These DAV Class 8 Science Notes and DAV Class 8 Science Chapter 8 Notes – Conservation of Plants and Animals act as excellent revision resources, particularly in preparation for board exams.
Conservation of Plants and Animals Class 8 DAV Notes
→ Deforestation: Indiscriminate cutting of trees in forests is called deforestation.
→ Domestic Consequences of Deforestation:
- Disrupted river flow: Deforestation reduces the rainfall. This affects the flow of rivers and also the path of a river.
- Flooding: Deforestation leads to increased instances of flooding because of lack of trees to bind the soil and absorb water. Deposition of soil in the river bed decreases the depth of rivers.
- Drought: Deforestation results in increased amount of carbon dioxide in the atmosphere. This leads to global warming. Global warming disturbs the water cycle and there is reduced rainfall. All of this leads to droughts.
- Wildlife Extinction: Deforestation results in loss of habitat for many plants and animals. Many species have become extinct or are on the verge of extinction due to this.
- Displacement of forest dwellers: The tribes have lost their home because of deforestation.
- Scarcity of forest produce: Less number of trees means there is scarcity of important forest produce.
→ Global Consequences of Deforestation:
Climate Change: Global warming has resulted in dramatic shift in climatic patterns across the world. The summers are becoming hotter and rainfall is deficient in many parts of the world.
Desertification: Trees hold the topsoil with their roots. Deforestation has made the soil naked and is a major cause of soil erosion. Soil erosion finally leads to desertification, i.e. formation of deserts.
Ozone Depletion: Some greenhouse gases destroy the ozone layer. Due to which it is, getting depleted.
→ Conservation of Wildlife and Forests
→ Ecosystem: A natural unit consisting of all biotic and abiotic factors in an area is called ecosystem.
→ Species: A group of organisms that can interbreed to produce fertile offsprings is called species.
→ Conservation: The protection, preservation, management or restoration of wildlife resources is known as conservation.
→ Biodiversity: The variety of organism on earth is called biodiversity.
Conserving biodiversity is very important because a group of organisms has an important role to play in an ecosystem.
→ Biosphere Reserve: A biosphere reserve is an international conservation designation given by UNESCO under its Programme on Man and Biosphere (MAB). The World Network of Biosphere Reserves is the collection of all 533 biosphere reserves in 107 countries. The government of India has established 17 Biosphere reserves of India.
Four of the fifteen biosphere reserves of India are part of the World Network of Biosphere Reserves as per UNESCO.
These are: Nilgiri Biosphere Reserve, Nanda Devi Biosphere Reserve, Sundarbans Biosphere Reserve and Gulf of Mannar Biosphere Reserve.
→ National Parks: A national park is a reserve of land which is usually declared and owned by the national government. It is protected from most human development and pollution. The Jim Corbett National Park was the first National Park in India established in 1935.
Kaziranga National Park has two-thirds of the world’s great one-horned rhinoceros population. Bandipur National Park is an important reserve for Project Tiger.
→ Wildlife Sanctuaries: A wildlife sanctuary is an officially designated territory, which provides protection and sustainable living conditions for wild animals. Hunting, killing or capturing of animals is strictly prohibited in such areas. There are over 440 wildlife sanctuaries in India.
→ Flora: All plant life occurring in an area or time period comprises the flora.
→ Fauna: All animal life occurring in an area or time period comprises the fauna.
→ Endangered Species: Species which faces a high risk of extinction is called endangered species.
→ Vulnerable Species: Species which face a high risk of extinction in the medium term is called vulnerable species.
→ Endemic Species: Species unique to a particular geographical region is called endemic species, e.g. Lion tailed macaque are endemic species of the Western Ghats.
→ Causes of Extinction:
- Loss of Habitat: Deforestation or dramatic alteration of environment can lead to loss of habitat for a species.
- Overexploitation: Hunting of an animal for meat and for other animal parts leads to overexploitation of that animal.
- Introduced Species: Introduction of new species can have a significant effect on an endemic species; because of competition for resources.
- Ecosystem Disruption: All organisms in an ecosystem are interlinked. Extinction of any organism can disturb the food chain and as a result, can disturb the whole ecosystem.
→ Red Data Book:
The IUCN (International Union for the Conservation of Nature and Natural Resources) maintains an international list of animals and plants who come under the endangered category. This list is published in the form of Red Data Book. Each Red Data Book deals with a specific group of animals or plants, e.g. reptiles, insects, mosses, etc. Different countries also publish their own version of Red Data Book.
→ Migration: The periodic movement of a species of animals or birds to a far off location to avoid harsh climatic conditions in its natural habitat is called migration. Siberian cranes migrate from Siberia to north-western part of India during every winter.
→ Reforestation: The process of restoring lost forest by planting more and more of trees is called reforestation or afforestation.
→ Recycling of Paper: Paper recycling is the process of recovering useful paper or remaking new paper from waste paper. Paper recycling helps in saving trees and other resources.
→ Deforestation : Indiscriminate cutting of trees to clear forest to make way for human activities is called deforestation.
→ Soil Erosion : Removal of topsoil is called soil erosion.
→ Soil conservation : Prevention of soil erosion.
→ Conservation : Proper management and protection of any wildlife resource is called conservation.
→ Extinct species : A species which no longer exists on the earth.
→ Endangered species : A species which is at risk of extinction in near future.
→ Vulnerable species : A species which ¡s at risk of extinction in medium term.
→ Endemic species : A species unique to a particular geographical area.