 'D'. Can you explain this answer?

Lakshmi Chavan answered
Impact of Grazing

The impact of grazing on grasslands and soil can be significant. Let's look at the given statements and analyze their accuracy.

Statement 1: Due to heavy grazing pressure, the quality of grasslands deteriorates rapidly, the mulch cover of the soil reduces.

This statement is true. Grazing animals can have a significant impact on grasslands. When there are too many animals grazing in an area, they can quickly consume all the vegetation and leave the soil exposed. This can lead to erosion and a reduction in the quality of the grasslands.

Statement 2: Due to the absence of humus cover, the mineral soil surface is heavily trampled, when wet it produces puddling of the surface layer.

This statement is also true. When animals graze in an area, they can trample the soil and create compacted areas. This can make it difficult for plants to grow and for water to penetrate the soil. In addition, when the soil is wet, animal hooves can create puddles on the surface, further damaging the soil.

Conclusion

Both statements are accurate and describe the impact of grazing on grasslands and soil. Therefore, the correct answer is option 'D' - Neither 1 nor 2.

Consider the following statements about the Temperate evergreen forest:
1. These are commonly inhabited by low broad-leaved evergreen trees
2. Fire is an important hazardous factor in this ecosystem and the adaptation of the plants enable them to regenerate quickly after being burnt
Which of these statements is/are correct?
  • a)
    1 Only
  • b)
    2 Only
  • c)
    Both 1 and 2
  • d)
    Neither 1 nor 2
Correct answer is option 'C'. Can you explain this answer?

Deepa Iyer answered
Temperate evergreen forest:
  • Parts of the world that have the Mediterranean type of climate are characterised by warm, dry summers and cool, moist winters.
  • These are commonly inhabited by low broad-leaved evergreen trees.
  • Fire is an important hazardous factor in this ecosystem and the adaptation of the plants enables them to regenerate quickly after being burnt.
 
 
 

Consider the following statements about the desertification:
1. It is the destruction of the biological potential of the land which can ultimately lead to desert-like conditions.
2. In arid and semiarid regions, the restoration of the fragile ecosystem is very slow, and issues like deforestation, mining enhances desertification.
Which of these statements are correct?
  • a)
    1 Only
  • b)
    2 Only
  • c)
    Both 1 and 2
  • d)
    Neither 1 nor 2
Correct answer is option 'C'. Can you explain this answer?

Deepa Iyer answered
  • It is the destruction of the biological potential of the land which can ultimately lead to desert-like conditions.
  • In arid and semiarid regions, the restoration of the fragile ecosystem is very slow, and issues like deforestation, mining enhances desertification.
  • Desertification is the main problem faced by desert adjoining areas, which stretches across parts of Rajasthan, Gujarat, Punjab and Haryana.

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