ICSE Class 8 Biology Oxford Chapter 05 Conservation

Conservation

Learning Outcomes

Conservation of natural resources

Balance of nature

Conservation of renewable resources: forests, wildlife, soil, and water

Conservation of non-renewable resources: fossil fuels and mineral deposits

Setting personal goals and practicing methods of conserving energy and materials

Observe Pictures (a) to (c) Carefully and Try to Answer the Following Questions

1. Do you use the things shown in these pictures in your day-to-day life? If so, how?

2. How essential are these things to you?

Anything that is essential for living or which makes our lives easier is called a resource. Thus, we can say that pictures (a) to (c) show different resources. Most of the resources we use in our day-to-day lives (including those shown in these pictures) come from nature, and are called natural resources.

In this chapter we will learn about different types of resources. We will also discuss the impact of human activities on these resources.

Teacher's Note

Help students identify resources in their own homes and understand how they depend on nature for their survival and comfort.

Types of Natural Resources

Natural resources are of two types: renewable and non-renewable.

Renewable resources are those that can replace or renew themselves, if used carefully. All living things (e.g., animals, crops, and forests) belong to this group. Soil and water are also renewable resources.

Non-renewable resources are those that cannot be replaced in the environment after they have been used up. These include coal deposits, oil deposits, natural gas, minerals, and metals.

Humans have been using the resources provided by nature from time immemorial. In ancient times, they had limited needs and lived in perfect harmony with nature. With the development of agriculture, human dependence on natural resources increased. With urbanization and industrialization, coupled with a rapid increase in population, human influence on the environment has been ever increasing. One of the main aspects of human influence on the environment has been the increased demand for natural resources, which has resulted in their overexploitation.

The world we live in is still very rich in natural resources, despite their greedy exploitation in the recent past. Therefore, wise management or conservation of natural resources is the need of the hour.

Teacher's Note

Discuss with students how rapid industrialization and population growth have led to increased pressure on natural resources, making conservation efforts essential.

Conservation of Natural Resources

Conservation is the sensible management of natural resources. It involves the use and preservation of these resources without overexploitation, misuse, or waste.

Conservation of Renewable Resources

Renewable resources such as solar energy, wind, and tidal energy are virtually inexhaustible. Resources such as plants, animals, soil, and water, are said to be 'potentially renewable'. They are renewed, at a fairly rapid rate, through natural processes. This does not mean that they can be exploited indiscriminately. Their proper management is still essential. If they are used at a faster rate than the rate at which nature renews them, they can be lost forever.

Plants and animals, which are also natural resources, often depend on one another. You may already know this from your study of food chains and food webs in lower classes. This interaction between organisms in nature, which produces a stable, continuing system of life, is often termed balance of nature. Thus, in nature, the survival of one species often depends on the survival of another. Human activities can affect a certain species often upset this balance of nature, affecting all organisms which depend on that particular species. Let us consider an example to understand this better.

Suppose there is a forest from where animals cannot move out or move in because of natural barriers. Producers, herbivores (such as deer), and carnivores (such as the tigers) live in harmony and the forest thrives well. Let us say, the deer population is 100 and the tiger population is four. Now imagine a poacher entering this forest and shooting down two tigers. What will be the impact of this event on the forest? With fewer tigers to hunt them, the deer would multiply fast and would soon become numerous enough to eat up all the available vegetation and exhaust it. They would then die of starvation. This example clearly shows how human interference in an ecosystem could upset the balance of nature with disastrous consequences.

Let us consider various aspects concerning the conservation of natural resources such as forests, wildlife, soil, and water.

Forest Conservation

Forests are dominated by trees and plants. They provide shelter to a variety of animals.

Importance

1. Forests provide timber and pulp wood.

2. Roots of trees bind soil particles together (Fig. 5.1) and prevent them from being carried away by wind or water. The loss of fertile top soil by the action of wind, water, etc., is termed soil erosion.

3. Many forest plants have medicinal value.

4. Forests assist in the control of floods, conservation of water supplies, and maintaining water cycles.

Problem: Presently the rate of timber consumption outstrips the rate at which it is replaced. The growing demand for land, mainly for housing and agriculture, has also led to large-scale destruction of forests.

The large-scale destruction of forests is termed deforestation (Fig. 5.2).

Deforestation results in soil erosion. The soil that is carried away tends to block the mouths of rivers, resulting in floods. Forest fires, too, pose a serious threat

Steps for Conservation

1. Forest conservation laws - Realizing the importance of protecting the forests of our country, the Government of India has enacted the Forest (Conservation) Act 1980. The act regulates the use of forest land for non-forest purposes and seeks to check deforestation. The act was amended in 1988 with stricter provisions against violators.

2. Public participation - The concept of social forestry was started in 1976 in India. One of its main objectives was to encourage villagers and schoolchildren to cultivate plants for firewood and fodder and fast-growing timbers, fruit trees, etc., on private land to relieve the pressure on forests.

The chipko movement was started in the Himalayas by the local tribal women in 1972. It gathered momentum in 1978 when these women used a unique way to protect trees from woodcutters - by embracing them (chipko means to embrace) (Fig. 5.3). The movement continued under the leadership of Sunderlal Bahuguna and spread to other parts. Although initially conceived by the illiterate tribal women, the chipko movement questioned developments based on the ruthless exploitation of nature to achieve short-term gains.

3. Afforestation - Afforestation is the process of converting open land into a forest by planting trees (Fig. 5.4). It seeks to compensate for trees lost through deforestation. For every tree cut at least one should be planted - if not more.

Teacher's Note

Discuss the role of community movements like Chipko in raising awareness about forest conservation and how individual actions can contribute to environmental protection.

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