Class 8 Science Notes Chapter 7 (Chapter 7) – Examplar Problems Book
Alright class, let's focus on Chapter 7, 'Conservation of Plants and Animals' from your Science Exemplar book. This is a crucial chapter, not just for your exams but also for understanding our environment. Many questions in government exams touch upon environmental issues, biodiversity, and conservation efforts, making this chapter very important. Pay close attention to the definitions and examples.
Chapter 7: Conservation of Plants and Animals - Detailed Notes
1. Introduction: The Problem of Deforestation
- Deforestation: The clearing of forests and using that land for other purposes. It signifies the large-scale removal of trees.
- Causes of Deforestation:
- Man-made:
- Procuring land for cultivation (agriculture).
- Building houses, factories, and infrastructure (roads, dams).
- Making furniture or using wood as fuel.
- Mining activities.
- Natural:
- Forest fires.
- Severe droughts.
- Man-made:
- Consequences of Deforestation:
- Increased Temperature and Pollution Level: Trees absorb CO2 (a greenhouse gas). Fewer trees mean more CO2 in the atmosphere, leading to global warming.
- Lowering of Ground Water Level: Trees help in water percolation. Deforestation disrupts the water cycle.
- Disturbance in Nature's Balance: Loss of habitat for wildlife, impacting the entire ecosystem.
- Soil Erosion: Tree roots bind the soil. Without trees, topsoil gets easily removed by wind or water, reducing soil fertility.
- Desertification: Fertile land gets converted into deserts due to soil erosion and loss of fertility.
- Decreased Water Holding Capacity of Soil: Leads to increased chances of floods.
- Loss of Biodiversity: Destruction of habitats leads to a decline in the variety of plant and animal life.
2. Biodiversity: The Variety of Life
- Biodiversity (Biological Diversity): Refers to the variety of living organisms existing on the Earth, their interrelationships, and their relationship with the environment. It includes plants, animals, and microorganisms.
- Flora: Refers to all the different kinds of plants found in a particular area. Example: Sal, Teak, Mango, Jamun found in the Pachmarhi Biosphere Reserve.
- Fauna: Refers to all the different kinds of animals found in a particular area. Example: Chinkara, Blue-bull, Barking deer, Cheetal, Leopard, Wild dog, Wolf found in the Pachmarhi Biosphere Reserve.
- Endemic Species: Those species of plants and animals that are found exclusively in a particular geographical area and not naturally anywhere else.
- They are vulnerable to extinction due to habitat loss or introduction of new species.
- Examples: Sal and Wild Mango are endemic flora of the Pachmarhi Biosphere Reserve. Bison, Indian Giant Squirrel, and Flying Squirrel are endemic fauna of this area.
- Species: A group of populations which are capable of interbreeding. Members of a species can reproduce fertile offspring only with members of their own species.
- Extinct Species: Species of plants or animals that no longer exist anywhere on Earth. Example: Dodo, Dinosaurs.
- Endangered Species: Animal species whose numbers are diminishing to a level that they might face extinction if the causal factors continue. Survival is difficult. Examples: Tiger, Snow Leopard, Great Indian Bustard, Asiatic Lion.
- Vulnerable Species: Species likely to become endangered unless the circumstances threatening their survival and reproduction improve.
3. Conservation of Forest and Wildlife: Protecting Our Natural Heritage
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Need for Conservation: To protect biodiversity, maintain ecological balance, preserve genetic diversity, and ensure the availability of resources for future generations.
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Protected Areas: Areas designated to protect and maintain biological diversity, along with natural and associated cultural resources.
- Wildlife Sanctuary: Areas where animals are protected from any disturbance to them and their habitat. Killing (poaching) or capturing animals is strictly prohibited. Limited human activities like grazing or collecting firewood may be permitted without harming wildlife. Example: Bori Sanctuary (part of Pachmarhi Biosphere Reserve).
- National Park: Areas reserved for wildlife where they can freely use the habitats and natural resources. They provide stricter protection than sanctuaries. Activities like grazing, forestry, cultivation, etc., are not permitted. Example: Satpura National Park (First Reserve Forest of India, finest Indian teak found here).
- Biosphere Reserve: Large areas of protected land for conservation of wildlife, plant and animal resources, and the traditional life of the tribal people living in the area. They aim to conserve the biodiversity and culture of that area. A biosphere reserve may contain other protected areas within it (e.g., National Parks, Sanctuaries). Example: Pachmarhi Biosphere Reserve (contains Satpura National Park and Bori & Pachmarhi Wildlife Sanctuaries).
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Ecosystem: Consists of all the living components (plants, animals, microorganisms) in an area along with the non-living components (climate, soil, river deltas, etc.).
4. Specific Conservation Efforts & Records
- Project Tiger: A wildlife conservation project launched by the Government of India in 1973 to protect tigers in India. It aimed to ensure a viable population of Bengal tigers in their natural habitats and save them from extinction. Satpura Tiger Reserve is an example under this project.
- Red Data Book: The source book which keeps an international record of all endangered animals and plants. Different books exist for plants, animals, and other species. It helps in identifying species at risk and planning conservation strategies. IUCN (International Union for Conservation of Nature) maintains this globally.
5. Migration
- Migration: The seasonal, periodic movement of animals (especially birds) in large numbers from one place to another to overcome unfavourable climatic conditions, for breeding, or in search of food.
- Migratory Birds: Birds that fly to far away areas every year during a particular time due to climatic changes. Example: Siberian Crane travels thousands of kilometers to places like Bharatpur in India during winter.
6. Solutions: Recycling and Reforestation
- Recycling of Paper: Paper is made from wood pulp (trees). Recycling paper saves trees, energy, and water used in manufacturing paper. It also reduces harmful chemicals used in papermaking. It takes about 17 full-grown trees to make one tonne of paper.
- Reforestation: Restocking of destroyed forests by planting new trees.
- Ideally, the species planted should be the same as those that were originally found in that forest.
- Can happen naturally if the deforested area is left undisturbed.
- Essential for restoring green wealth, habitats, and ecological balance.
- Afforestation: Planting trees in an area where there were no forests previously.
Key Takeaways for Exams:
- Know the precise definitions of: Deforestation, Biodiversity, Flora, Fauna, Endemic Species, Endangered Species, Extinct Species, Wildlife Sanctuary, National Park, Biosphere Reserve, Migration, Reforestation.
- Remember specific examples, especially those mentioned for Pachmarhi Biosphere Reserve (Sal, Wild Mango, Giant Squirrel, Flying Squirrel) and endangered species (Tiger).
- Understand the differences between Sanctuary, National Park, and Biosphere Reserve (level of protection, scope).
- Know the purpose of Project Tiger and the Red Data Book.
- Understand the causes and severe consequences of deforestation.
- Recognize the importance of recycling paper and reforestation.
Multiple Choice Questions (MCQs)
Here are 10 MCQs based on the chapter concepts for your practice:
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Which of the following is a major natural cause of deforestation?
a) Building houses
b) Forest fires
c) Procuring land for cultivation
d) Making furniture -
The conversion of fertile land into deserts is known as:
a) Soil Erosion
b) Reforestation
c) Desertification
d) Migration -
Species of plants and animals found exclusively in a particular area are termed:
a) Endangered species
b) Extinct species
c) Migratory species
d) Endemic species -
The Red Data Book provides a list of:
a) Endemic species only
b) Extinct species only
c) Endangered plants and animals
d) Flora and fauna of a National Park -
Which protected area offers the strictest level of protection where wildlife can freely use habitats and natural resources, and human activities like grazing are generally not permitted?
a) Wildlife Sanctuary
b) Biosphere Reserve
c) National Park
d) Reserve Forest -
Project Tiger was launched primarily to:
a) Count the number of tigers
b) Protect tigers from extinction
c) Create more wildlife sanctuaries
d) Study the migration of tigers -
Sal and Wild Mango found in the Pachmarhi Biosphere Reserve are examples of:
a) Endemic Flora
b) Endemic Fauna
c) Endangered Species
d) Extinct Species -
The seasonal movement of birds like the Siberian Crane from colder regions to warmer regions for breeding is called:
a) Hibernation
b) Aestivation
c) Migration
d) Adaptation -
Restocking destroyed forests by planting new trees, preferably of the same species, is known as:
a) Deforestation
b) Afforestation
c) Reforestation
d) Desertification -
Which of the following is a significant consequence of deforestation leading to climate change?
a) Increase in groundwater level
b) Decrease in soil erosion
c) Increase in atmospheric Carbon Dioxide (CO2)
d) Increase in biodiversity
Answer Key:
- b) Forest fires
- c) Desertification
- d) Endemic species
- c) Endangered plants and animals
- c) National Park
- b) Protect tigers from extinction
- a) Endemic Flora
- c) Migration
- c) Reforestation
- c) Increase in atmospheric Carbon Dioxide (CO2)
Study these notes thoroughly. Remember the definitions, examples, and the purpose behind conservation efforts. Good luck with your preparation!