PRINCIPLES AND SCOPE OF ECOLOGY

Ecology is the study of organisms and their relation with their surroundings. In fact, ecology is the scientific study of how organisms interact with each other and with their Environment. Ecologists have determined the principles that govern the distribution and abundance of organisms in ecosystems, and the tenets of ecology have become as crucial to human survival as natural history once was to our ancestors. Though ecology as a science is fairly young, yet the perspectives of the environment emanating from it are very useful in understanding the latter. It is also quite useful in putting together a realistic philosophy regarding the environment.

The relationship of each of these components is based on some principles some of which are summarized below:

1. Environment in a habitat comprises the non-living and living components, the activities of which are influenced by the combined effect of various forces acting on them.

2. Anything and everything that influences the life process of an organism, directly or indirectly, constitutes its environment.

3. An organism cannot exist in vacuum.

4. The requirement of environmental forces for different living organisms differ from individual to individual and vary with age and stage.

5. There is always a range of environmental factors above or below which the performance or function of a living organism declines. For example, man performs best under temperature conditions ranging from 25o C to 32o C. At very high or very low temperatures even survival becomes difficult. Similarly, for an insect, say mosquito of a particular type, this range will vary. However, for any individual there has to be a minimum and maximum range in which it performs well. Further, for different environmental factors the tolerance limit in a particular living system could be different.

6. The organisms with wide tolerance limits for many environmental factors are widely distributed.

7. The organisms react with external stimuli caused by environmental changes. These responses may range from quick growth to death or migration or adaptation and so on.

8. Each has a capacity to support certain number of living individuals. The capacity is known as carrying capacity of the habitat. For example: carrying capacity of a city or carrying capacity of cattle in grasslands.

9. The environment of every habitat is in a state of constant flux or change. This change is directional and in successive phases. For example, if we do not interfere with nature on a piece of land, we will after a certain time period get a forest, where trees, shrubs, herbs, herbivores, carnivores, parasites and saprophytes shall live together in harmony with nature. Thus, change is also permanent.

10. Sun is the only primary source of energy on which life sustains. Plants prepare food for animals by harvesting solar energy.

11. The life on earth exists in a thin mantic or layer around the earth’s surface. This sphere is called biosphere which comprises many life supporting habitats often called ecosystems.

12. In every ecosystem (ecological system which is dynamic, that is where there is a flow of energy from plants to animals and micro organisms etc.) there are producers (those who produce energy i.e. plants) consumers (those who consume producers, herbivore or in turn the primary consumers-carnivorous animals) and decomposers (those who decompose the dead matter) who interact among themselves and influence and get influenced from the non living component of the environment.