Get summaries, questions, answers, solutions, notes, extras, PDF and guide of Chapter 4 Impact of Ecosystem Destruction, NBSE Class 9 Environmental Education textbook, which is part of the syllabus of students studying under Nagaland Board. These solutions, however, should only be treated as references and can be modified/changed.
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Summary
Ecosystem destruction means the environment is getting damaged. This happens when natural resources like water, air, and soil are used up too much. When this balance is disturbed, it can be very bad for all living things that depend on it. The effects of ecosystem destruction include more flooding because there are fewer trees and soil is washed away. Climate change causes sea levels to rise as glaciers melt. Natural disasters like tsunamis, earthquakes, and droughts may become more common. When top predators disappear, the food chain gets disrupted. Fresh drinking water becomes scarce, and food shortages happen when land becomes barren and oceans lose fish. Biodiversity is lost when entire species vanish due to deforestation. Pollution becomes hard to manage and harms human health. Rising temperatures can be unbearable for living organisms.
Habitats are places where animals live, grow, and reproduce. Forests are important habitats for many animals. Some animals live in rocks or tree bark. Human activities like mining, cutting forests, building dams, and using pesticides destroy these habitats. Deforestation is a big reason why habitats are lost. Forest fires also ruin habitats. Urbanization destroys habitats on land, water, and trees. Many animals have to move or may even die out.
Many plant and animal species are dying at an alarming rate. Between 4000 to 50,000 species go extinct every year. Tropical rainforests and coral reefs are the richest ecosystems but are being destroyed. If this continues, tropical rainforests might disappear by 2030. The Great Hornbill and other hornbill species are becoming rare. Reasons include deforestation, farming methods like Jhum cultivation, hunting, illegal wildlife trade, lack of awareness, and climate changes. Endangered species are those at risk of extinction. About 34,000 plant species and 5200 animal species are endangered. Habitat loss, pollution, and overuse are major causes. Extinct species are those that have vanished from Earth. Extinction has increased due to human population growth and resource use. This affects the food chain and the ecosystem.
Stress on resources happens when there is too much demand on a system or resource. As the human population grows, resources fall short. Consumption is higher in developed countries compared to developing ones. Controlling population and consumption is necessary. Resources are depleting fast. For example, the Mesabi Range in the USA was rich in iron ore but started running out by the 1950s. More people mean more need for wood, leading to harmful tree-cutting practices. This makes soil erode and destroys habitats. Groundwater levels dropping can cause problems like methemoglobinemia, where nitrates affect blood’s oxygen-carrying ability. Certain activities should be stopped to protect groundwater. Cleaning parks and planting trees are good ways to help the environment.
Textbook solutions
Multiple Choice Questions (MCQs)
1. This is the main or major activity of destruction of habitat
A. Afforestation
B. Habitat
C. Deforestation
D. Flood
Answer: C. Deforestation
2. Species that are in the danger of extinction are called:
A. Extinct
B. Endangered
C. Rare
D. None of these
Answer: B. Endangered
3. Species that disappeared from the earth are called:
A. Extinct
B. Endangered
C. Rare
D. None of these
Answer: A. Extinct
4. Major cause for the extinction of domestic animals is:
A. Hunting
B. Diseases
C. Food scarcity
D. None of these
Answer: B. Diseases
5. An endangered mammal from India:
A. Panda
B. Cheetah
C. Gorilla
D. Whale
Answer: B. Cheetah
Very Short Answer Questions
1. Define habitat.
Answer: A habitat of an organism is the place where it can live, develop, and reproduce. Forest is the main habitat of many animals. Some animals live in the crevices of rocks or in the bark of trees.
2. What do you mean by stress on resources?
Answer: Stress on resources can be defined as a difficult situation that arises when a system or resource is expected to do too much. As the human population grows, the resources fall short because resources are limited and the human population does not stop growing. Therefore, the consumption of resources keeps on increasing.
Short Answer Questions
1. What are endangered species? Write is the cause of endangerment of species?
Answer: Plant and animal species that are in the danger of extinction are called endangered species.
The chief cause for the endangerment of species is habitat destruction, besides pollution and commercial exploitation.
2. What are extinct species? Give one reason for the extinction of species.
Answer: Species that have disappeared from Earth are called extinct species. One reason for the extinction of species is that many natural habitats are being destroyed.
3. Why does the consumption of resources keep on increasing?
Answer: The consumption of resources keeps on increasing because the human population grows, and resources fall short since they are limited. As a result, the consumption of resources continues to rise. Additionally, per capita consumption of resources is much higher in developed countries than in developing countries.
4. How human is responsible for environment degradation?
Answer: Human activities are responsible for environmental degradation through the destruction of ecosystems, which causes adverse impacts on habitats. These activities include heavy mining, clearing of forests, construction of dams, modern agricultural practices involving pesticides and insecticides, deforestation, urbanization, and overexploitation of resources. Additionally, stress on resources arises due to growing human population and increasing per capita consumption, leading to the exhaustion of natural resources like water, air, and soil. Overhunting, poaching, illegal wildlife trade, and habitat destruction further contribute to the endangerment and extinction of species.
Long Answer Questions
1. Give reasons for the loss of habitat. What is the immediate threat of loss of habitat?
Answer: The reasons for the loss of habitat are:
- Heavy mining, clearing of forests, and construction of dams, which cause many animals to migrate or even become extinct.
- Modern agricultural practices, including the use of pesticides and insecticides, which cause heavy destruction of habitats.
- Deforestation, which is the main or major activity of habitat destruction.
- Forest fires, which lead to the destruction of habitats.
- Urbanisation, which destroys numerous habitats of organisms on land, water, and trees.
The immediate threat of habitat loss is that it causes animals to become homeless, disrupts their ability to live, develop, and reproduce, and leads to the migration or extinction of many species.
2. Why do resources of an ecosystem face stress from mankind?
Answer: Resources of an ecosystem face stress from mankind due to the following reasons:
- The number of people is more in developing countries and less in developed countries, but the per capita consumption of resources is much higher in developed countries than in developing countries.
- The growing human population and increasing per capita consumption lead to a higher rate of exhaustion of resources, causing them to deplete faster.
- As the population increases, the demand for wood, a major building material, also increases.
- Clear cutting techniques of felling trees, where all trees in an area are removed abruptly, make the soil naked and lead to excessive erosion.
- Habitat destruction is another impact of this technique, further stressing the ecosystem’s resources.
3. Write a note on stress on resources.
Answer: Stress on resources can be defined as a difficult situation that arises when a system or resource is expected to do too much. As the human population grows, the resources fall short because resources are limited, and the human population does not stop growing. Therefore, the consumption of resources keeps on increasing.
- The number of people is more in developing countries and less in developed countries. However, the per capita consumption of resources is much higher in developed countries than in developing countries.
- The strategy should not only focus on controlling the population but also on controlling the per capita consumption of resources.
- As a result of the growing human population and increasing per capita consumption, the rate of exhaustion of resources is also increasing, leading to the fast depletion of resources.
- With the increase in population, the demand for wood also increases because it is a major building material.
- The clear-cutting technique of felling trees, where all the trees of an area are removed abruptly, is very harmful. It makes the soil naked, leading to excessive erosion and habitat destruction.
Extras
Additional questions and answers
1. What is meant by environmental degradation?
Answer: Environmental degradation is the deterioration of the environment caused by the exhaustion of natural resources including water, air, and soil.
21. Outline the role of human consumption patterns in the rapid depletion of natural resources.
Answer: Human consumption patterns play a significant role in the rapid depletion of natural resources. As the human population grows, the resources fall short because resources are limited, and human population does not stop growing. Therefore, the consumption of resources keeps on increasing.
(i) The number of people is more in developing countries and less in developed countries. However, the per capita consumption of resources is much higher in developed countries than in developing countries.
(ii) The strategy should not only be to control the population but also to control the per capita consumption of resources.
(iii) As a result of growing human population and increasing per capita consumption, the rate of exhaustion of resources is also increasing, leading to the fast depletion of resources.
Additional MCQs
1. What impact results from the erosion of soil and lack of trees?
A. Flooding
B. Drought
C. Famine
D. Landslide
Answer: A. Flooding
39. What effect does urbanisation have on natural habitats?
A. Expansion
B. Preservation
C. Destruction
D. Restoration
Answer: C. Destruction
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