NCERT Class 8 Science Curiosity Chapter 12 How Nature Works in Harmony PDF Download

Chapter 12: How Nature Works in Harmony

In several parts of India, particularly in states like Odisha, Jharkhand, West Bengal, Assam, and Chhattisgarh, elephants often enter farms and villages. When vegetation is scarce and waterholes dry up in their natural habitat, elephants may wander into nearby farms or plantations in search of food like bananas and sugarcane. This can lead to crop damage and at times, even harm people and domestic animals.

Changes in rainfall and temperature affect vegetation. Cutting down trees for constructing roads and buildings makes it worse. This leads to the drying and shrinking of forests, the natural home of animals. Because of loss of habitat, animals tend to move into human habitats. Elephants are adapted to forest life, but sudden changes make it hard for them to survive. Wildlife ecologists have identified and marked corridors in many parts of the country to allow safe movement of animals. These corridors connect forest habitats, enabling wildlife - such as elephants to travel in need between large forest areas without coming into conflict with human settlements.

This chain of events shows how closely nature's elements are connected. To understand such interconnections, we must study the components of our environment.

12.1 How Do We Experience and Interpret Our Surroundings?

You have learnt in Curiosity, Grade 6 chapter 'Diversity in the Living World' that different habitats have different kinds of plants and animals. A habitat is simply place where an organism lives. It could even be just the bark of a tree. The plants and animals interact with each other and adapt to survive in the surrounding conditions they live in. Explore two nearby habitats and identify both the living organisms and the non-living components in each.

Activity 12.1: Let us explore

Caution: Explore the habitat in groups with your teacher.

• Identify two habitats in your surroundings.
• These could be any two of the following: a pond, a forest, an agricultural farm, or even a large tree like banyan, mango, or pilkhan (white fig) tree.
• List the living beings and non-living things that you observe in these habitats.
• Record your observations in Table 12.1.

[Figure 12.1: Two types of habitats, See in your textbook]

What common characteristics do you observe in the two habitats in Activity 12.1? The similarities are that both habitats have living beings as well as non-living things. However, the types of living beings are different and the non-living things also vary. The living beings you have recorded in Table 12.1 are termed as the biotic components and non-living things as the abiotic components of a habitat. Have you wondered why some organisms live on land while others live in water? Every organism needs specific conditions to survive. From this activity, you can see that different habitats offer different living conditions.

Teacher's Note

Do not confuse biotic and abiotic. Biotic means anything living - plants, animals, fungi, bacteria. Abiotic means non-living - water, soil, air, sunlight, temperature. A quick way to remember: abiotic has an 'a' at the start, like "absent of life". In exams, when asked to classify components, make sure you think about whether it was once alive and can grow or reproduce.

In Activity 12.1, you listed fish as a biotic component of the pond. How do fish survive in a pond? A pond provides food, oxygen, shelter, and space to grow - conditions essential for survival of organisms. Fish obtain their biotic needs, such as food, from small plants and animals, and abiotic needs, such as oxygen, from water.

Other living beings also inhabit the pond, such as frogs, turtles, snakes, dragonflies, mosquitos, snails, and ducks, along with plants like algae, diatoms, duckweeds, and lotus. They all interact with the other living beings and non-living things present in the places where they grow and thrive.

Teacher's Note

Notice that every organism in the pond depends on both other living things and the non-living environment. For example, a fish needs oxygen from water (abiotic), small animals for food (biotic), and shelter among plants (biotic). This web of dependence is what the chapter is building toward. When you answer questions about "why organisms live where they do", always think about what they need from both categories.

Key Points

• A habitat is a place where an organism lives, and every habitat has both living things (biotic components) and non-living things (abiotic components).
• Different organisms need different conditions to survive, which is why different habitats have different types of plants and animals.
• When humans destroy forests or change the environment through activities like cutting trees or building roads, animals lose their habitats and may move into human settlements.
• Wildlife corridors are protected pathways that allow animals like elephants to move safely between forest areas without coming into conflict with human communities.
• All organisms depend on both living beings and non-living things in their habitat to meet their needs for food, oxygen, water, shelter, and space.

This is a preview of the first 3 pages. To get the complete chapter, click below.