An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. These biotic and abiotic components are linked together through nutrient cycles and energy flows.

1. SHRI
SHANKARACHARY
A MAHAVIDYALAYA
JUNWANI,BHILAI

3. SYNOPSIS
1. INTRODUCTION
2. DEFINATION
3. SIZE OF ECOSYSTEM
4. COMPONENT OF ECOSYSTEM
5. TYPES OF ECOSYSTEM
6. AQUATIC ECOSYSTEM
FRESH WATER
MARINE WATER

4. 7. FOOD CHAIN & TYPES OF FOOD CHAIN
8. FOOD WEB
9. ECOLOGY PYRAMID
10. FUNCTION OF ECOSYSTEM
1.INTRODUCTION:- The term ecosystem was
given by a British ecologist A.G. Tansley in the year
1935. The biotic components of any ecosystem
include the producers, the consumer & the
decomposers. Each of these components is
composed of species population.

5. 2. DEFINATION:- “The basic fundamental unit of
ecology which includes both the organisms & the
non-living environment each influencing the
properties of the other & each is necessary for the
maintenance of life”.
3.SIZE OF ECOSYSTEM:-An ecosystem may exist
in a drop of water or on a single tree to ocean or
whole forest area. Large natural ecosystems like
forest ecosystems, ocean ecosystems etc. are
called biome. Earth as a whole also occurs as an
ecosystem. The abiotic & biotic components
interact upon it & bring about the various changes
on it.

6. 4. COMPONENTS OF ECOSYSTEM:-
According to legend ecologist Odum(1969),
an ecosystem is functionally formed of 2 main
components a) Abiotic comp. b) biotic comp.

7. 5. TYPES OF ECOSYSTEM:- As it has been stated
earlier the ecosystem may be large, as large as
world or as small as a drop of water.

8. 6. AQUATIC ECOSYSTEM:-Ecosystem found in
water is called aquatic ecosystem. It is of two
types:
 FRESH WATER ECOSYSTEM:- Ecosystem of non
marine water is called fresh water ecosystem.
EXAMPLE:-
POND ECOSYSTEM
Ponds & lakes are stationary fresh water bodies
occurring on land in almost all types of biomes.
Ponds are small & shallow with a size less then one
hectare & a depth of less then 2m, whereas lakes
are larger & deeper.

9. COMPONENTS OF POND ECOSYSTEM:-In a
typical pond ecosystem following components are
found:
1) BIOTIC COMPONENTS:- There are following
types of biotic components in a pond ecosystem:
a. Producers:- Green plants are producer part of
the pond ecosystem. The surface of any pond may
contain Spirogyra, Anabaena, Oedogonium,
Oscillatoria algae, unicellular plants like Volvox,
Desmids, Diatoms, Chlamydomonas.etc. This
Green vegetation of pond ecosystem is called as
phytoplankton.

10. b. CONSUMERS:-They feed on Producers directly or
indirectly . It is of following categories:
 Primary consumers:- Varied forms of
Zooplanktons are found in the water surface. Most
of them are unicellular protests, such as Amoeba,
Paramecium whereas some are multicellular
crustaceans, such as Daphnia, Cyclops, etc.
 Secondary consumers:-They feed on primary
consumers e.g., big fishes, water snakes etc.
 Tertiary consumers:- They feed on secondary
consumers e.g., Kingfisher, Cranes, omnivorous
man, etc.

11. c) Decomposers:-Various types of micro-organisms
e.g., Bacteria, fungi etc. are also present in the
pond water which are called decomposers. These
organisms attack dead bodies of producers &
consumers & convert complex organic compounds
into simpler inorganic compounds. These free
elements again return to the water of pond & are
re-utilized by producers in their nutrition & in this
way ecosystem goes on.
2) ABIOTIC COMPONENTS:-The gases like ,
etc. & other inorganic elements are dissolved in
pond water. Some abiotic components are found

12. on the bottom of the pond. These substances are
utilized by the green plant of the pond to
manufacture the food materials which is essential
for different organisms.

13.  MARINE WATER ECOSYSTEM:- It is found in
ocean, sea etc.
EXAMPLE
SEA ECOSYSTEM

14. 7.FOOD CHAIN:-The energy containing molecules
produced by green plants are the source of energy
food, for other organisms i.e., herbivores to top
consumers. It can be defined as “The
unidirectional sequence of organisms in which
energy flows in the form of food from the
organism to another organism through the process
of eating & being eaten”. Such a unidirectional
flow of food from one trophic level to another is
called food chain.
TYPES OF ECOSYSTEM
There are three types of food chains occurring in
nature :

15.  Predator food chain:-It starts with herbivores &
goes from smaller to large predators. It includes
herbivores as the primary consumers & predator
at the secondary & tertiary consumers but the size
of the predator increase at each level in the food
chain.
Example:- * Phytoplankton Zooplankton Fishes
* Grass Rabbit Lion/Tiger
* Grass Rat Kite
* GRASS Grasshopper Frog Snake Kite
 Parasitic food chain:-It also starts from green
plants which prepare organic food photosynthetic

16. From here they proceed to herbivores & then to
parasites & finally to hyperparasites. In other
words, they proceed from larger to smaller
animals.
Saprophytic food chain:-These organisms ingest
& digest the dead organic materials. Some amount
of energy is trapped & the remainder is excreted in
the from of simple organic compounds. These are
again used by another set of detritivores till the
conversion into elemental form i.e., & water.

17. FOOD CHAIN
GRASSLAND ECSYSTEMPOND ECOSYSTEM

18. 8. FOOD WEB:-In nature the food chain are
perhaps never linear or very rarely linear. They are
interrelated & interconnected with one another. At
each trophic level there is a great diversity of
organisms. Thus, every organism has ample choice
for its food, this is why several food chains operate
simultaneously in an interlinked manner which is
collectively known as food web.
Thus, the food web is a description of feeding
connections between the organisms which make
up a community.

20. 9. ECOLOGY PYRAMIDS:- In food chain of
ecosystem various food levels are present ranging
from primary producers to top carnivores. Each
food level of food chain is called a ‘step’ & they are
interrelated to each other providing a definite
functional state of trophic level of an ecosystem.
The relationship among the various trophic levels
of a food chain can be expressed on the basis of
individual number, biomass & energy flow
representation by means of graphic diagrams is
called ecological pyramid.

21. ECOLOGY PYRAMID:- POND

22. 10. FUNCTION OF ECOSYSTEM:-
 Flow of energy from one component
to the other component.
 It uses C, H, O, Ca, N, Mg, Zn, Fe.. Etc
to convert them into carbohydrate,
protein, nucleic acids fats etc.
 Also known as DYNAMICS OF
ECOSYSTEM.