JAC Board Class 8th Social Science Notes Geography Chapter 2 Land, Soil, Water, Natural Vegetation and Wildlife Resources
→ Mamba and Peter stay in two different parts of the world and lead very different lives. This difference is because of the differences in the quality of land, soil, water, natural vegetation, animals and the usage of technology. The availability of such resources is the main reason places differ from each other.
→ Land:
- One of the most important natural resources is Land.
- Land covers only about thirty per cent of the total area of the earth’s surface and all parts of this small area are not habitable.
- Due to varied characteristics of land and climate there is uneven distribution of population in different parts of the world.
- Plains and river valleys are suitable land for agriculture. Hence, these are the densely populated areas of the world.
→ Land Use:
- Land is used for different causes and purposes such as agriculture, forestry, mining, building houses, roads and setting up of industries.
- Certain physical factors such as topography, soil, climate, minerals and availability of water determines the use of land.
- Other important determinants of land use pattern are human factors such as population and technology.
- Land can be divided into two categories on the basis of ownership as – private land and community land.
- Private land is owned by individuals and community land is owned by the community for common uses like collection of fodder, fruits, nuts or medicinal herbs. The community lands are also known as common property resources.
- The major threats to the environment because of the expansion of agriculture and construction activities and proceedings are land degradation, landslides, soil erosion, and desertification.
→ Conservation of Land Resource:
The common methods used to conserve land resources are afforestation, land reclamation, regulated use of chemical pesticide and fertilisers and checks on overgrazing land.
→ Soil:
- Soil is the thin layer of grainy substance covering the surface of the earth and it is very closely linked to land.
- Category of soil is determined the landforms.
- Organic matter, minerals and weathered rocks found on the earth forms the soil.
- The right mix of minerals and organic matter make the soil fertile.
→ Factors of Soil Formation:
The nature of the parent rock and climatic factors are the major factors of soil formation. The topography, role of organic material and time taken for the composition of soil formation are the other factors. Though they all differ from place to place.
→ Degradation of Soil and Conservation Measures:
- The major threats to soil are soil erosion and depletion.
- Soil degradation happens due to deforestation, overgrazing, overuse of chemical feritilisers or pesticides, rain wash, landslides and floods.
→ Few methods of soil conservation are:
- Mulching: The bare ground between plants is covered with a layer of organic matter like straw and it helps to retain soil moisture.
- Contour barriers: Along contours, stones, grass, soil are used to build barriers. To collect water, trenches are made in front of the barriers.
- Rock dam: Rocks are piled up to slow down the flow of water and it prevents gullies and further soil loss.
- Terrace farming: Terraces or broad flat steps are made on the steep slopes so that flat surfaces are available to grow crops. This reduce the surface runoff and soil erosion.
- Intercropping: Different types of crops are grown in alternate rows and are sown at different times to protect the soil from rain wash.
- Contour ploughing: To form a natural barrier, ploughing is done parallel to the contours of a hill slope for water to flow down the slope.
- Shelter belts: Mainly in the coastal and dry regions, rows of trees are planted to check the wind movement to protect soil cover.
→ Water:
- Earth is also known as an ‘water planet’ because three-fourths of the earth’s surface is covered with water.
- The ocean water is not fit for human consumption as it is saline.
- Fresh water accounts for only about 2.7 per cent. In this 2.7 per cent, about 70 per cent of this occurs as ice sheets and glaciers in Antarctica, Greenland and mountain regions and these are inaccessible due to their locations.
- Only 1 per cent of freshwater is available and fit for human use. It is found in the form of ground water, as surface water in rivers and lakes and as water vapour in the atmosphere.
- The most precious substance on earth is fresh water. Its total volume remains constant.
- Humans use huge amounts of water for drinking, washing but also in the process of production.
- The main reasons leading to shortages in supply of fresh water is either due to drying up of water sources or water pollution.
→ Problems of Water Availability:
- Scarcity of water is present in many regions of the world. Mostly countries located in climatic zones are most susceptible to droughts, face great problems of water scarcity.
- Water shortage may be a result of variation in seasonal or annual precipitation or by over-exploitation and contamination of water sources.
→ Conservation of Water Resources:
- World is facing a major problem in accessing the clean and adequate water sources.
- To conserve this valuable resource, steps need to be taken.
- The major contaminants in waterbodies are the discharge of untreated or partially treated sewage, agricultural chemicals and industrial effluents and pollute water with nitrates, metals and pesticides.
- Water pollution can be controlled by treating these effluents suitably before releasing them in waterbodies.
- Another method to save surface runoff is water harvesting.
- Drip or trickle irrigation is very useful in dry regions with high rates of evaporation.
→ Natural Vegetation and Wildlife:
- Natural vegetation and wildlife exist only in the narrow zone of contact between the lithosphere, hydrosphere and atmosphere and that is known as biosphere.
- The life supporting system is called as the ecosystem. Here, living beings are inter-related and interdependent on each other for survival.
- There are innumerable uses of plants. They provide us with timber, give shelter to animals, produce oxygen, protects soils essentials for growing crops, help in storage of underground water, give us fruits, nuts, latex, turpentine oil, gum, medicinal plants and the paper.
- Animals big or small, all are integral and essential in maintaining balance in the ecosystem.
- A vital cleanser of the environment are the vultures and considered as scavengers because they have the ability to feed on dead livestock.
- Animals provide us milk, meat, hides and wool.
- Bees and birds have an important role to play as decomposers in the ecosystem.
→ Distribution of Natural Vegetation:
- Temperature and moisture are the factors for the growth of vegetation.
- The major vegetation types of the world are grouped as forests, grasslands, scrubs and tundra.
- In regions where heavy rainfall occurs, huge trees may thrive.
- In the regions of moderate rainfall, short stunted trees and grasses grow forming the grasslands of the world.
- In the regions of low rainfall, thorny shrubs and scrubs grow.
- Tundra vegetation of cold Polar Regions comprise of mosses and lichens.
- Population is growing in rapid way and to feed the growing numbers, large regions of forests have been cleared to grow crops. Forests are vanishing rapidly. An urgent need has come up to protect from destruction this valuable resource.
→ Conservation of Natural Vegetation and Wildlife:
- Many species have become endangered and some are on the verge of extinction.
- Some of the human and natural factors which gives momentum to the process of extinction of these resources are deforestation, soil erosion, constructional activities, forest fires, tsunami and landslides.
- Another major and important issue is poaching. The animals are poached for collection and illegal trade of hides, skins, nails, teeth, horns as well as feathers.
- The animals which are poached are tiger, lion, elephant, deer, blackbuck, crocodile, rhinoceros, snow leopard, ostrich and peacock. We need to create awareness to conserve these animals.
- To protect our natural vegetation and wildlife, national parks, wildlife sanctuaries, biosphere reserves are made.
- Awareness programmes such as social forestry and Vanainohatasava should be encouraged at the regional and community level.
- School children should also be encouraged to gain more knowledge about such awareness programs and try to conserve it.
- Laws has been passed in many countries against the trade as well as killing of birds and animals. In India, killing lions, tigers, deer, great Indian bustards and peacocks is illegal.
- Lists of several species of animals and birds in which trade is prohibited has been established by an international convention CITES.