Dominance, Richness and Evenness

ENVIRONMENTAL FACTORS OF ECOLOGY

Environmental factors of ecology divided to:

1. Biotic factors

Biotic factors are all organism that share an environment. Biotic component are all the living beings in an environment, from protist to mammalians. Individuals should have spesific behavioral an physiological characteristic that permit their survival and reproduction in a defined environment. The condition of sharing environment generates a competence among the species, competence that is given for food, space, etc.

2. Abiotic Factors

Abiotic factors are inert factors of the ecosystem, there are:

v  Climate factors

Atmospheric condition of a region over a long period of time. For example:

·       Light

Light plays an important role in the species composition and development of vegetation. Light is abundatly received on the surface of the earth, and on an average approximately only 2-3 per cent of this solar energy is used in primary productivity.

    Light intensity shows special variations due to the factors like atmospheric water layer, particles di dispersal in the air, etc. Further, the vegetation of an area may also affect the light intensity. In deep shade under trees, or under water, light becoming limiting below photo-synthesis is not sufficient for effective growth.

·       Temperature

Temperature is a measurement of the degree of heat. Like light, heat is a form of energy. The radiant energy received from the sum is converted into heat energy. Heat is measured in calo­ries. The temperature at which physiological processes are at their maximum efficiency is called optimum temperature.

The mini­mum, optimum and maximum temperatures are called cardinal temperatures. The cardinal temperature varies from species to species, and in the same individual from part to part. The distributions of plants, animals are also influenced by tem­perature.

·       Water

Water is an indispensable part of land and soil productivity. The misuse of water leads to soil degradation and erosion. Proper management of water is highly necessary for better production. Water is also indispensable for human beings.

Thus, it goes without saying that water is the most important substance necessary for life. All the physiological processes take place in the medium of water. Protoplasm, the very basis of life, is made up mostly of water. Plants and animals show considerable variation in their re­quirements of water.

·       Rainfall

The main source of soil water is precipitation. The rainfall pro­vides water to plants and animals. Rainfall occurs due to inter­change of water between earth’s surface and the atmosphere. This is known as the hydrologic cycle. In this cycle two important things are precipitation and evapo-transpiration.

·       Wind

Air in motion is called wind. It is a vital environmental factor. It affects plants, and other organisms. It modifies the water rela­tion and light conditions of a particular region. Wind brings about a number of physical, anatomical and physiological changes of plants. Such changes are breakage and uprooting of plants, de­formation, erosion and deposition,, salt spray etc.

·       Humidity

Atmospheric moisture in the form of invisible vapour is known as humidity. Humidity is greatly influenced by intensity of solar radiation, temperature, altitude, wind, water status of soil etc. Low temperature causes higher relative humidity by decreasing the capacity of air for moisture. Processes as transpiration, ab­sorption of water etc. are influenced by atmospheric humidity. Humidity, thus, plays an important part in the life of plants and animals.

·       Atmospheric Gases

Some principal gases like nitrogen, oxygen, carbon-dioxide, helium, hydrogen, methane, ozone etc. are found in atmosphere. In addition to these gases, there are water vapours. Industrial gases, dust, smoke particles, micro-organisms etc. are present in the atmosphere. These gases have important influence on the environment.

v Edaphic Factors

Edaphic factors deals with different aspects of soil, such as the structure and composition of soil, its physical and chemical fea­tures. A galaxy of complex factor constitutes the soil.

v Topograpic Factors

The factors concerned with physical geography of the earth are known as topographic factors. These factors influence vegetation which causes variation in climate of a geographic region, ultimately give rise to a characteristic microclimate.

Addition

v Limiting Factors

A limiting factor is that substance of quality in the environment, the supply of which is least abundant or over abundant in rela­tion to the need of the living organism concerned.