ABIOTIC FACTORS

INTRODUCTION

Abiotic and biotic factors or components are present in environment of an organism. The abiotic factors includes the atmosphere(air), hydrosphere (water), and lithosphere( land including soil).The abiotic factors are characterized by physical and chemical factors such as light, temperature, rainfall, pressure, pH, the content of oxygen and other gases. The biotic factors include all living organisms which interact with each other and their physical or abiotic environment (including air, water and land) .

In physical terms, the biosphere is a relatively thin and incomplete envelope covering most of the world. It represents a mosaic of different biotic communities from simple to complex, aquatic to terrestrial, and tropical to polar. It does not exist in extremities of the polar regions, the highest mountains, the deepest ocean troughs, the most extreme deserts, or the most highly polluted areas of land and water. Its total thickness, including all portions of the earth where living organisms can exist, is less than 26 kms.

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 ABIOTIC ENVIRONMENTAL FACTORS AND ITS TYPES

Abiotic factors: The non-living factors that have influence on ecosystem. Examples: air, water, light and land etc.

Abiotic environmental factors are customarily classifies as follows:

1. Climatic Factors

1. Light
2. Temperature
3. Water
4. Atmosphere
5. Fire

2. Topographic or physiographic factors

1. Altitude
2. Direction of mountain chains and valleys
3. Steepness and exposure of slopes

3. Edaphic factors

(soil formation, physical and chemical properties of soil, nutrients).

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CLIMATIC FACTORS

1. LIGHT

The light energy from the sun is the basic requirement for the existence of life on the earth. This form of energy is important for photosynthetic production of food by plants .

Although we think light in the form of visible light, the sun emits other radiations of different wavelengths- cosmic rays, gamma rays, X-rays, ultraviolet rays, infrared rays, etc.

2. TEMPERATURE

Temperature is one of the essential and changeable environmental factor. It is present everywhere in the biosphere and influences all forms of life by exerting its action through increasing or decreasing some of the vital activities of organism, such as behavior, metabolism, reproduction, etc.

Every life activity takes place on a specific temperature or at a specific range of temperature.

3. PRECIPITATION (RAIN FALL)

The moisture falling on an area in liquid, vapors or frozen form is termed as precipitation. Precipitation includes rain, snow, hail and dew.

Due to water cycle, there occurs an interchange of water between the earth’s surface and the atmosphere.

4. HUMIDITY OR AIR

Atmospheric moisture in the form of invisible vapor is known as humidity. Humidity is greatly affected by intensity of solar radiation, temperature, altitude, wind exposure, cover and water status of soil.

Humidity plays an important role in the life of plants and animals. It affects the life processes such as transpiration, absorption of water, etc.

5. FIRE

Fire is of a common occurrence in natural vegetation all over the world; it is more common in drier habitats than the wet.

Lightening is the most common natural cause of fire initiation. Other causes of fire are abrasive effects of falling rocks or of dried plant material such as bamboos, or spontaneous combination of very dry and hot material or by volcanic activities.

6. WIND

The strong moving current of air is called wind. Wind affects various plant life on flat plains, along sea coasts and at high altitudes in mountains. Wind also modifies the water relations and light conditions of a particular area. Wind results in various physical, anatomical and physiological effects on plants: 1. Physical effects, 2. Anatomical effects.

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PHYSIOGRAPHIC FACTORS

Physiographic factors are those which are introduced by the structure, conformity and behaviour of the earth’s surface, by topographic or orographic features.

1. LATITUDES AND ALTITUDES

Latitude represents distance from the equator. Temperature values are maximum at the equator, decreasing gradually towards poles.

Height above the sea level forms the altitude. At high altitudes, the velocity of wind remains high, temperature and air pressure decrease, humidity as well as intensity of light increases.

2. HEIGHT OF MOUNTAIN CHAINS’

Effects of different heights (altitudes) can be better seen on mountains. With an increase in altitude above sea level, there are changes in values of temperature, pressure, wind velocity, humidity, intensity of solar radiation, etc.

3. DIRECTION OF MOUNTAINS AND VALLEYS

The direction of mountain chains or ranges and high mountains act as wind barriers and affect the climate. Mountains also steer or deflect winds into different directions and capture moisture from wind on certain sides to cause precipitation.

4. STEEPNESS OF SLOPE

Slope is the characteristic feature of mountains. The steepness of a slope has a distinct effect on the climate of the area, i.e., incidence of solar radiation, rainfall, wind velocity and the temperature of the region.

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EDAPHIC FACTORS

Soil formation

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CONCLUSION

Abiotic factors are the non-living factors which have influence on ecosystem. Such as water, air, humidity, temperature, rainfall etc. All these abiotic factors are very important for the life of every organism, including animals and plants.

Abiotic factors includes climatic factors, physiographic factors and edaphic factors.

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