1. Interactions Within Ecosystems Chapter 3
Grade 7 Science Unit 1
Interactions Within Ecosystems
Chapter 3

2. The Changing Ecosystem

5. Succession... A natural change of the ecosystem.
It is the process by which a biological community changes over time. These changes may be slow and hard to see over short time periods.

6. Pioneer species: the first species to inhabit an ecosystem undergoing succession. Examples include lichens.
Climax community: the final community in the process of succession that remain unchanged for many years. The balsam fir is an example

7. 2 Types of Succession... Primary Succession
Takes place in areas lacking soil (bare rocks, sand dunes, and cooled lava for example)

9. Secondary Succession
The process by which an ecosystem changes after it has been disturbed by a fire for example.
The re-growth of a community.

11. Discussion... Read p. 70-1
Succession can have environmental changes such as...
Soil composition
Plant types
Animal types
Amount of light
Explain

12. The Human Impact... How do you think we have impacted our environment?
Harvesting resources
Habitat loss/ destruction
Introduced species
Pollution

13. Harvesting Resources
The demand for natural resources has increased due to the increase in the human population.
Our technologies have enabled us to remove the resources we need.

14. Habitat Loss/ Destruction
Removing vegetation and soil removes shelter and food for animals.
Changes on land alter drainage of water which affects rivers and lakes.
See table 3.1 on p. 77

15. Introduced Species
Species that have spread beyond their natural range into new locations as a result of human activities.
Also called alien, exotic or non- native species.

16. Can have negative impacts on the environment and affect ecological processes.

17. Ex. Of Introduced Species in NL
Moose 1904
Eastern chipmunk 1962
Coyote
Snowshoe hare 1860
American mink 1934
Deer mouse
Norway rat
Masked shrew
American res squirrel 1963
Bank vole
Purple loosestrife
English ivy
Scotch broom

18. Endangered Species of Newfoundland & Labrador
Pine marten
Wolverine
Piping plover
Eskimo curlew
Long’s braya
Barrens willow
Choose one of the above and “tell its story”.
Endangered Species of Newfoundland & Labrador

19. Pollution
Substances that cause harm to the air, soil, water, or living things are called pollutants.
Can have direct and indirect impacts on the environment.
P. 82

20. Habitat Conservation Pros Cons Sustainability of resource
Preservation of biodiversity
Eco-tourism
Artificial habitats
Economic loss (job loss, etc.)
Limited human use

21. Some environmental problems are not so easy to solve.

22. The Decline in Cod Stocks Reasons?
New fishing technology
More demand
Lack of conservation
Unsustainable harvesting
p. 80-1

23. Oil Slicks/ Spills

24. Acid Rain
Caused by pollutants combining with water vapour in the atmosphere to produce acids.
The acids fall as acid precipitation.
NL is mostly granite rock. (unable to neutralize the acid)

25. Managing the Ecosystem
Ecosystems must be monitored to detect any changes. Methods may focus on the:
Physical
Chemical
Biological
Atmospheric

26. Long-term Monitoring
Occurs over a period of many years.
Important in managing species as it helps determine if the environment is changing in a significant way.

27. Groups Interested in Protecting the Environment...
Local Examples:
Protected Areas Association
Conservation Corps Newfoundland & Labrador
Shane Mahoney

28. National Examples:
Parks Canada
Canadian Native Federation
Nature Conservancy of Canada
David Suzuki

29. International Examples:
Friends of the Earth
World Wildlife Fund
Ducks Unlimited

30. Predicting Change
A goal of environmental monitoring. (ex. Climate change)
Important for planning future developments.
Environmental impact assessments are used to help make decisions prior to new development.