Ecosystems and Change
Chapter 6
Lesson 1: How Do Organisms
Compete and Survive?
Lesson 2: How Do Ecosystems
Change Over Time?
Lesson 3: How Do People Affect
Ecosystems?
Lesson 1
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Population: Includes all organisms of the same
kind.
Community: A group of populations that live
together.
Competition: A contest between organisms for
things they need to survive.
Adaptation: A trait that helps an organism
survive.
Symbiosis: A relationship between 2 different
kind of living organisms.
Predator: An animals that eats other animals.
Prey: Animals that are eaten.
Lesson 1
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Vocabulary
Ecosystem include many
types of plants and animals.
All organisms of the same
kind are a population.
The prairie ecosystem has
many populations such as
rabbits, mice, daises,
insects, and birds.
Population that live and
interact together make up a
community.
The physical environment is
also part of the ecosystem.
Lesson 1
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In order to survive, a
population needs food,
water, shelter, and space.
Competition is a contest
between living organisms.
They compete for things
they need to survive.
Population often compete for
the same food. Alligators
and turtle both eat fish for
example.
Too little food leads to more
competition. Competition
limits the number of
organisms that can live in an
ecosystem.
Lesson 1
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To survive, many organisms
have developed
adaptations.
This trait may be physical,
like a tiger’s coloring.
The trait may be a way of
behaving, like a turtle
digging in the mud to get
away from the cold weather
in the winter.
Lesson 1
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Symbiosis- is a relationship between two
different organisms.
There are 3 types of symbiosis:
1. Mutualism: both animals benefit
2. Commensalism: One benefits and the
other doesn’t benefit but also is not harmed.
3. Parasitism: One organisms benefits and
the other is harmed.
Lesson 1
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Example of Mutualism:
-The bird eats the
insects on the rhino.
The bird gets dinner
and the rhino gets
relief.
-Both benefit.
Lesson 1
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Example of
Commensalism:
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The barnacles on the
whale eats what the
whale misses.
The barnacles benefit.
The whale is not
harmed.
Lesson 1
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Parasitism:
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Mistletoe sends its roots
into a tree.
The mistletoe takes
nutrients from the tree
and benefits.
The tree is harmed
because it loses
nutrients.
Lesson 1
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Animals must eat in order to live.
They must also try to escape
being eaten.
An animals that eats another
animals is a predator.
The animal that gets eaten is the
prey.
Mice and rabbits are prey for
owls.
The number of predators and
prey are closely matched.
Any chance in the numbers of
one will affect the number of the
other.
If there are too few predators, the
number of prey increases.
If there are too many predators,
the number of prey decreases.
Lesson 2
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Vocabulary
Succession: Is a gradual change in an
ecosystem.
Extinction: Is the death of all the organisms
of a species. It is extinct.
Lesson 2
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A gradual change in
ecosystems is called
succession.
Succession can take
thousands of years.
Succession can be caused
by climate change of by
organisms that live there.
An example of succession is
a herd of deer kill trees by
eating too many leaves.
The deer no longer have
food so many leave or die.
Lesson 2
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There are 2 kinds of succession:
-Primary succession: It starts with a bare rock and grows
lichens. Lichens are an organism that grow without soil. As the
lichens grow, they break down the rocks which turns into soil.
Now that there is soil, plants can grow.
Lesson 2
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There are 2 kinds of succession:
– Secondary Succession: helps restore ecosystems that have
been damaged. It often occurs after a fire or volcano.
Secondary succession takes place much more quickly than
primary succession. After a forest fire (for example) some
roots and seed survive underground and begin to grow again.
Lesson 2
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Sometimes changes in
ecosystems kill off an entire
species.
Extinction is the death of all
species.
Many organisms can adapt to
slow changes in ecosystems but
some cannot and die.
A change in the environment can
be so great that it affects many
species.
For example, most dinosaurs
became extinct many years ago
along with 70% of all organisms.
This mass extinction was
probably because of a big
change in Earth’s climate.
Lesson 3
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Vocabulary
Pollution: any waste that damages an ecosystem.
Acid Rain: a mixture of acids and rain that fall to
Earth.
Habitat: an area where an organism can find
everything it needs to survive.
Conservation: means saving and protecting natural
resources.
Reclamation: is the process of restoring a damaged
ecosystem.
Lesson 3
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Ecosystems can be
damaged by pollution.
Pollution is any waste that
can harm living things.
Pollution also damages
ecosystems.
For example, water
ecosystems can be polluted
by chemicals used on crops
and lawns.
Lesson 3
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The air can also be polluted.
Burning fossil fuels is a
major cause of air pollution.
Fossil fuels include coal, oil,
and gas.
Certain chemicals in fossil
fuels mix with water vapor in
the air.
The combination turns into
acid.
The acid falls to Earth as acid
rain.
Acid rain can damage crops,
and other plants.
It also pollutes streams, river,
lakes and can kill the
organisms that live in them.
Lesson 3
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Ecosystems can also be
damaged by changes like a
prairie being turned into a
farm.
When people fence an
ecosystem, they reduce the
size of the ecosystem for the
animals that live there.
A habitat is an area where an
organism can find what it
needs to survive.
Fencing off an ecosystem
may force animals to share
habitats with people.
Fences also make it hard for
animals to move to different
habitats.
Lesson 3
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When people cut down forests for timber,
they destroy many habitats.
Habitats are also destroyed when people fill
in wetlands in order to build houses.
Lesson 3
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Laws have been passed to
protect ecosystems.
There are rules that control
how companies get rid of
wastes.
New cars must have devices
that reduce air pollution.
Builders must show how a
project will affect the
environment before they
start the project.
Lesson 3
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People can reduce the
amount of resources they
use.
Instead of throwing things
away, people could reuse
them.
Start recycling things like
glass, plastic, and paper.
When things are recycled,
they are used to make
new things which cuts
down on the natural
resources we destroy.
Lesson 3
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Damaged ecosystems
are not always lost
forever.
Some ecosystems can
be put back to their
original condition but it
takes time and money.
This process is called
reclamation.