1. Chapter 3 - Ecosystems

2. 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.

3. Living & Nonliving Parts of Ecosystems
Living Parts – animals, plants, fungi, protists, and bacteria
Nonliving Parts – air, water, soil, sunlight, climate, and landforms

4. Ecosystems There are many different kinds of ecosystems.
Some examples –
Desert
Grassland
Tundra
Forest
Tropical Rain Forest
Coral Reef
Ponds

5. Desert
Arizona – A Desert Ecosystem Video

6. Grassland

7. Tundra
Tundra Video

8. Forest

9. Tropical Rain Forest
Rainforest Video

10. Coral Reef
Coral Reef Video

11. 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

12. Community
The different populations that interact with each other in the same area form a community.

13. 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.

14. 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.

15. 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.

16. 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?

17. Lesson 2 – Energy Flow in Ecosystems
Every living thing needs energy. Energy in an ecosystem is passed from one organism to another.

18. Producers
Producers are organisms that can make their own food.

19. Consumers
Consumers are organisms that cannot make their own food.

20. 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

21. Herbivores

22. Carnivores

23. Omnivores

24. 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.
aphic.com/ngexplorer/0309/ quickflicks/

25. 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.

26. 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.

27. 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?

28. 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.

29. 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.