1. Healthy Ecosystem A healthy ecosystem is composed of:
Producers Consumers Decomposers

2. Biodiversity
Biodiversity maintains the health of the earth and its people.
It provides us with food and medicine and contributes to our economy.
It tells us a lot about the health of the biosphere.
The greater the variety of species, the healthier the biosphere.
SPEAKER’S NOTES:
Biodiversity maintains the health of the earth (fill in the next blank) and its people.
It provides us with food and medicine and contributes to our economy. For example, we use plants and animals for food and medicine and we can harvest plants and animals and sell them to make money. In Manitoba, the fishing industry contributes $150 million annually to our economy.
Biodiversity tells us a lot about the health of the biosphere. The greater the variety of species, the healthier the biosphere is. Why is this? (pause, have students brainstorm answers).
[Possible answers]
more species = more links in food chains/webs = more stable
more plants = more food for other animals (more oxygen too)
more genes = better chances for survival through adaptation
a variety of ecosystems = more habitat for different species.]

4. Sustainable Ecosystems

5. Sustaining an Ecosystem
If you are healthy, you will probably live a long life. The same thing applies to ecosystems.
A healthy ecosystem can sustain itself and stay intact (or stable) for a long time.

6. People have a responsibility to regulate their impact on the sustainability of ecosystems in order to preserve them for future generations

7. Ecosystems are dynamic and have the ability to respond to change, within limits, while maintaining their ecological balance.

8. Food Web
A pictorial representation of the feeding relationships among organisms in an ecosystem
Consists of various food chains

10. The more links in a food web, the more stable it is.
SPEAKER’S NOTES:
Removing one link from a food web that has many links does not affect it as much as if there were very few links.
The more links in a food web, the more stable it is.

11. The Niche
A niche is the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions

12. NICHE No two species can share the same niche in the same habitat.
Different species can occupy niches that are very
similar.

13. Community Interactions
When organisms live together in ecological
communities, they interact constantly.
Community interactions, such as competition,
predation, and various forms of symbiosis,
can affect an ecosystem.

14. Community Interactions/ Competition

15. Other factors that affect population growth
Limiting factor- any biotic or abiotic factor that restricts the existence of organisms in a specific environment.
EX.- Amount of water
Amount of food
Temperature

16. What is a Limiting Factor?
Populations would continue to increase if they had all of the resources they require in unlimited amounts, but there are always factors that limit their increase.
Limiting factors control
population growth.

17. What is Carrying Capacity?
Because of these limiting factors, each ecosystem has a finite capacity for growth connected to its carrying capacity.

18. What is Carrying Capacity?
Carrying capacity is the number of individuals of a species that an ecosystem can support.

20. Ecological Succession
Ecosystems are constantly changing in
response to natural and human
disturbances.
As an ecosystem changes, older inhabitants
gradually die out and new organisms
move in, causing further changes in the
community.

21. This series of predictable changes that occurs in a
community over time is called ecological
succession.
Sometimes, an ecosystem changes in response to an
abrupt disturbance.
At other times, change occurs as a more gradual
response to natural fluctuations in the environment.

22. Primary Succession On land, succession that occurs on surfaces where
no soil exists is called primary succession. For
example, primary succession occurs on rock
surfaces formed after volcanoes erupt.
The first species to populate the area are called
pioneer species

23. Primary Succession

24. Secondary Succession Components of an ecosystem can be changed by
natural events, such as fires.
When the disturbance is over, community interactions tend to restore the ecosystem to its original condition through secondary succession