Ecology: Meaning, Objectives and Classification of Ecology!
Ecology is a branch of science which deals with the study of interrelationship between biotic and abiotic components of nature as well as relationship among the individuals of the biotic components. Ecology has been defined in a number of ways by different scientists and ecologists.
Ernest Haeckel (1866), a German biologist, for the first time defined ecology as “the body of knowledge is concerning the economy of the nature the investigation of the total relation of animal to its inorganic and organic environment including above all its friendly and animal relations with those animals and plants with which it comes directly or indirectly into contact.” The term Ecology’ was derived from two Greek words, OIKOS (means house) and LOGUS (means study of) to denote the relationship between the organisms and their environment.
According to Woodbury (1954), “Ecology is a science which investigates organisms in relation to their environment’. E.P. Odum (1969) defined ecology as “the study of structure and function of nature”. R Margalef (1968) treated ecology as “study of ecosystems”.
In 1985, Charles Krebs proposed the most accepted definition of ecology which may be defined as follows: “Ecology is the scientific study of the interactions that determine the distribution and abundance of organisms”.
Thus, modern ecologists have broaden the definition of ecology considering all the fundamental aspects in the subject. Anyway, ecology is primarily a biological science in as much as it deals with the inter-relationships of organisms with their environment.
Ecology plays a significant role in our day to day life. It is concerned with agriculture, horticulture, conservation of soil, wildlife, forest, water resources, etc. Its domain is so vast that it cannot be confined with limited discussion. However the study of ecological principles provides background knowledge for understanding the problems of forests, soil, surface water etc.
Objectives of Ecology:
The importance of ecology lies in the comprehensive understanding of its objectives.
The important concepts discussed below throw light on various aspects of ecology:
(i) The local and geographical distribution and abundance of organisms (habitat niche, community, bio-geography).
(ii) Temporal changes in the occurrence, abundance and activities of organisms (seasonal, annual, successional, geological).
(iii) The inter-relationship between organism in population and communities (population ecology).
(iv) The structural adaptations and functional adjustment of organisms to their physical environment.
(v) The behaviour of organism under natural conditions (ethology).
(vi) The evolutionary development of all these inter-relations (evolutionary ecology).
(vii) The biological productivity of nature and its relations with mankind.
(viii) The development of mathematical models to relate interaction of parameters and predict effects (systems analysis).
(ix) The conservation and management of natural resources and pollution (applied ecology).
Classification of Ecology:
Broadly speaking, the important sub-divisions of ecology are animal ecology and plant ecology. It is also classified as autecology and synecology. Autecology deals with the ecological study of one species of organism. Synecology deals with the ecological studies of communities or entire eco-systems.
However, we can classify ecology into following branches:
(i) Habitat Ecology:
It deals with ecological study of different habitats on planet earth and their effects on the organisms living there.
(ii) Community Ecology:
It deals with the study of the local distribution of animals in various habitats. Also, it is related with the recognition and composition of community units, and succession.
(iii) Population Ecology:
This is also known as demonology. It deals with the study of the pattern of growth, structure and regulation of population organism. The population ecology also deals with interactions between populations of different species in a community.
(iv) Evolutionary Ecology:
It is concerned with the problems of niche segregation, and speciation.
(v) Taxonomic Ecology:
It is related with the ecology of different taxonomic groups of living organisms.
(vi) Human Ecology:
It is mainly related to population ecology. It studies the inter-relationship between man and man along-with the environment. Effects of human beings on the biosphere and the implications of these effects for mankind is the subject matter of human ecology.
(vii) Applied Ecology:
It is an important sub-division of ecology. It deals with the practical aspect of ecology. Mainly the application of ecological concept to human needs is the field of this study. We find wild-life management, forestry, conservation, insect control, animal husbandry, aqua-culture, agriculture, horticulture, land use, population ecology etc. as the application of ecology in practical life.
(viii) Eco-system Dynamics:
It deals with the ecological study of the process of soil formation, energy flow, productivity etc.
(ix) Production Ecology:
It examines the gross and net production of different eco-systems like fresh water, sea water, agriculture, horticulture etc. Production ecology attempts for the effective management of the eco-systems so as to maximise the production.
(x) Ecological Energetics:
It deals with energy conservation and its flow in the organisms within the eco-system.
(xi) Physiological Ecology (Eco-physiology):
The factors of environment have direct relation with the functional aspects of the organism. The eco-physiology deals with the survival of the population as a result of functional adjustment of organisms with different ecological conditions.
(xii) Chemical Ecology:
It is related with the adaptation of animals of preferences of particular organisms like insects to particular chemical substances.
(xiii) Ecological Genetics:
An ecologist recognised the kind of genetic plasticity in the case of every organism. In any environment only those organisms that are supported by the environment can survive. Thus, genecology deals with the study of variations of species based on their genetic potentialities.
(xiv) Palaeo Ecology:
It is the study of environmental conditions and life of the past ages.
(xv) Geographic Ecology (Eco-geography):
It focuses light on the study of geographical distribution of animals and plants.
(xvi) Space Ecology:
It is concerned with the development of partially or wholly regenerating eco-systems for supporting the life of man during long space flights.
It deals with the study of soil, especially their acidity, human contents, mineral contents, soil types, etc. and their influence on their organism.
(xviii) Radiation Ecology:
It studies the gross effect of radiation and radio-active substances over the environment and living organisms.
It studies the animal behaviour under natural conditions.
It is the study of ecology and ethology of mankind.
(xxi) System Ecology:
It deals with the analysis and understanding of the function and structure of eco-system through the use of applied mathematics, advanced statistical techniques, mathematical models etc.