2. Eco System Definition and Concept, Structure
Transcript of 2. Eco System Definition and Concept, Structure
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- Structure and Function
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Ecology and Ecosystem
The term Ecology was coined by Earnst Haeckel in 1869.
Derived from the Greek words
Oikos- home
logos- study
Deals with the stud of or anisms and interactions with
their surroundings.
The surroundings or environment consists of other living
organ sms ot c an p ys ca a ot c components.
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I. An ecosystem is a group of biotic communities of species
interacting with one another and with their non-livingenvironment exchanging energy and matter.
II. An ecos stem is an inte rated unit consistin of
interacting plants, animals and microorganisms whose
of their biotic and abiotic structures and functions.
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ECOSYSTEM STRUCTURE & FUNCTIONECOSYSTEM STRUCTURE & FUNCTION
BIOTICBIOTIC ABIOTICABIOTIC FUNCTIONALFUNCTIONAL
ProducersProducers PhysicalPhysical ChemicalChemical Food chains &WebsFood chains &Webs
ConsumersConsumers Light IntensityLight Intensity Energy FlowEnergy Flow
DecomposersDecomposers emperatureemperature
yc ng oNutrients
yc ng oNutrients
Atmosphere/windAtmosphere/wind
ProductivityProductivity
FireFire
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STRUCTURAL FEATURES
.
Includes plants, animals and microorganisms
Status in the ecosystems
The biotic com onents include
(a) Producers:
Primarily green plants, also include some kinds of microbes
synthesize their food by the process of Photosynthesis (Blue green algae,
cyanobacteria)
Also called as Photo autotrophs (auto=self; troph=food, photo=light).
Some microorganisms produce organic matter through oxidation of chemicals
known as chemosynthetic organisms or chemoautotrophs Ex: Sulphur bacteria
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Different colors around the edge of the pool come
y s a a v atemperatures and acidity.
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(b) Consumers
.
ii. Consumers include the following types:
Herbivores lant eaters :
Feed directly on producers
also known as primary consumers.
e.g. rabbit, insect, man.
Carnivores (meat eaters)
They feed on other consumers
If they feed on herbivores they are called secondary consumers
(e.g.frog)
If they feed on other carnivores they are known as tertiary
carn vores consumers.
(snake, big fish etc.)
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Omnivores
They feed on both plants and animals(Producers and consumers)
e.g. humans, rat, fox, many birds.
Detritivores (Detritus feeders or Saprotrophs)
They feed on dead organisms
wastes of living organisms and partially decomposed matter e.g.
beetles, termites, ants, crabs, earthworm, etc.
(c) Decomposers
Derive their nutrition b breakin down the com lex or anic
molecules to simpler molecules
organic compounds
Various bacteria and fungi are decomposers
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Herbivores Carnivores
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Detritivores
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ABIOTIC COMPONENTS OF ECOSYSTEM
Light Intensity
The radiant energy from the sun is the basic re uirement for the
existence of life on the earth.
This source of energy is of fundamental importance to the
photosynthetic production of food by plants
Light Intensity is not a lethal ecological factor
Illumination or Light intensity is measured in lux
The life on earth is related to the following radiations
i. Infra-red radiation
ii. Visible light
. trav o et ra at on
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Temperature The essential and changeable environmental factor.
Penetrates into every region of the biosphere and influences
all forms of life
Causes increasing or decreasing some of the vital activities
a. behaviour
b. metabolism
c. Reproduction
d. death.
Optimum temperature or the optimum range of temperature.
Organisms react to any rise or fall of the optimum temperature range
Temperature is a measure of the intensity ofheat
Expressed as degrees on either the Fahrenheit or Celsius scale
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Precipitation.
The moisture falling on an area in liquid, or frozen form
Includes all moisture that comes to earth in the form of rain, snow, hail and dew.
e c e source o so wa er
Water cycle or Hydrological cycle
, ,
Result of the cooling and condensation of water vapour at high altitudes.
The low tem erature at hi h altitudes cools the air which ets saturated and
loses its water-holding capacity.
As the temperature starts falling, the water vapour condenses and falls as rain
due to gravity.
Depending on the environmental conditions, precipitation falls as hail, snow or rain
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Fire
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More common in drier habitats than the wet.
Li htenin is the commonest natural cause of fire initiation.
Our earths surface is hit by lightening every second in one or
another part of the globe and many of these are of great magnitude.
Falling rocks and dried woods
Volcanoes
Imp role in mineral and elemental recycling
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WIND FACTOR
The strong moving current of air is
An important ecological factor of the atmosphere
Transpiration
aus ng severa ypes o mec an ca amage
Dissemination of pollen, seeds and fruits
The pressure differences are mainly due to differential heating of atmosphere
Air enerall moves from oles towards e uator
Formation of cyclones, tornados, etc
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