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Conservation of Biodiversity - Deforestation and its Consequences

Grade 8CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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Deforestation is the clearing of forests and using the land for other purposes such as industries, agriculture, or housing.

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Major causes of deforestation include procuring land for cultivation, building houses and factories, and using wood as fuel or making furniture.

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Consequences of deforestation include an increase in temperature and pollution levels on earth due to the accumulation of greenhouse gases like CO2CO_2.

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Plants use CO2CO_2 for photosynthesis. Fewer trees mean more CO2CO_2 remains in the atmosphere, trapping heat rays reflected by the earth, leading to Global Warming.

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Deforestation leads to a decrease in the water-holding capacity of the soil and affects the movement of water from the soil surface into the ground (infiltration rate).

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The removal of the top layer of soil exposes the lower, hard, and rocky layers. This soil has less humus and is less fertile, leading to a process called desertification.

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Loss of forest cover results in the loss of natural habitats for various species, leading to a decline in biodiversity.

📐Formulae

6CO2+6H2O→ChlorophyllSunlightC6H12O6+6O26CO_2 + 6H_2O \xrightarrow[\text{Chlorophyll}]{\text{Sunlight}} C_6H_{12}O_6 + 6O_2

Infiltration Rate∝Forest Cover\text{Infiltration Rate} \propto \text{Forest Cover}

↑[CO2]  ⟹  ↑Atmospheric Temperature (Global Warming)\uparrow [CO_2] \implies \uparrow \text{Atmospheric Temperature (Global Warming)}

💡Examples

Problem 1:

Explain how deforestation leads to a decrease in rainfall.

Solution:

Deforestation reduces the number of trees, which in turn reduces the amount of water vapor released into the atmosphere through the process of transpiration. Since there is less water vapor to form clouds, the frequency and amount of rainfall decrease, potentially leading to droughts.

Explanation:

Trees are a vital part of the water cycle; fewer trees mean less atmospheric moisture and disrupted precipitation patterns.

Problem 2:

Why does the concentration of CO2CO_2 increase in the atmosphere when forests are cut down?

Solution:

Plants require CO2CO_2 for the process of photosynthesis represented by the equation 6CO2+6H2O→C6H12O6+6O26CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2. When trees are cut down, the number of organisms capable of absorbing CO2CO_2 decreases, causing the gas to accumulate in the atmosphere.

Explanation:

Photosynthesis acts as a natural carbon sink. Removal of trees eliminates this sink, leading to higher levels of CO2CO_2 and an enhanced greenhouse effect.