Forests : Our Lifeline

NCERT Solutions for Class 7 Science Chapter 12

Forests are far more than just scenic landscapes. They are the Earth’s lungs, playing a vital role in sustaining life and deserve the title “Our Lifeline.” The chapter Forests our lifeline delves deeper into the numerous ways forests contribute to our well-being:

1. Clean Air Providers:

• Trees act as natural air filters. They absorb carbon dioxide (CO2), a gas we exhale and a greenhouse gas, and release oxygen (O2) through photosynthesis, the process by which they use sunlight to create food. This fresh O2 is essential for respiration in humans and animals.
• Forests help combat air pollution by trapping dust particles and harmful gases on their leaves.

2. Water Cycle Regulators:

• Forests play a crucial role in managing the water cycle. Their extensive root systems hold soil particles together, preventing soil erosion caused by heavy rainfall.
• They act like giant sponges, absorbing rainwater and slowly releasing it back into the ground. This replenishes groundwater reserves, a source of clean drinking water for humans and ecosystems.
• Forests also help regulate stream flow by reducing the force of raindrops hitting the ground and minimizing flash floods.

3. Biodiversity Treasure Troves:

• Forests are teeming with life, serving as homes to a vast array of plants and animals. This rich biodiversity includes countless species of trees, shrubs, herbs, insects, birds, mammals, and even microorganisms.
• Each species plays a specific role in the forest ecosystem, creating a complex web of interdependencies. Plants provide food and shelter for animals, while animals help disperse seeds, ensuring forest regeneration.

4. Climate Control Champions:

• Forests act as natural air conditioners, helping to regulate Earth’s temperature. Trees provide shade, reducing the impact of direct sunlight on the ground and keeping the surrounding air cooler.
• Through transpiration, the process by which plants release water vapor into the atmosphere, forests contribute to increased humidity and cloud formation, further influencing temperatures.
• Additionally, forests absorb carbon dioxide, a greenhouse gas that traps heat from the sun, thereby mitigating the effects of global warming.

5. Resource Bounty:

• Forests are a treasure trove of natural resources that benefit humanity in numerous ways.
  • Timber from trees is used for construction, furniture, and paper production.
  • We obtain various fruits, nuts, and food items from forest plants.
  • Many medicinal plants with healing properties grow in forests.
  • Forests provide raw materials for various industries like rubber, bamboo, and essential oils.

6. Soil Protectors:

• The network of tree roots acts as a natural barrier against soil erosion. They bind soil particles together, preventing them from being washed away by wind and heavy rainfall.
• This fertile topsoil is crucial for agriculture, allowing us to grow crops that sustain our food systems.

Beyond these benefits, the chapter might have covered:

• Different types of forests (tropical rainforests, temperate deciduous forests, coniferous forests) and their unique characteristics.
• The detrimental effects of deforestation, such as loss of biodiversity, increased soil erosion, and disruption of the water cycle.
• The importance of forest conservation and sustainable practices to protect these vital ecosystems.
• Simple actions we can take to preserve forests, such as planting trees, reducing paper consumption, and supporting sustainable forestry initiatives.

NCERT Solutions for Class 7 Science Chapter 12

Exercises

1. Explain how animals dwelling in the forest help it grow and regenerate.

Ans : Forest animals act like seed-spreading gardeners (birds, squirrels), pollinators (bees, butterflies) and nutrient recyclers (through droppings). They also keep plant-eating animals in check, promoting overall forest health.

2. Explain how forests prevent floods.

Ans : Forests are flood fighters! They soak up rainwater like a sponge (absorption), release it slowly (regulation), and hold soil in place with roots (preventing erosion). This reduces the risk of overflowing rivers and flash floods.

3. What are decomposers? Name any two of them. What do they do in the forest?

Ans : Decomposers are forest cleanup crew (bacteria, fungi). They break down dead plants and animals, releasing nutrients back into the soil for plants to use. This keeps nutrients cycling and helps create fertile soil.

4. Explain the role of forest in maintaining the balance between oxygen and carbon dioxide in the atmosphere.

Ans : Forests act like Earth’s lungs! They take in CO2, used by plants for food, and release fresh O2, which we breathe. This two-way breathing helps balance these gases in the air.

5. Explain why there is no waste in a forest.

Ans : Forests are recycling champions! Dead plants and animals feed decomposers, which release nutrients for new plant growth.  This loop uses everything and creates almost no waste.

6. List five products we get from forests.

Ans : 

1. Timber: Used for construction (furniture, houses), paper production, and other wood products.
2. Non-timber forest products: Fruits, nuts, mushrooms, medicinal plants, and other natural resources.
3. Clean Air: Forests absorb carbon dioxide and release oxygen, vital for respiration.
4. Clean Water: Forests help regulate water flow and prevent erosion, leading to cleaner water sources.
5. Biodiversity: Forests provide habitat for countless plants and animals, promoting a rich and diverse ecosystem.

7.Fill in the blank:

(a) The insects, butterflies, honeybees and birds help flowering plants in .

(b) A forest is a purifier of and .

(c) Herbs form the layer in the forest.

(d) The decaying leaves and animal droppings in a forest enrich the .

Ans : 

(a) pollination 

(b) water, air 

(c) lowest 

(d) soil as humus.

8. Why should we worry about the conditions and issues related to forests far from us?

Ans : Faraway forests matter! They impact us all because they:

• Fight climate change by absorbing CO2 (global warming gas).
• Protect wildlife (habitat loss hurts everyone).
• Regulate water (floods & droughts).
• Provide resources (timber, food, medicine).
• Clean the air (we all breathe!).

9. Explain why there is a need of variety of animals and plants in a forest.

Ans : Many plants and animals in a forest are like a well-balanced team! Here’s why variety matters:

• Food chain: Keeps everyone fed (herbivores eat plants, carnivores eat herbivores, decomposers clean up).
• Happy homes: Variety creates different habitats for different creatures.
• Nutrient recycling: More decomposers means better break down of dead things, providing nutrients for plants.
• Plant love: Variety of pollinators helps plants reproduce.
• Stronger together: A diverse forest can better handle challenges.

10. In fig. 1 7.15 the artist has forgotten to put the labels and directions on the arrows. Mark the directions on the arrows and label the diagram using the following labels: clouds, rain, atmosphere, cabon dioxide, oxygen, plants, animals, soil, roots, water table.

Ans : 

11.Which of the following is not a forest product?

(i) Gum (ii) Plywood (iii) Sealing wax (iv) Kerosene

Ans : (iv) Kerosene.

12.Which of the following statements is not correct?

(i) Forests protect the soil from erosion.

(ii) Plants and animals in a forest are not dependent on one another.

(iii) Forests influence the climate and water cycle.

(iu) Soil helps forests to grow and regenerate.

Ans : (ii) Plants and animals in a forest are not dependent on one another.

13.Micro-organisms act upon the dead plants to produce

(i) sand (ii) mushrooms (iii) humus (iu) wood

Ans : (iii) humus.

NCERT Solutions for Class 7 Science Chapter 12

FAQ’s

What are the different types of forests discussed in Chapter Forests Our lifeline?

Chapter Forests our lifeline discusses various types of forests, including tropical forests, temperate forests, and mangrove forests, highlighting their unique characteristics and ecological significance.

How can NCERT Solutions for class 7science Chapter 12 help me understand the significance of forests?

NCERT Solutions provide detailed explanations and examples that elucidate the importance of forests as the lifeline of our planet. By studying these solutions, you can grasp the vital role forests play in sustaining life on Earth.

What are the main threats to forests discussed in Chapter Forests our lifeline?

Chapter forests our lifeline explores various threats to forests, such as deforestation, illegal logging, habitat destruction, forest fires, and invasive species, emphasizing the need for forest conservation and sustainable management practices.

How can individuals contribute to forest conservation efforts?

Individuals can contribute to forest conservation efforts by planting trees, participating in reforestation and afforestation projects, reducing their carbon footprint, supporting sustainable forestry practices, and raising awareness about the importance of forests.

What are the economic benefits of forests discussed in Chapter Forests our lifeline?

Chapter forests our lifeline highlights the economic benefits of forests, including timber production, non-timber forest products, ecotourism, and carbon trading, underscoring the importance of sustainable forest management for long-term economic prosperity.