2. 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.
3. 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.
4. • 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”.
5. 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.
6. • 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.
7. 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.
9. 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.
11. CLASSIFICATION OF ECOLOGY
on 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.
15. 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.
18. 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.
19. 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.
20. • 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.
21. 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
