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In NCERT Class 7 Science Chapter 12, we will explore the significance of forests. In this learning process, we will discover the role of forests as lungs of the planet Earth, warehouse of flora and fauna, home to tribes, the natural reservoir of water, and source of useful products. All these have been laid down in simple words in our CBSE Science notes. In addition, we will learn about deforestation and its consequences. Furthermore, our subject experts have also provided answers to writing questions in this lesson. Have fun learning!!
Download NCERT Solutions Class 7 Science Chapter 12 Important Questions and Answers PDF
Explore all the Chapters of Class 7 Science:
| Chapter 1 | Chapter 2 | Chapter 3 | Chapter 4 | Chapter 5 | Chapter 6 |
| Chapter 7 | Chapter 8 | Chapter 9 | Chapter 10 | Chapter 11 | Chapter 12 |
| Chapter 13 |
Also Read: Largest Forests in the World
Table of Contents
Forest Our Lifeline Class 7 Notes
Let us now explore Class 7 Science Chapter 12 notes.
Importance of Forests
NCERT Class 7 Science Chapter 12 focuses on the importance of forests. In this lesson, we will learn about the role of forests and greenery in our environment and the planet Earth.
Forests: Lungs of Planet Earth
Forests are home to a wide range of plants. These plants inhale carbon dioxide and exhale oxygen during photosynthesis. Oxygen exhaled by plants is used for the respiration of animals. In addition, the exchange of gases during photosynthesis also maintains the balance of oxygen and carbon dioxide in the atmosphere. Due to these reasons, forests are known as the lungs of the planet Earth.
Forests: Home to Flora and Fauna
Forests are home to several plants, insects, and animals.
| Trees | Animals | Insects |
| Sal; Teak; Semal; Shesham; Neem; Palash; Fig; Khair; Amla; Bamboo; Kachnar | Bison; Jackals; Porcupine; Elephants; Squirrels | Ants; Spiders; Beetles; Grubs |
Forests: Home to Tribes
In addition, forests are home to various tribes. These tribes or the original inhabitants of forests depend on forests for their daily needs. Forests provide the original inhabitants with shelter, water, food, and medicines. As tribal people know the forest best, they have abundant knowledge about medicinal plants in their surroundings.
Forest: A Dynamic Living Entity
Furthermore, the forest’s rich diversity of plant species creates more abundant food and habitat options for herbivores. A higher population of herbivores results in greater food resources for various carnivores. This wide array of animal species contributes to the regeneration and growth of the forest ecosystem. Decomposers play a vital role in ensuring a continuous supply of nutrients for the growing plants in the forest. As a result, the forest can be described as a dynamic and vibrant living entity, teeming with life and vitality.
Forest: Natural Absorber of Rainwater
Forests serve as natural reservoirs for rainwater, allowing it to permeate the ground. Also, they help in the maintenance of the water table year-round. They play a vital role in flood control and ensure a consistent flow of water in streams, ensuring a steady water supply.
On the other hand, in the absence of trees, rainfall directly hits the ground, potentially causing flooding in the surrounding areas. Heavy rain can also lead to soil damage. Tree roots typically help bind the soil together, but without them, the soil is vulnerable to erosion and washing away.
Forest: Source of Useful Products
As forests are home to numerous trees, herbs, shrubs, creepers, and climbers, they serve as sources of products like timber and medicines. Some of the common items that can be made from forest flora include fuel, plywood, furniture, paper, boxes, medicines, and matchsticks. Also, we get fodder for animals and spices from forests.
In addition, trees in forests produce ample seeds that find favourable conditions on the forest floor to germinate and grow. Thus, the development of seedlings to saplings and then to trees makes forests the source of many useful products.
Read More: Forest Society and Colonialism Class 9 – Study Notes
Deforestation
The intentional destruction of forest areas is known as deforestation. Some of the common causes of deforestation are:
- Agricultural expansion
- Infrastructure expansion
- Wood harvest
- Excessive animal grazing
- Mining
Impact of Deforestation
Here are the consequences of deforestation or depletion of forest area:
- If we lose our forests, there will be more carbon dioxide in the air, which will make the Earth get hotter.
- Without trees and plants, animals will not have enough food and places to live.
- When there are no trees, the ground will be unable to keep water, and that can lead to floods.
Explore: Forest and Wildlife Resources Class 10 Notes
Important Concepts in NCERT Class 7 Science Chapter 12: Forests: Our Lifeline
Let us now dive into important definitions and key concepts in NCERT Class 7 Science Chapter 12.
Crown of the Tree
The branchy part of a tree above its stem is called the “crown of the tree.”
Canopy
The branches of tall trees in forests form a roof-like structure over shorter trees and plants. This roof-like structure is known as a canopy.
Understoreys
The forest contains various types and sizes of tree canopies, resulting in distinct horizontal layers known as “understoreys”. The uppermost layer consists of massive and towering trees, followed by shrubs and tall grasses, and the lowest layer is made up of herbs.
Food Chain
Green plants play a crucial role in food production within ecosystems. All animals, regardless of whether they are herbivores or carnivores, ultimately rely on plants as their primary source of sustenance. Organisms that consume plants are often preyed upon by other organisms, creating a complex web of interactions. For instance, insects feed on grass, and in turn, they are consumed by frogs. Frogs, in their turn, become food for snakes, which may be preyed upon by eagles. These interconnected relationships are known as a “food chain”.
For example: Grass ➔ Insects ➔ Frogs ➔ Snakes ➔ Eagles.
In a forest, numerous food chains coexist, and they are all interconnected. Any disruption in one food chain can change others. The entire forest ecosystem is interdependent, and if one component, like trees, were to be removed, it would have negative consequences for the entire ecosystem.
Humus
The forest soil hosts a variety of organisms, including both larger organisms and microorganisms. These inhabitants of the soil consume dead plant and animal matter and transform it into a dark, organic material known as “humus”.
Decomposers
“Decomposers” are the microorganisms responsible for breaking down and converting dead plants and animals into humus.
Read More: National Forest Martyrs Day 2023: Our Green Guardians
Explore all the Chapters of Class 7 Science:
| Chapter 1 | Chapter 2 | Chapter 3 | Chapter 4 | Chapter 5 | Chapter 6 |
| Chapter 7 | Chapter 8 | Chapter 9 | Chapter 10 | Chapter 11 | Chapter 12 |
| Chapter 13 |
NCERT Solutions Class 7 Science Chapter 12: Forests: Our Lifeline
Ques 1. Explain how animals dwelling in the forest help it grow and regenerate.
Ans: Here are some ways in which forest-dwelling animals help forests grow and regenerate:
- Animals aid in spreading plant seeds.
- The decomposition of animal dung supplies essential nutrients that help plants thrive.
- Microorganisms transform deceased plants and animals into humus, enriching the soil.
Ques 2. Explain how forests prevent floods.
Ans: Plants in the forest act as a shield, preventing rainwater from directly hitting the ground. They also store water, which helps to prevent floods.
Ques 3. What are decomposers? Name any two of them. What do they do in the forest?
Ans: “Decomposers” are the microorganisms responsible for breaking down and converting dead plants and animals into humus.
Common examples of decomposers are bacteria and fungi. They assist in the recycling of nutrients by breaking down and decomposing dead plants and animals.
Ques 4. Explain the role of forests in maintaining the balance between oxygen and carbon dioxide in the atmosphere.
Ans: Forests are home to a wide range of plants. These plants inhale carbon dioxide and exhale oxygen during photosynthesis.
- Oxygen exhaled by plants is used for the respiration of animals.
- In addition, the exchange of gases during photosynthesis also maintains the balance of oxygen and carbon dioxide in the atmosphere.
Ques 5. Explain why there is no waste in a forest.
Ans: In a forest, there is no waste because the waste produced is biodegradable. Microorganisms play a role in turning this waste into humus through their actions.
Ques 6. List five products we get from forests.
Ans: Here are the five products we get from forests:
- Timber
- Spices
- Medicines
- Oil
- Gum
Ques 7. Fill in the blanks:
a. The insects, butterflies, honeybees and birds help flowering plants in_______________.
b. A forest is a purifier of_______________ and __________________.
c. Herbs from the______________ layer in the forest.
d. The decaying leaves and animal droppings in a forest enrich the____________________.
Ans:
a. Pollination
b. Air and Water
c. Lowest
d. Soil
Ques 8. Why should we worry about the conditions and issues related to forests far from us?
Ans: We should worry about the conditions and issues related to forests far from us because the depletion of forests might lead to the following consequences:
- There will be more carbon dioxide in the air, which will make the Earth get hotter.
- Animals will not have enough food and places to live.
- The ground will be unable to keep water, and that can lead to floods.
Ques 9. Explain why there is a need for a variety of animals and plants in a forest.
Ans: The diverse array of plants and animals in forests plays a crucial role in supporting plant regeneration and growth. The wide range of plant species provides food and habitat for herbivores, which, in turn, become prey for carnivores. Decomposers play their part by transforming deceased plants and animals into humus, ensuring the recycling of nutrients. This great diversity makes the forest a dynamic and vibrant living ecosystem.
Ques 11. Which of the following is not a forest product?
(i) Gum
(ii) Plywood
(iii) Sealing wax
(iv) Kerosene
Ans: Option (iv) Kerosene
Ques 12. Which of the following statements is incorrect?
(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.
(iv) Soil helps forests to grow and regenerate.
Ans: Option (ii) Plants and animals in a forest are not dependent on one another.
Ques 13. Micro-organisms act upon the dead plants to produce
(i) Sand
(ii) Mushrooms
(iii) Humus
(iv) Wood
Ans: Option (iii) Humus
Also Read: CBSE Class 9 Natural Vegetation and Wildlife Notes
Also Read:
FAQs
Ans: The intentional destruction of forest areas is known as “deforestation”.
Ans: A series of animals dependent on each other for nutrition is termed the “food chain”.
Ans: The forest soil hosts a variety of organisms, including both larger organisms and microorganisms. These inhabitants of the soil consume dead plant and animal matter and transform it into a dark, organic material known as “humus”.
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