Ecological Communities

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Competition

Photo by Brocken Inaglory

All of the members of a single species that

live in an area make up a population

Buffalo

population

Rabbit

population

The populations of living things interacting in

an area are called a community.

Grassland
Community

All of the living things and the abiotic

factors in an area make up the

ecosystem.

Ecosystem

Water
Vapor

Air

Minerals

Light

In any ecosystem there are a finite

number of resources. This means that
there is a limited amount of nutrients:
examples: water, habitats and energy.

Photo by Tomas Castelazo

Photo by Edwin Olson

Photo by B. Navez

Multiple Choice

The specific environment in which all the biotic (living) and abiotic (non- factors in an area interact.

• Ecosystem

• Organism

• Struggle

• Competitive Interaction

Multiple Choice

All the members of one type of species in a specific area.

• habitat

• community

• population

• ecosystme

Multiple Choice

All of the different populations that live in a specific area.

• ecosystem

• habitat

• ecology

• community

In any ecosystem there are a finite number of
resources. This means that there is a limited
amount of nutrients: examples: water, habitats
and energy.

Photo by Tomas Castelazo

Photo by Edwin Olson

Photo by B. Navez

● Carrying

Capacity:

The maximum size
of a population due
to limited resources

● Organisms compete

for

these

limited

resources, not every
member of a species
will survive.

Carrying Capacity

The size of a population will grow until it
reaches the carrying capacity and there

are not enough resources for every
organism. When this happens, the

population will shrink as organisms die.

Carrying Capacity

In healthy populations, the number of
organisms will stay fairly constant right

around the carrying capacity.

The carrying capacity
is dependent on the
amount of water,
habitats,

nutrients

and energy available
in an ecosystem.

Carrying Capacity

When organisms of the same species compete

for limited resources, it is called intraspecific

competition.

Competition

Intra- means within

Intraspecific competition can involve

defending a territory or acquiring mates.

Competition

Photo by "Mike" Michael L. Baird

Elephant seals

fighting for mates

Photo by Brocken Inaglory

Sea anemones

competing for territory

Interspecific competition is between organisms of
two different species that have overlapping niches.

Competition

Inter- means between

Plants spread their seeds to prevent
competition within a population for

water, sunlight and nutrients.

Competition

Photo by Kobako

Photo by Zephyris

Seeds carried by wind.

Seeds carried by animals.

An ecological niche: is a description of a

population’s use of resources and response to the

environment.

Competition

Rabbit are herbivores that eat
plants. They live in burrows they
dig in the ground. They are preyed
on by several carnivores, and they
reproduces quickly which reduces
competition among predators.

Because there is a limited amount of these

resources, organisms must compete for them.

Competition occurs when organisms

share a limited resource.

Animals and plants in the desert
compete over water that is scarce.

Multiple Choice

In the graph to the right, what is the population of deer at the carrying capacity of the environment?

• 3

• 7

• 70

• 40

Multiple Choice

What happens if a population grows past its carrying capacity?

• The population keeps growing

• The population starts to die off

• The entire species will go extinct

• The carrying capacity just increases

Multiple Choice

A squirrel hides his acorns from the chipmunks for the winter.

• commensalism

• parasitism

• competition

• mutualism

Types of Niches

Populations can avoid
competition by filling

different niches. This allows
both populations to thrive.

Competition

Anole
Lizard

Different species of anole lizards live
in different areas (tops of trees, tree

trunks, bushes) to avoid

competition with each other.

Deforestation also increases competition in ecosystems
by reducing the number of habitats and producers

that are available.

Competition

Multiple Choice

What is a niche?

• The habitat that an organism lives in

• An organism’s “role” in an ecosystem

• A type of consumer

• The relationship between a producer and consumer

Multiple Choice

Something that regulates the size of a population is called...

• a limiting measure

• a limiting factor

• carrying capacity

• biodiversity

Multiple Choice

The largest number of individuals that an environment can support long term is...

• carrying capacity

• emigration

• immigration

• population density

Multiple Choice

This may cause a population to increase

• increase of food supply

• removal of predators

• removal of disease

• all of these

Multiple Choice

Deforestation_____________ the competitive ecosystem

• Increases

• Decreases

Reorder

Reorder the following levels of a food chain

• Sun

• Producer

• Primary Consumer

• Secondary Consumer

• Tertiary Consumer

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5