Download Carrying Capacity and Limiting Factors

Carrying Capacity and
Limiting Factors
1)
Objectives:
Define limiting factor, tolerance range and carrying
capacity
2) Describe the limiting factors of an ecosystem
3)
Explain how these factors affect the carry
capacity of an ecosystem
 All
ecosystems have a maximum
population that it can sustain. The
maximum population that an
ecosystem can sustain is called the
carrying capacity.
This means that there is a maximum
number of plants and animals that can live
in a certain place.
 The carrying capacity of an ecosystem is
determined by the limited natural
resources in an area.

–
–
–
–
Space
Food
Sunlight
Water
A
population will grow if there are
more resources than are needed.
However, if there are too many
plants or animals then there will not
be enough resources and plants and
animals will begin to die.
 Any
factor that restricts the growth
of a population is a limiting factor.
 Limiting factors can be both biotic
and abiotic.
 Forest
Ecosystem:
(Terrestrial Ecosystem)
When there are only a few rabbits in the area the ecosystem is sustainable.
 If
the rabbit population grows too
much….
The rabbits eat the grass and other
small plants. The growth of grass and
plants is limited by the amount of
sunlight, space, and nutrients that are
available. These factors do not change
because the rabbit population
increased.

The forest will not grow more grass
and plants… so there will not be enough
food for all of the rabbits. If there is not
enough food the rabbits will starve.

 The
rabbit population will return to a
stable number.
Tolerance Range

The range of conditions in which a species
can live is called its tolerance range.
For example fish can survive in water over
a range of pH values. When a species is
living at one of the extreme ends of that
range, many will experience stress and
the population will decrease; if the species
is living in conditions that are optimal then
the population will be higher.
Types of Limiting
Factors
 Abiotic
Factors: Abiotic limiting
factors include things such as
temperature, light, soil, and water.
(Factors that affect where a species
can live, these are the non-living
factors)

Abiotic factors
determine if a
species can live in
an ecosystem.
– Ex: Polar bears
have adapted to
live in cold
environments and
would not be able
to survive in a
much warmer area.
 Biotic
Factors: Biotic limiting
factors include things such as
competition for resources, predators
and parasites. (Factors that affect a
species success in an ecosystem,
these are the living factors)

Biotic Factors
determine the success
of a population in an
ecosystem.
– Ex: Bobcats will hunt
and eat rabbits. The
size of a rabbit
population is limited by
the number of bobcats
that are hunting and
eating the rabbits.
Copy an complete this table using p. 54 of your text
book.
Biotic Limiting
Factor
Competition
Affect
Affect
Biotic Limiting
FactorWhen two animals compete for the same resource, such as food or
Competition
Predation
Predation
Mutualism
Parasitism
Mutualism
Commensalism
Parasitism
water.
Ex: Both foxes and owl eat mice. If there are not enough mice then
either the fox or the owl population will decrease.
When one species feeds on another.
Ex: Frogs eat flies. The size of the fly population will limit the size of
the frog population because it is a food source.
When two individuals benefit from one another.
Ex: Clownfish live in sea anemones. The sea anemone provides a safe
protected home for the clownfish and the clownfish chases away other
fish that would eat the tentacles of the sea anemone.
When one organism live off of or inside (feeds off of) another
organism.
Ex: Tapeworms live inside cats and dogs, eating any food that they
consume and making the animal sick
When one individual benefits and the other is not harmed, but does not
benefit either.
Ex: Birds that live near livestock (cows), when the cows walk they
disturb small insects that begin to fly around, this makes it easier for
the birds to catch the insects.
Commensalism
 Complete
the handout