Ecosystems and ChangeChapter 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

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 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

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

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

Symbiosis- is a relationship between two different organisms.

There are 3 types of symbiosis:1. Mutualism: both animals benefit2. 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

Example of Mutualism:

-The bird eats the insects on the rhino. The bird gets dinner and the rhino gets relief.

-Both benefit.

Lesson 1

Example of Commensalism:

– The barnacles on the whale eats what the whale misses.

– The barnacles benefit.– The whale is not

harmed.

Lesson 1

Parasitism: – 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

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 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

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

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

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

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 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

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

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

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

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

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

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

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.