Trophic levels found on ecosystems.

1. UNIT 2
THE ECOSYSTEM

2. 2.1 BIOTIC, ABIOTIC FACTORS,
AND TROPHIC LEVELS

3. BIOTIC FACTORS
• Biotic factors are the living components that
shape an ecosystem; any organism that affects
another organism.
• Biotic components are:
– Animals
– Plants
– Bacteria
– Fungi

4. ABIOTIC FACTORS
• Abiotic factors are the non-living components
of an ecosystem, affecting the life of
organisms.
• Abiotic factors can be harmful to the
ecosystem.
• Abiotic components are:
– Temperature, light, water, soil, rocks, and human
influence.

5. WATER
Water is one of nature’s
most important things is
life. Essential to life, an
organism’s survival
depends an water. Water is
necessary for digestion and
absorption of food; helps
maintain proper muscle
tone-, supplies oxygen and
nutrients to the cells; rids
the body of water; and
serves as a natural air
conditioning system.

6. SUNLIGHT
The sun provides light
and warmth and it is
the energy source for
almost all ecosystems
on Earth. Sunlight
powers
photosynthesis by
plants, the main
producer in most
terrestrial ecosystems.

7. TEMPERATURE
Most life exists within a
fairly narrow range of
temperatures, from about
0 C to about 50 C. Few
organisms can maintain an
active metabolism below 0
C for long, and most
organisms’ enzymes are
denatured (they lose their
shape and stop working)
above 50 C. However,
extraordinary adaptations
enable certain species to
live at extreme
temperatures.

8. SOIL
Soil is the product of abiotic
forces (such as ice, rain, and
wind) and the actions of living
things (such as
microorganisms, plants, and
earthworms) on the rocks and
minerals of Earth’s crust. The
structure and chemical
makeup of soil and rock in an
area affect the types of plants
that grow there. In aquatic
environments as well, the
characteristics of underlying
sand and rock affect the type
of plants and algae that can
grow. This in turn affect the
other organisms found there.

9. OXYGEN
Oxygen is an
important component
of life. Most living
things consume
oxygen in different
forms and quantities.
Most of the oxygen
that is used in
respiration is to obtain
chemical energy from
the fats and
carbohydrates in our
food.

10. WIND
Many plants use the
help of the wind to
disperse seeds over
long distances.
Organisms disperse to
find new habitats rich
in needed resources.
Strong winds can be
very destructive.

11. TROPHIC LEVELS
• There are trophic levels within an ecosystem;
these are the feeding positions that biotic
components occupy on the food chain.
• The word trophic derives from the Greek
trophe referring to food or feeding.
• A food chain represents a succession of
organisms that eat another organism and are,
in turn, eaten themselves.

12. TROPHIC LEVELS
• Trophic levels in a food chain are:
– Trophic level 1 – primary producers
– Trophic level 2 – herbivores or primary consumers
– Trophic level 3 – predators, carnivores which eat
herbivores or secondary consumers
– Trophic level 4 – carnivores which eat other carnivores or
tertiary consumers
– Trophic level 5 - apex predators which have no predators,
at the top of the food chain
The path along the chain forms a one-way flow along
which energy travels in the form of food.

13. TROPHIC LEVELS
1. Producers - (autotrophs) are typically plants or
algae. Plants and algae do not usually eat other
organisms, but pull nutrients from the soil or the
water and manufacture their own food using
photosynthesis. In this way, it is energy from the
sun that usually powers the base of the food
chain.
– An exception occurs in deep-sea hydrothermal
ecosystems, where there is no sunlight. Here primary
producers manufacture food through a process called
chemosynthesis.

14. TROPHIC LEVELS
2. Consumers - (heterotrophs) cannot
manufacture their own food, and need to
consume other organisms. They are usually
animals. Animal that eat primary producers,
such as plants, are called herbivores. Animals
which eat other animals are called carnivores,
and animals which eat both plant and other
animals are called omnivores.

15. TROPHIC LEVELS
3. Decomposers (detritivores) break down dead
plant and animal material and wastes and
release it again as energy and nutrients into
the ecosystem for recycling. Decomposers,
such as bacteria and fungi (mushrooms), feed
on waste and dead matter, converting it into
inorganic chemicals that can be recycled as
mineral nutrients for plants to use again.

16. TROPHIC LEVELS
• In real world ecosystems, there is more than
one food chain for most organism, since most
organisms eat more than one kind of food or
are eaten by more than one type of predator.
A diagram which sets out the intricate
network of intersecting and overlapping food
chains for an ecosystem is called its food web.

17. FIRST TROPHIC
LEVEL
The plants in this
image, and the algae
and phytoplankton in
the lake, are primary
producers. They take
nutrients from the soil
or the water, and
manufacture their
own food by
photosynthesis, using
energy from the sun.

18. SECOND
TROPHIC LEVEL
Rabbits eat
plants at the first
tropic level, so
they are primary
consumers.

19. THIRD TROPHIC
LEVEL
Foxes eat
rabbits at the
second trophic
level, so they
are secondary
consumers.

20. FOURTH TROPHIC
LEVEL
Golden eagles
eat foxes at
the third
trophic level,
so they are
tertiary
consumers.

21. DECOMPOSERS
The fungi or the
earthworms
feed on dead
matter,
converting it
back to nutrients
that primary
producers can
use.

23. Desert

24. Taiga forest

25. Temperate forest