Introduction to Ecology/ Population/ Ecosystem/ Community/ Biosphere/ Autecology/ Synecology
Introduction of Ecology
Ecology is the study of how organisms interact with one another and with their physical environment. The core goal of ecology is to understand the distribution and abundance of living things in the physical environment. An ecologist studies the relationship between living things and their habitats. Ecologists must study and observe all forms of life and their ecosystems throughout our world.
The main objective of ecology is to understand the nature of environmental influences on individual organisms, their populations, and communities, on ecosystems and ultimately at the level of the biosphere.
• Concept
of Ecology
Term Ecology is
derived from “Oekologie”.
The word ‘ecology’
(oekologie), first proposed by Earnst Haeckel (1869), a German Biologist, is
derived from Greek words, oikos meaning the dwelling place or home and logos
meaning the discourse or study; thus, the word ecology literally means the
study of living organisms, both plants and animals in their natural habitats or
homes.
Definition – Ecology
is “a study of animals and plants in their relation to each other and to their
environment”.
• It can also be defined as the study of life in relation to environment; the environment being the aggregate of all external conditions and influences which affect the life and development of organisms at a given spot.
• Recently,
Eudgene
Odum (1963) has defined ecology as the study of the structure and the
function of nature.
• According
to charles
J. Krebs (1972), ecology is the scientific study of interactions that
determine the distribution and abundance of organisms.
• Smith
R.L. (1972) in his book elements of ecology and field biology has defined ecology as
multidisciplinary science which deals with organisms and their environment,
both biotic and abiotic.
• Ecology
is studied with particular reference to plants or to animals, hence the Named
as Plant ecology and Animal ecology. Since plants and animals are intimately
inter-related. Organisms,(Plants or animals) form interacting systems or
communities, these communities are coupled to their environments by transfer of
matter and energy and so the communities and environment are interrelated.
A functional system formed by communities and their environment is called
ecosystem. Thus ecology is a science of ecosystems or totality of reciprocal
interactions between living organisms and their physical surroundings. (Clark,
M.E. 1973).
• Ecology,
like biology, has been subdivided into plant ecology and animal ecology.
• Plant ecology
deals with the relationship between plants and their environments .
• Animal
ecology is concerned with the study of relationship between animals and
their environments.
• Ethology
is the term now generally used by biologists to denote the scientific study of
animal behaviour with special reference to the behaviour of animal in its
normal environment.
• The fundamental ecology deals with five higher levels of organization-
• 1.
Individual organism,
• 2.
Population
• 3 . Community
• 4. Ecosystem
• 5.
Biosphere
• 1.
Individual Organism
• An organism is
the simplest level of organization in ecology. an organism is
A living individual animal, bacteria, or thing.
They make the basic unit of study in ecology. At this level, the form,
physiology, behaviour, distribution and adaptations of an individual species in relation to the
environmental conditions are studied by the ecologist.
• No
two organisms are alike. That means there's a certain amount of variability in
a group of organisms, and some might be better suited to their environment than
others. The better-suited organism live longer, get stronger, and make
offspring that are similar to them. Meanwhile, the not-so-fit organism die off.
• Every
ecological level bigger than Organism includes more than one interacting
organism.
2. Population
in ecology, a population is a group of individuals of the same species,
inhabiting the same area at a specific time.
• For example, all individuals of the common grass, Cynodon, in a given area i.e. grassland, constitute its population. Similarly, the individuals of Deer or elephants or tigers in an area constitute their population.
The interaction between populations is generally studied by the ecologist. These
interactions may be a predator and its prey, or a parasite with its host.
Competition, mutualism, commensalism, parasitism, and predation are various
types of interactions.
• Ecologist
have recognise two types of populations.
• 1.
Monospecific population- population of individuals of only One species.
• 2.Polyspecific
population- population of individuals of several
species.
• Population
of any species grows in size with response to environmental conditions.
• Environmental
factors like air, water and food play important role to control the growth of
any population.
• If
environmental conditions are favorable for growth, the population grows faster
due to Course of time population will become excessive environmental resources
like food and space becomes limited, results competition among organisms for
survival, finally growth rate drops and
the population is controlled.
3. Community
• Concept
of community was coined by Forbes in 1844. Community is an assemblage or
group of number of organisms, of different types of species living together in
the same area or natural habitat.
Communities interact with each other and forms mutual and beneficial
relationships.
• For
example in forest area there are number
of animal and plant species that live together. There is a chain of producers,
herbivores, carnivores and microorganisms that forms a biotic community. There
is interdependence among these
components of forest community. Consequently, chain of interdependence and interactions results to
build ecosystem structure.
• Each
community has its own composition structure origin and development some of the
community characteristics are diversity e dominance , richness and abundance.
4. Ecosystem
• The
concept of ecosystem was propose by A.G.Tansley in 1935.
• Ecosystem
is defined as “The inter-relationships between living and non-living factors
within the environment”.
• The
relationship between living things and their environment facilitates the flow
of matter and energy within the ecosystem.
• An
ecosystem has two basic components:
(i) Abiotic componants:These are non-living things found in the
environment. Abiotic componants or factors includes light. Temperature,
climate, soil, Air, water, inorganic and organic materials present in the
surrounding.
(ii) Biotic Componants: These are living things found in the environment. Biotic components include producers(Green
plants, grass, green algae), consumers(Animals like Cow, Deer,
Rabbit, Rat, Snakes,
Camel, Fox, Tiger, Lion etc. Insects like grasshoppers, birds like hawk etc)
and decomposers(A Bacteria, fungi, earthworm etc.).
• The
ecosystems are parts of nature where living organisms interact amongst
themselves and with their physical environment through the exchange of energy
and recycling of the nutrients. For
example forest ecosystem, pond ecosystem, Desert ecosystem ,Cropland ecosystem
etc.
• Thus,
any ecosystem involves complex relationship between soil, climate, plants,
animals and Microbes . A small pond of water forms an ecosystem while the Earth
as a whole may form ecosystem.
5. Biosphere• Biosphere is the sphere of life.
• The
biosphere found in the lithosphere, hydrosphere and atmosphere.
• It
is also called as Ecosphere.
• Biosphere
is formed of biotic componants. It consist of plants, animals and human beings
of the Earth.
• Biosphere
is the sum total of ecosystems on the Earth.
Subdivisions of Ecology
Ecology is broadly
divided into 2 main subdivisions Namely,
Autecology
and Synecology.
1. Autecology
• It
deals with the study of individual organisms or individual species in relation
to environment.
• The
term Autecology Was coined by Kirchner and Schroter (1902).
• The
study of autecology includes life history, behaviour, home range, population
dynamics of the individual organisms Or species in relation to environment.it
is also called species ecology.
• Ithas
great significance in economic biology such as fish culture, apiculture,
poultry, forestry etc.
• Its
study is import to soil conservation and wild life management.
• It
is experimental and inductive.
2.
Synecology
• It
deals with the study of groups of organisms,which are living together as a unit
in relation to environment.
• It
includes study of community and ecosystem.
• It
deals with the study of deserts, forests,Pond ecosystem etc.
• It
is philosophical and deductive.
• It
is largly descriptive.
• This
term was coined by Kirchner and Schroter in 1902.
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