Biological world lives within and depends on the abiotic environment. Some of the abiotic environmental factors like climate, soil and topography of a region are responsible for a particular type of vegetation of that region.
This is the region why vegetation of Shimla and Kashmir differs from Jaipur and Jaisalmer. The ability of organism to utilize, tolerate or combat the various abiotic factors is different and it may limit their distribution, behaviour and relationship with other organism.
Our current atmosphere is a mixture of many different gases and suspended particles. These gases in the lower atmosphere undergoes continual mixing and therefore the composition of our atmosphere is almost the same everywhere upto an altitude of 80 km. Higher than 80 km these gases become stratified i.e. the heavier gases comprises the lower layer and higher gases comprises the upper layers.
Atmosphere nitrogen cannot be utilized by organism directly (except few bacteria and blue green algae). It is first converted into nitrate and then utilized by plants and other organisms.
This process is nature is called nitrification. Oxygen important for respiration and is in the energy releasing process for all the organisms on the earth. Carbon dioxide gas is the most important gas for all green plants.
In photosynthesis green plants utilize C02 and water as raw material and convert solar energy to chemical energy on which the entire living system depends. Ozone (03) is formed in the upper atmosphere by action of solar energy on oxygen, shields all living beings from the harmful effects of ultraviolet rays from the Sun. The atmosphere contains minute liquid or solid particles.
These are known as aerosols. Most of these found near the earth’s surface and originate as a result of soil erosion due to wind, forest fires, and salt crystals from oceanic sprays and in volcanic eruptions. Another source of aerosols is industrial and agricultural activity.
Although the aerosol content of atmosphere is very small, yet these suspended particles are important. For example some particles act as nuclei for formation of clouds and precipitation, while other influence air temperature by interacting with sunlight.
The first and foremost requirement of life is energy and sunlight. Solar radiation is the chief source of energy on the planet. Sunlight evaporates water that later fails as rain. It also heats up the earth unevenly causing winds to blow.
Photosynthesis in green plants stored energy also transpiration movement, flowering (Photoperiodism) and germination in plants done by light. Most of animals are sensitive to light. Photoreceptors in animals and bats are active during night.
All living organism are influenced by temperature. The range of temperature in which an organism can survive is known as ‘tolerance limit’.
Minimum temperature is that on which the activity starts, maximum beyond which activity is not possible and optimum at which it is at its highest pace. Relatively few organisms survive body temperature above 45°C.
The strong moving current of air or wind determines weather condition and becomes an important environmental factor for some organisms.
Plants are highly influenced by wind. The evapo-transpiration is directly affected by strong or slow wind. On higher altitude wind velocity is very high affect shape and canopy of tree. Wind also helps in dispersal of seeds and fruits.
Amount of water vapour or moisture in the atmosphere is known as humidity. When atmosphere holds the maximum quantity of moisture at a fixed temperature and pressure then it is known as absolute humidity.
Relative humidity of a particular area is influenced by temperature, air pressure (altitude) wind velocity, vegetation and soil moisture. Relative humidity declines if atmosphere is warmer and increase in cool conditions.
Water is an essential requirement of life. Most civilization started near rivers because water is the basis of life, needed for domestic, irrigational and industrial purposes. There are organism that lives both in water and land (amphibians), inside the water (aquatic-hydrophytes).
Soil is the chief reservoir of mineral elements (nutrients) required by the plants and other organism. The quantity of available nutrients the water holding capacity and aeration of the soil play major roles in determining soil fertility. This effect the plant productivity and number of organism that soil can support.
When light falls on an area having green vegetation, most of light is intercepted by green plants and little fraction reaches up to ground surface. But when sunlight falls on places devoid of vegetal cover, the soil surface warms up quickly.
That’s why the microclimate of urban area is different than villages. Similar relationship also occurs between rainfall and temperature.