*Energy*
in
Ecosystems
Producers- an organism that
uses energy from the sun to
produce their own food.
Producers are the source of all
food in an ecosystem.
Consumers-
organisms
that must
consume
other
organisms
because
they cannot
make their
own food
Primary
Consumers-
Organism that
gets its energy
from producers
(plants)
Secondary
Consumer-
a consumer
that gets
its energy
from other
consumers.
Example: Mouse
(consumer of grass)
gets eaten by a cat
Tertiary Consumer- a high level
consumer (usually a top predator
in an ecosystem). Example: Insects
(primary consumers) are eaten by frogs (secondary
consumers) frogs are eaten by jaguars
Quick Review- Types of
Consumers
Herbivore- eat only plants
Carnivore- eat only meat
Omnivore- eat meat and plants
Scavenger- eat dead
organisms
Decomposers- breakdown waste and
other dead organisms and return raw
materials (carbon, nitrogen, oxygen)
to the ecosystem.
Decomposers
Decomposers act as nature’s recyclers.
If an ecosystem did not have
decomposers, the raw materials of life
would be wasted rotting in the bodies of
dead organisms. Luckily decomposers,
such as bacteria and mushrooms fulfill
their need for energy by decomposing
the bodies, and at the same time return
simple molecules of oxygen, carbon, and
nitrogen to the environment.
Since all organisms have a limited
lifespan, all food chains and webs end
with decomposers.
Food
and
Food
What is a chain?
Food chain- a
series of
events
where one
organism
eats
another to
obtain
energy. There
are normally
three to five
links in the
chain.
Food Chains
The first organism in a food
chain is always a producer
(grass). The second
organism feeds on the
producer and is called a
first-level consumer or
primary consumer (mouse).
The secondary consumer
(snake) feeds on the
primary consumer. The
tertiary consumer feeds on
secondary consumer.
The arrows always point in
the direction that the energy
is flowing, or to the
organism that is consuming
the energy.
What is a web?
Food web- many
overlapping
food chains
in an
ecosystem.
In a food web you
can see how
everything is
connected to each
other.
Food Web
A food chain only shows
one possible path energy
can travel. Just as you
do not eat the same thing
every day, neither do
many organisms. Most
producers and
consumers are a part of
multiple food chains.
Organisms can play
different roles in different
food chains. For
instance, an omnivore
such as the grouse is a
primary consumer when it
eats berries and a
secondary consumer
when it eats butterflies.
Energy Pyramid
Energy Pyramida diagram that
shows the
amount of
energy that
moves from one
feeding level
to another in
a food web.
The
further along the food chain
you go, the less food (and hence
energy) remains available.
This
is why it appears like a
“pyramid”
Energy Pyramid