Ecosystem and its structure and functions.

1. STRUCTURE AND FUNCTION
OF AN
ECOSYSTEM
BY
ABHISHEK GARG

2. • An ecosystem is a community of living
organisms in conjunction with the
nonliving components of their
environment, interacting as a system
• Ecosystem consists of two Words :
Ecosystem
Eco Environment
System Interaction

3. • According to E.P.Odum, an American ecologist, the
ecosystem is the basic functional unit of organism
and their environment interacting with each other
and with their own components.
• e.g. Grassland, Forest, Aquarium, Pond, Lake, River
and Ocean.
Grassland Ecosystem Forest Ecosystem Ocean Ecosystem

4. Ecosystem
Abiotic
non-living
Eg. soil,
water, light,
inorganic
nutrients and
weather
Biotic
living
Eg. producers
and
consumers

6. BIOTIC LIVING
Biotic Resources are based on living organisms. These are obtained from
the biosphere. E.g Consumers,Producers and Decomposers.
Consumers: Producers are any kind of green plant. Green plants make
their food by taking sunlight and using the energy to make sugar.
Producers :Consumers have to feed on producers or other consumers
to survive. Deer are herbivores, which means that they only eat plants
(Producers). Bears are another example of consumers.
Decomposers: Decomposers are the garbage men of the animal
kingdom; they take all the dead animals and plants (consumers and
decomposers) and break them down into their nutrient components so
that plants can use them to make more food.

8. ABIOTIC COMPONENT
• In Biology and Ecology abiotic components or abiotic factors are those
non-living chemical and physical parts of the environment that affect
living organisms and the functioning of ecosystems.
• These are obtained from the lithosphere. E.g : soil, temperature,
humidity.
• Habitat is considered as abiotic componenet,
• A Habitat is an ecological or environmental area that is inhabited by a
particular species of animal, plant, or other type of organism

10. Function of Ecosystem
The components of the ecosystem
are seen to function as a unit when
we consider the following aspects:
•Productivity
•Decomposition
•Energy flow
•Nutrient cycling

11. PRODUCTIVITY
• Productivity - The rate of biomass production is
called productivity.
• Gross primary productivity - The rate of
production of organic matter during
photosynthesis is called gross primary
productivity.
Gross PP (GPP) = total energy fixed
Secondary productivity – The rate of formation
of new organic matter by consumers is called
secondary productivity .

12. • The breakdown of complex organic matter into
inorganic substances like carbon dioxide, water
and nutrients and the process is called
decomposition.
Steps in decomposition
Fragmentation
Leaching
Catabolism
Humification
Mineralization

13. • The flow of energy is one way
direction from producer to consumers,
and ends in decomposition process.
• However, a part of the energy is lost as
heat and agrees with the phenomenon
of second law of Thermodynamics.

14. NUTRIENT CYCLE
• A nutrient cycle (or ecological recycling) is the movement and
exchange of organic and inorganic matter back into
the production of living matter.
• The process is regulated by food web pathways
that decompose matter into mineral nutrients.
• Nutrient cycles occur within ecosystems.

15. NUTRIENT CYCLE