ECOLOGY

BY; SYED AASIM HAQ M.Sc. ZOOLOGY DEPARTMENT OF ZOOLOGY ALIGARH MUSLIM UNIVERSITY

INTRODUCTION• ECOLOGY

• Derived from Greek word ; (Oikos-House & Logos-Study of)

• It is the study of inter-relationships between organisms and their environment.

• It is the science that attempts to answer questions about how the nature works.

HISTORY• Hippocrates(4th century BC); In an

paper entitled “Air, Water and Places” stressed on the need of ecological background for medical students.

• Aristotle(4th century BC); Studied the habits of animals and environmental conditions of certain areas.

• Theophrastus(4th century BC); First ecologist to describe the inter-relationship between plants and their physical environment.

• Thomas R. Malthus; Wrote an essay on “Human Population” and proposed that keeps balance between organism and nature.

• Ernst Haeckel(1866); coined the term Ecology in his book “Generelle Morphologie der Organismen”.

DEFINITIONS OF ECOLOGY

• Ernst Haeckel; It is the relation of animals to its organic(living) and inorganic(non-living) environment.

• Charles Elton; It is the scientific natural history concerned with sociology and economics of animals.

• Allee; It is the science of inter-relationship between living organisms and their environment.

• Odum; Ecology is the study of structure and functions of nature.

• Tailor; Ecology is the study of all relations of organisms to all of their environment.

ECOLOGICAL LEVELS OF

ORGANISATION• Organisation is the arrangement of smaller

components into larger ones and so on a hierarchy or a pyramid in which components of each level coordinate with one another towards a common goal.

• Organisation is regulated by ; aggregation, interaction, equilibrium and variations.

• Basic Level of ecological organisation is Individual and largest is Biosphere.

ECOLOGICAL LEVELS OF ORGANISATION

CLASSIFICATION OF ECOLOGY

on the basis of ecological group

• Autoecology(population ecology); It is the study of reciprocal relationship between the individuals of population or populations of same species.

• Synecology(community ecology); It is the study of reciprocal relationship between the members of different populations of the biotic community.

Autoecology(population ecology)

Synecology(community ecology)

CLASSIFICATION OF ECOLOGYon the basis of habitat or environment

• Marine Ecology(oceanography); Study of inter-relationship between the biotic and abiotic components of oceans,seas,bays & estuaries.

• Fresh-water Ecology(limnology); Study of inter-relationship between biotic and abiotic components of rivers, streams, lakes, reservoirs, etc.

• Terrestrial Ecology; Study of inter-relationship between biotic and abiotic components of land. It includes deserts ecology, forest ecology, grassland ecology, cropland ecology, etc.

Terrestrial Ecology

Marine Ecology

Fresh-water Ecology

OTHER CATEGORIES OF ECOLOGY• Human Ecology • Space Ecology • Applied ecology• Production Ecology• Paleoecology• Biogeography• Taxonomic Ecology• Cytoecology• Pedoecology

• Physiological Ecology• Conservational Ecology• Radiation Ecology

ECOSYSTEM• Ecosystem ; Any unit which includes all the

organisms (community) in an given area interacts with physical environment by means of food chain and chemical cycles resulting in energy-flow, biotic diversity & material cycling.

• It can be permanent & natural or temporary & artificial.

• Odum(1963); Ecosystem is the basic functional unit of Ecology.

• A.G.Tansely(1935); coined the term ecosystem.

TYPES OF ECOSYSTEM

Terrestrial

Natural Artificial

Marine

Fresh water

Grassland

Savannah

Taiga

Tundra

Desert

Forest

Man made

Aquatic

STRUCTURE OF ECOSYSTEM

FUNCTIONAL ASPECT OF ECOSYSTEM

Main functional aspects of an ecosystem are ;

• Food chains and Food webs.• Energy flow.• Biogeochemical cycles.• Cybernetics or control.• Diversity pattern.

SIGNIFICANCE OF ECOLOGY

• In conservation of natural resources.

• In restoration of our natural environment to ensure human survival.

• Protection of animal and plant species from extinction.

• Conservation of bio-diversity.

• It helps in reduction of pollution.

• It laids down emphasis on the use of bio-fertilizers over the chemical ones or man made which is threatening our natural climate ,flora and fauna.

REFERENCES• Comparative Physiology, Developmental Biology

And Ecology(Ashok Sabharwal); Modern Publication.

• Odum• Fundamentals of Life Sciences ; Pathfinder

Publication.• Wikipedia• www.ck12.org• www.bio.miami.edu/dana/160/160S13_21.html• www.ecologyedu.com• www.yourarticlelibrary.com