The World Of Living


Surrounding effect of living


Climate means the usual condition of the temperature, humidity, atmospheric pressure, wind, rainfall, and other meteorological elements in an area of the earth's surface for a long time. Climate is different from weather. Weather is the condition of these elements right now, for shorter periods of time that are up to two weeks.

The latitude, ground, and height can change the climate of a location. It is also important to note if oceans or other large bodies of water are nearby. Climates are most commonly classified by temperature and precipitation. Climates can change after a long time. Recently, the world may be becoming warmer, as is discussed in global warming.

The climate of a place is given names such as temperate, arid, cold, dry, tundra, tropical, equatorial, mediterranean, savanna, etc.

  • Subarctic regions have a subarctic climate (also called boreal climate), characterized by long, usually very cold winters, and short summers.
  • Temperate climates have four seasons. Some of the countries which have temperate climate are: Turkey and most of the European countries.
  • Arid climates are hot climates, like deserts. They just have one or two seasons such as: Saudi Arabia and most of the African countries.
  • Tropical climates have warm temperature and only two seasons; wet and dry. An example of a place with a tropical climate is the Amazon Rainforest in Brazil.
  • The Mediterranean climate is usually hot and dry in summer, and is cool and wet in winter. An example of a country with a mediterranean climate is Spain.
  • The Savannas' climate is often wet and dry.


Soil is the thin top layer on the earth's crust comprising rock particles mixed with organic matter.

  • Pedology is the study of soils in their natural environment. Pedogenesis is the natural process of soil formation that includes a variety of processes such as weathering, leaching, calcification etc.
  • The soil formation is mainly related to the parent rock material, surface relief, climate and natural vegetation.
  • The soil is formed by the breaking down of rocks by the action of wind, water and climate. 

Soil Types - Sandy-Clayey-Loamy


The soil is classified on the basis of the proportion of particles of various sizes.

  • If soil contains greater proportion of big particles it is called sandy soil.
  • If the proportion of fine particles is relatively higher, then it is called clayey soil.
  • If the amount of large and fine particles is about the same, then the soil is called loamy soil.
  1. Water can drain quickly through the spaces between the sand particles. So, sandy soils tend to be light, well aerated and dry.
  2. Clay particles, being much smaller, pack tightly together, leaving little space for air. Unlike sandy soil, water can be held in the tiny gaps between the particles of clay. So clay soils have little air. But they are heavy as they hold more water than the sandy soils.
  3. The best topsoil for growing plants is loamy soil is a mixture of sand, clay and another type of soil particle known as silt. Silt occurs as a deposit in river beds. The size of the silt particles is between those of sand and clay. The loamy soil also has humus in it. It has the right water holding capacity for the growth of plants.
  • A vertical section through different layers of the soil is called the soil profile.
  • Each layer differs in feel (texture), colour, depth and chemical composition. 
  • A soil horizon is a layer generally parallel to the soil surface, whose physical characteristics differ from the layers above and beneath.
  • Horizons are defined in most cases by obvious physical features, chiefly colour and texture.
  • The uppermost horizon is generally dark in colour as it is rich in humus and minerals. The humus makes the soil fertile and provides nutrients to growing plants.
  • This layer is generally soft, porous and can retain more water. It is called the topsoil or the A-horizon.
  • The next layer has a lesser amount of humus but more of minerals. This layer is generally harder and more compact and is called the B-horizon or the middle layer.
  • The third layer is the C-horizon, which is made up of small lumps of rocks with cracks.

O Horizon

  • Layers dominated by organic material.
  • Some O layers consist of undecomposed or partially decomposed litter (such as leaves, needles, twigs, moss, and lichens).
  • They may be on top of either mineral or organic soils.

A Horizon or Surface soil

  • It is the part of top soil.
  • In this layer, organic matter is mixed with mineral matter.
  • It is the layer of mineral soil with the most organic matter accumulation and soil life.
  • This layer is depleted of (eluviated of) iron, clay, aluminum, organic compounds, and other soluble constituents.
  • When depletion is pronounced, a lighter colored "E" subsurface soil horizon is apparent at the base of the "A" horizon.

E horizon

  • "E" stands for eluviated layer.
  • It is the horizon that has been significantly leached of clay, iron, and aluminum oxides, which leaves a concentration of resistant minerals, such as quartz, in the sand and silt sizes.
  • These are present only in older, well-developed soils, and generally occur between the A and B horizons.

B Horizon or Subsoil

  • It is subsurface layer reflecting chemical or physical alteration of parent material.
  • This layer accumulates all the leached minerals from A and E horizon.
  • Thus iron, clay, aluminum and organic compounds accumulate in this horizon [illuviation (opposite of eluviation)].

C Horizon or Parent rock

  • Weathered parent material accumulates in this layer, i.e. the parent material in sedimentary deposits.
  • It is a layer of large unbroken rocks.
  • This layer may accumulate the more soluble compounds (inorganic material).

R Horizon or Bedrock

  • This layer denotes the layer of partially weathered bedrock at the base of the soil profile.
  • Unlike the above layers, R horizons largely comprise continuous masses of hard rock.
  • Soils formed in situ will exhibit strong similarities to this bedrock layer.
  • These areas of bedrock are under 50 feet of the other profiles.


Different types of soils are found in different parts of India. In some parts there is clayey soil, in some parts there is loamy soil while in some other parts there is sandy soil. Soil is affected by wind, rainfall, temperature, light and humidity. These are some important climatic factors which affect the soil profile and bring changes in the soil structure. The climatic factors, as well as the components of soil, determine the various types of vegetation and crops that might grow in any region.

Clayey and loamy soils are both suitable for growing cereals like wheat, and gram. Such soils are good at retaining water. For paddy, soils rich in clay and organic matter and having a good capacity to retain water are ideal. For lentils (masoor) and other pulses, loamy soils, which drain water easily, are required. For cotton, sandy loam or loam, which drain water easily and can hold plenty of air, are more suitable.

Crops such as wheat are grown in the fine clayey soils, because they are rich in humus and are very fertile.

Climate and adaptation

Climate has a profound effect on all living organisms.

Animals are adapted to survive in the conditions in which they live. Animals living in very cold and hot climate must possess special features to protect themselves against the extreme cold or As the name suggests, the polar regions are situated near the poles, i.e., north pole and south pole.

(i) The polar regions

The polar regions present an extreme climate. These regions are covered with snow and it is very cold for most parts of the year. For six months the sun does not set at the poles while for the other six months the sun does not rise. In winters, the temperature can be as low as -37°C. Animals living there have adapted to these severe conditions. Examples: polar bears and penguins.

Polar bears have white fur so that they are not easily visible in the snowy white background. It protects them from their predators. It also helps them in catching their prey. To protect them from extreme cold, they have two thick layers of fur. They also have a layer of fat under their skin. In fact, they are so well-insulated that they have to move slowly and rest often to avoid getting overheated. another well-known animal living in the polar regions is the penguin. It is also white and merges well with the white background. It also has a thick skin and a lot of fat to protect it from cold like polar bears. Penguins are also good swimmers. Their bodies are streamlined and their feet have webs, making them good swimmers.

Other animals living in the polar regions are many types of fishes, musk oxen, reindeers, foxes, seals, whales and birds. It is to be noted that while fish can remain under cold water for long, birds must remain warm to survive. They migrate to warmer regions when winter sets in.

(ii) The tropical rainforests

The tropical region has generally a hot climate because of its location around the equator. Even in the coldest months, the temperature is generally higher than about 15°C. During hot summers, the temperature may cross 40°C. Days and nights are almost equal in length throughout the year. These regions get plenty of rainfall. An important feature of this region is the tropical rainforests. Because of continuous warmth and rain, this region supports wide variety of plants and animals. The major types of animals living in the rainforests are monkeys, apes, gorillas, lions, tigers, elephants, leopards, lizards, snakes, birds and insects.

Since the numbers are large, there is intense competition for food and shelter. Many animals are adapted to living on the trees. Red-eyed frog has developed sticky pads on its feet to help it climb trees on which it lives. To help them live on the trees, monkeys have long tails for grasping branches. Their hands and feet are such that they can easily hold on to the branches. Many tropical animals have sensitive hearing, sharp eyesight, thick skin and a skin colour which helps them to camouflage by blending with the surroundings. This is to protect them from predators. For example, lions and tigers have thick skins and sensitive hearing.