CHAPTER 3 - ECOSYSTEMS

Lesson 1 – Parts of Ecosystems

An ecosystem is made of living and nonliving parts

that all work together. Every organism in an

ecosystem has a part to play.

An ecosystem is all of the living and nonliving

things in an environment and the many ways

they interact.

An ecosystem can be as large as a desert or as

small as a rotting cactus.

Living & Nonliving Parts of Ecosystems

Living Parts – animals, plants, fungi, protists, and

bacteria

Nonliving Parts – air, water, soil, sunlight, climate,

and landforms

Ecosystems

There are many different kinds of ecosystems.

Some examples –

Desert

Grassland

Tundra

Forest

Tropical Rain Forest

Coral Reef

Ponds

Desert

Arizona – A Desert

Ecosystem Video

Grassland

Tundra

Tundra Video

Forest

Tropical Rain Forest

Rainforest Video

Coral Reef

Coral Reef Video

Population

A population is all the

members of one species

that live within an area of

an ecosystem.

Desert Example –

Prairie dog population

Plant population

Community

The different populations that interact with each

other in the same area form a community.

What might be a reason for a

population decrease in a community?

The amount of food decreases. This means that the

animal will have to leave that area in search of

food.

Habitat

The area or place where an organism lives in an

ecosystem is called a habitat. A habitat contains all

the living and nonliving things an organism needs.

Niche

The specific role of an organism in its habitat is

called its niche. A niche includes the type of food

the organism eats, how it gets its food, and which

other species use the organism as food.

Adaptations also help determine an organism’s

niche.

Review

1. What is the name for all of the members of one species that live within an area of an ecosystem?

2. What is the name for all of the living and nonliving things in an environment and how they interact?

3. What is the name for the specific role of an organism in its environment?

4. What is the name for the different populations that interact with each other in the same area?

5. Why is a desert considered an ecosystem?

Review

1. Population

2. Ecosystem

3. Niche

4. Community

5. It is made up of living and nonliving things that

interact with each other. An ecosystem may be

large, like a desert, or small, like a rotting cactus.

Lesson 2 – Energy Flow in Ecosystems

Every living

thing needs

energy.

Energy in an

ecosystem is

passed from

one organism

to another.

Producers

Producers are

organisms that

can make their

own food.

Consumers

Consumers are

organisms that

cannot make their

own food.

More about Consumers

There are three different types of consumers.

Herbivores – get energy by eating only plants

Carnivores – get energy by eating only animals (meat)

Omnivores – get energy by eating plants & animals

Herbivores

Carnivores

Omnivores

A Food Chain

The sun is the main source of energy for life on earth. A food chain begins with energy from sunlight.

Producers are the next link in the chain.

Predators get energy they need by hunting and killing prey.

An animal with no natural enemies is called a top predator.

http://magma.nationalgeographic.com/ngexplorer/0309/quickflicks/

Small Things That Make a Big

Difference

Decomposers digest the waste and remains of dead

plants and animals.

Why are decomposers important to the food chain?

They add minerals and nutrients to soil, water & air.

A Food Web

Ecosystems have many food chains. The same food source can be part of more than one food chain. As a result, one food chain often overlaps other food chains.

What might happen if a population dies out? The food web will change.

Review

1. When a food chain overlaps with other food chains it is called a –

2. A food chain starts with an -

3. What is the main energy source for life on Earth?

4. What is the job of a decomposer and why is it important to the food chain?

5. What is a producer? Give an example.

6. What is a consumer? Give an example.

7. What is a herbivore?

8. What is an omnivore?

9. What is a carnivore?

10. What might happen if a population dies out?

Review

1. Food Web

2. Energy Source

3. The Sun

4. It breaks down the remains of dead organisms into minerals and

nutrients that living things can take from the soil, air, and water.

5. producers make their own food. Example: plant

6. consumers use other organisms as food. Example: roadrunner

7. consumers that eat only plants

8. consumers that eat plants and meat

9. consumers that eat only meat

10. it would affect the food chain. Animals would have to compete

more for their food because their would be less food

Lesson 3 – The Flow of Matter in an

Ecosystem

All organisms need more than energy to survive. They

also need matter in the form of minerals, oxygen, and

carbon dioxide. This matter is then returned to the

ecosystem when organisms die and decay.

Matter and energy flow through an ecosystem. Plants

use minerals from the soil and gases in the air.

Herbivores get the matter and energy they need to

form the plants they eat. Carnivores get the matter

and energy they need from the animals they eat.

Decay in Ecosystems

All living things eventually die and rot, or decay.

Decay is a very important process. Without decay,

dead organisms and wastes would pile up and

interfere with the habitats of living things.

Decaying plants and animals are helpful because

they put minerals back into the soil.