Here is the notes for Class 8 NCERT Geography – Chapter 2: Land, Soil, Water, Natural Vegetation and Wildlife Resources

Land

• Land is among the most important natural resources.
• It covers only about thirty per cent of the total area of the earth’s surface and all parts of this small percentage are not habitable.
• The uneven distribution of population in different parts of the world is mainly due to varied characteristics of land and climate.
  
  • The rugged topography, steep slopes of the mountains, low-lying areas susceptible to water logging, desert areas, thick forested areas are normally sparsely populated or uninhabited.
  • Plains and river valleys offer suitable land for agriculture. Hence, these are the densely populated areas of the world.

Land Use

• Land is used for different purposes such as agriculture, forestry, mining, building houses, roads and setting up of industries. This is commonly termed as Land use.
• The use of land is determined by physical factors such as topography, soil, climate, minerals and availability of water.
• Human factors such as population and technology are also important determinants of land use pattern.

Land is classified on the basis of ownership

1. Private land
   • Private land is owned by individuals

2. Community land

   • community land is owned by the community for common uses like collection of fodder, fruits, nuts or medicinal herbs.
   • These community lands are also called common property resources.

Land degradation, landslides, soil erosion, desertification are the major threats to the environment because of the expansion of agriculture and construction activities.

Conservation of Land Resources

• Afforestation, land reclamation, regulated use of chemical pesticide and fertilisers and checks on overgrazing are some of the common methods used to conserve land resources.

Soil

• The thin layer of grainy substance covering the surface of the earth is called soil.
• Soil is made up of organic matter, minerals and weathered rocks found on the earth. This happens through the process of weathering.

Soil Profile

• Top soil with humus and vegetation
• Sub soil with sand, silt and clay
• Weathered rock material
• Parent rock

Factors of Soil Formation

• Parent Rock Determines colour, texture, chemical properties mineral, content, permeability
• Climate Temperature, Rainfall influence rate of weathering and humus formation
• Relief Altitude and slope, determine accumulation of soil
• Flora, Fauna and Micro-organism Affect the rate of humus formation
• Time Determines thickness of soil profile

Degradation of Soil and Conservation Measures

• Soil erosion and depletion are the major threats to soil as a resource.
• Both human and natural factors can lead to degradation of soils.
• Factors which lead to soil degradation are deforestation, overgrazing, overuse of chemical feritilisers or pesticides, rain wash, landslides and floods.

Soil Conservation

Some methods of soil conservation are

• Mulching: The bare ground between plants is covered with a layer of organic matter like straw. It helps to retain soil moisture.
• Contour barriers: Stones, grass, soil are used to build barriers along contours. Trenches are made in front of the barriers to collect water.
• Rock dam: Rocks are piled up to slow down the flow of water. This prevents gullies and further soil loss.
• Terrace farming: Broad flat steps or terraces are made on the steep slopes so that flat surfaces are available to grow crops. They reduce surface run off and soil erosion
• Intercropping: Different crops are grown in alternate rows and are sown at different times to protect the soil from rain wash.
• Contour ploughing: Ploughing parallel to the contours of a hill slope to form a natural barrier for water to flow down the slope
• Shelter belts: In the coastal and dry regions, rows of trees are planted to check the wind movement to protect soil cover

Water

• Water is a vital renewable natural resource.
• Three fourth’s of the earth’s surface is covered with water. It is therefore appropriately called the ‘water planet’.
• The ocean water is saline and not fit for human consumption.
• Fresh water accounts for only about 2.7 per cent. Nearly 70 per cent of this occurs as ice sheets and glaciers in Antarctica, Greenland and mountain regions.
• Only 1 per cent of freshwater is available and fit for human use. It is found as ground water, as surface water in rivers and lakes and as water vapour in the atmosphere.

Problems of Water Availability

• There is scarcity of water in many regions of the world. Most of Africa, West Asia, South Asia, parts of western USA, north-west Mexico, parts of South America and entire Australia are facing shortages in fresh water supply.
• Countries located in climatic zones most susceptible to droughts face great problems of water scarcity.

Conservation of Water Resources

• Forest and other vegetation cover slow the surface runoff and replenish underground water.
• Water harvesting is another method to save surface runoff. The canals used for irrigating field should be properly lined to minimise losses by water seepage.
• Sprinklers effectively irrigate the area by checking water losses through seepage and evaporation.
• In dry regions with high rates of evaporation, drip or trickle irrigation is very useful.
• The valuable water resource can therefore be conserved by adopting these means of irrigation.

Natural Vegetation

• Natural vegetation and wildlife exist only in the narrow zone of contact between the lithosphere, hydrosphere and atmosphere that we call biosphere.
• In the biosphere living beings are inter-related and interdependent on each other for survival. This life supporting system is known as the ecosystem.
• Vegetation and wildlife are valuable resources.
• Plants provide us with timber, give shelter to animals, produce oxygen we breathe, protects soils so essential for growing crops, act as shelter belts, help in storage of underground water, give us fruits, nuts, latex, turpentine oil, gum, medicinal plants and paper.

Wildlife

• Wildlife includes animals, birds, insects as well as the aquatic life forms.
• They provide us milk, meat, hides and wool. Insects like bees provide us honey, help in pollination of flowers.
• The birds feed on insects and act as decomposers.
• act as decomposers as well. Vulture due to its ability to feed on dead livestock is a scavenger and considered a vital cleanser of the environment.
• 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.
• So animals big or small, all are integral to maintaining balance in the ecosystem.

Distribution of Natural Vegetation

• The growth of vegetation depends primarily on temperature and moisture.
• The major vegetation types of the world are grouped as forests, grasslands, scrubs and tundra.
• Forests: The forests are thus associated with areas having abundant water supply. In areas of heavy rainfall, huge trees thrive.
• Grasslands: As the amount of moisture decreases the size of trees and their density reduces. Short stunted trees and grasses grow in the regions of moderate rainfall forming the grasslands of the world.
• Scrubs: Thorny shrubs and scrubs grow in dry areas of low rainfall. In such areas plants have deep roots and leaves with thorny and waxy surface reduce loss of moisture through transpiration.
• Tundra: Tundra vegetation of cold Polar Regions comprise of mosses and lichens.

Forests

• Forests are broadly classified as evergreen and deciduous depending on when they shed their leaves.
• Evergreen forests do not shed their leaves simultaneously in any season of the year.
• Deciduous forests shed their leaves in a particular season to conserve loss of moisture through transpiration.
• Both type of forests are further classified as tropical or temperate based on their location in different latitudes

Conservation of Natural Vegetation and Wildlife

• Changes of climate and human interferences can cause the loss of natural habitats for the plants and animals.
• Many species have become vulnerable or endangered and some are on the verge of extinction.
• Deforestation, soil erosion, constructional activities, forest fires, tsunami and landslides are some of the human and natural factors which accelerate the process of extinction of these resources.
• One of the major concerns is the poaching which result in a sharp decline in the number of particular species.
• Some of these animals are tiger, lion, elephant, deer, black buck, crocodile, rhinoceros, snow leopard, ostrich and peacock.
• National parks, wildlife sanctuaries, biosphere reserves are made to protect our natural vegetation and wildlife.
• Conservation of creeks, lakes, and wetlands is necessary to save the precious resource from depletion
• Awareness programmes like social forestry and Vanamohatasava should be encouraged at the regional and community level.
• Many countries have passed laws against the trade as well as killing of birds and animals.
• In India, killing lions, tigers, deers, great Indian bustards and peacocks is illegal

CITES

• 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.