Chapter 2 - Land, Soil, Water, Natural Vegetation and Wildlife Resources Notes
1. Land• It covers only about 30% of the total area of the Earth's surface.
• Uneven distribution of population due to varied topography climate.
• Land is used for agriculture, forestry, mining, building and setting up of industries. This is termed as land use.
• The use of land is determined by physical factors such as topography, soil, climate, minerals and water availability.
• Human factors such as population and technology are also important determinants.
• Land can also be classified as private and community land.
• These community land are also called common property land.
2. Land Degradation
Causes of land degradation are as follows:
• Deforestation
• Landslides
• Soil erosion
• Desertification
• Overgrazing
3. Land Conservation
Land can be conserved by the following measures:
• Afforestation
• Land reclamation
• Regulated use of chemical fertilizers and pesticides.
• Checks on overgrazing.
4. Soil
• The thin layer of grainy substance covering the surface of the earth is called soil.
• Soil is made of organic matter, minerals and weathered rocks found on the Earth.
• The right mixture of minerals and organic matter make the soil fertile.
• Weathering is the breaking up and decay of exposed rocks, temperature changes, frost, plants, animals and human activity.
• In India soils could be alluvial, black, red, laterite, desertic and mountain soil.
5. Soil formation
• Parent rock - Determines color, texture, chemical properties, mineral, content, permeability.
• Relief - Altitude and slope, determine accumulation of soil
• Flora, Fauna and Microorganisms - Affect the rate of humus formation
• Time - Determines thickness of soil profile
• Climate - Temperature, rainfall influence, rate of weathering and humus formation
6. Soil degradation
• Soil erosion and depletion are major threats to soil as a resource.
• Soil erosion is caused by natural factors as well as human factors.
• The natural factors include deforestation, landslides and floods.
• Human factors include deforestation, overgrazing and overuse of chemical fertilizers and pesticides.
7. Soil conservation measures
• Mulching
• Contour Barriers
• Rock dams
• Terrace farming
• Intercropping
• Contour ploughing
• Shelter belts
8. Mulching - The bare ground between plants is covered with a layer of organic matter like straw. It helps to retain soil moisture.
9. Contour Barriers - Stones, grass, soil are used to build barriers along contours. Trenches are made in front of barriers to collect water.
10. Rock dam - Rocks are piled up to slow down the flow of the water. This prevent gullies and further soil loss.
11. Terrace farming - Broad flat steps or terraces are made on the steep slopes so that the flat surfaces are available to grow crops. They reduce surface run-off and soil erosion.
12. Intercropping - Different crops are grown in alternate rows and are sown at different times to protect the soil from rainwash.
13. Contour ploughing - Ploughing in parallel to the contours of a hill slope to form a natural barrier for water to flow down the slope.
14. Shelter belts - In the coastal and dry regions, rows of trees are planted to check the wind movement to protect the soil cover.
15. Water
• It is a vital renewable natural resource.
• The oceans cover nearly two-thirds of earth's surface but the water is saline and not fit for human consumption.
• Out of 2.7% of fresh water only 1% of fresh water is available and fit for human use.
• Water is used for drinking, washing, agriculture, generating electricity cleaning etc.
16. Problems of water availability
• Increasing population
• Rising demand for food and cash crops
• Increasing urbanisation
• Water pollution
• Discharge of partially treated sewage
• Agricultural chemicals discharge in water bodies
17. Water Conservation
• Treatment of industrial waste before releasing them in water bodies.
• Rain water harvesting
• Use of sprinklers
• Drip or trickle irrigation
• Canals should be lined to avoid seepage
18. Natural Vegetation and Wildlife
• Natural vegetation and wildlife only exists in Biosphere.
• The entire part of earth's land, soil, water & atmosphere in which living organism are found is called biosphere.
19. Innumerable Uses of plants
• Shelters to animals, protects soil, produces oxygen
• Given fruits, nuts, latex, gum, timber, medical plants
• Helps in storage of underground water
• Acts as shelter belts
20. Bounties from Wildlife
• Milk, meat, hides and wool
• Decomposers
• Scavengers-vital cleanser of the environment
• Maintain the balance of the eco-system
21.
22. Reasons for extinction
Forests are our wealth. They give shelters to animals and together maintain ecosystem. But humans and natural factors can cause the loss of natural habitats.
• Soil erosion
• Construction activities
• Forest fires
• Tsunami
• Landslides
• Poaching
23. Ninety per cent of the world population occupies only thirty per cent of land area. The remaining seventy per cent of the land is either sparsely populated or uninhabited.
24. It takes hundreds of years to make just one centimetre of soil.
25. In 1975, the consumption of water for human use was 3850cu km/year. It soared to more than 6000cu km/year in the year 2000.
26. A dripping tap wastes 1200 litres of water in a year.
27. Amreli city in Saurastra region with a population of 1.25 lakhs is completely dependent on purchasing water from the nearby talukas.
28. Rain water harvesting is the process of collecting rain water from roof tops and directing it to an appropriate location where it is stored for future use. On an average, one spell of rain for two hours is enough to save 8,000 litres of water.
29. Vultures in the Indian subcontinent were dying of kidney failure shortly after scavenging livestock treated with diclofenac, a painkiller that is similar to aspirin or ibuprofen.
30. National Park is a natural area designated to protect the ecological integrity of one or more ecosystems for the present and the future generations.
31. Biosphere reserves is a series of protected areas linked through a global network, intended to demonstrate the relationship between conservation and development.
32. CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) is an international agreement between governments. It aims to ensure that international trade in specimens of wild animals and plants does not threaten their survival. Roughly 5,000 species of animals and 28,000 species of plants are protected. Bears, dolphins, cacti, corals, orchids and aloes are some examples.
23. Ninety per cent of the world population occupies only thirty per cent of land area. The remaining seventy per cent of the land is either sparsely populated or uninhabited.
24. It takes hundreds of years to make just one centimetre of soil.
25. In 1975, the consumption of water for human use was 3850cu km/year. It soared to more than 6000cu km/year in the year 2000.
26. A dripping tap wastes 1200 litres of water in a year.
27. Amreli city in Saurastra region with a population of 1.25 lakhs is completely dependent on purchasing water from the nearby talukas.
28. Rain water harvesting is the process of collecting rain water from roof tops and directing it to an appropriate location where it is stored for future use. On an average, one spell of rain for two hours is enough to save 8,000 litres of water.
29. Vultures in the Indian subcontinent were dying of kidney failure shortly after scavenging livestock treated with diclofenac, a painkiller that is similar to aspirin or ibuprofen.
30. National Park is a natural area designated to protect the ecological integrity of one or more ecosystems for the present and the future generations.
31. Biosphere reserves is a series of protected areas linked through a global network, intended to demonstrate the relationship between conservation and development.
32. CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) is an international agreement between governments. It aims to ensure that international trade in specimens of wild animals and plants does not threaten their survival. Roughly 5,000 species of animals and 28,000 species of plants are protected. Bears, dolphins, cacti, corals, orchids and aloes are some examples.
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