With reference to the consequences of deforestation, consider the following statements: 1. It leads to an increase in the carbon dioxide level in the atmosphere. 2. It causes an increase in the water holding capacity of the soil. 3. It results in an increase in the infiltration rate of water into the ground. Which of the statements given above is/are correct?

The correct option is (a). Explanation Deforestation refers to the large-scale removal of trees from forests or other lands for the facilitation of human activities. It significantly alters the biogeochemical cycles, particularly the carbon cycle and the hydrological cycle, impacting soil properties and atmospheric composition. Statement-wise Analysis - Statement 1 is Correct: Trees act as natural carbon sinks by absorbing carbon dioxide (CO2) from the atmosphere during photosynthesis. When forests are cleared, this absorption ceases. Furthermore, if the wood is burned or decomposes, the stored carbon is released back into the atmosphere as CO2. Consequently, deforestation is a major contributor to the increase in atmospheric greenhouse gases. - Statement 2 is Incorrect: Trees and their root systems play a crucial role in maintaining soil structure and adding organic matter (humus). Humus significantly increases the water-holding capacity of the soil. Deforestation leads to the loss of organic matter and soil structure, thereby decreasing the soil's ability to retain water. - Statement 3 is Incorrect: Vegetation cover slows down the flow of rainwater over the surface, allowing more time for the water to seep into the ground. Root systems also create channels (macropores) that facilitate water movement. The removal of vegetation accelerates surface runoff and reduces the infiltration rate, often leading to increased soil erosion and flash floods. Key Takeaway: Deforestation disrupts environmental stability by increasing atmospheric carbon dioxide levels and degrading soil hydrological functions, specifically reducing both water-holding capacity and infiltration rates.

With reference to the consequences of… - NCERT Class 8 Environment & Ecology MCQ

NCERT Class 8 Environment & Ecology — Chapter 1: Conservation of plants and animals

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With reference to the consequences of deforestation, consider the following statements:

It leads to an increase in the carbon dioxide level in the atmosphere.
It causes an increase in the water holding capacity of the soil.
It results in an increase in the infiltration rate of water into the ground.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT Science - class 8 · Page 2

Options

A1 only
B2 only
C1 and 3 only
D1, 2 and 3

Did you get this right?

Solution

The correct option is (a).

Explanation

Deforestation refers to the large-scale removal of trees from forests or other lands for the facilitation of human activities. It significantly alters the biogeochemical cycles, particularly the carbon cycle and the hydrological cycle, impacting soil properties and atmospheric composition.

Statement-wise Analysis

Statement 1 is Correct: Trees act as natural carbon sinks by absorbing carbon dioxide (CO₂) from the atmosphere during photosynthesis. When forests are cleared, this absorption ceases. Furthermore, if the wood is burned or decomposes, the stored carbon is released back into the atmosphere as CO₂. Consequently, deforestation is a major contributor to the increase in atmospheric greenhouse gases.
Statement 2 is Incorrect: Trees and their root systems play a crucial role in maintaining soil structure and adding organic matter (humus). Humus significantly increases the water-holding capacity of the soil. Deforestation leads to the loss of organic matter and soil structure, thereby decreasing the soil's ability to retain water.
Statement 3 is Incorrect: Vegetation cover slows down the flow of rainwater over the surface, allowing more time for the water to seep into the ground. Root systems also create channels (macropores) that facilitate water movement. The removal of vegetation accelerates surface runoff and reduces the infiltration rate, often leading to increased soil erosion and flash floods.

Key Takeaway: Deforestation disrupts environmental stability by increasing atmospheric carbon dioxide levels and degrading soil hydrological functions, specifically reducing both water-holding capacity and infiltration rates.

Your note

More from Chapter 1: Conservation of plants and animals

Consider the following statements regarding the impact of deforestation on the environment: 1. It decreases the temperature of the earth. 2. It leads to a change in soil properties and texture. 3. It decreases the chances of natural calamities like floods. Which of the statements given above is/are correct?

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Consider the following statements regarding soil and deforestation: 1. The presence of trees significantly accelerates soil erosion. 2. The humus content in the soil decreases when the top layer is removed. 3. Deforestation generally leads to a decrease in the nutrient content of the soil.

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What is the primary reason for the lowering of the groundwater table in deforested areas?

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