Natural Events and Human Activities Cause Changes in Ecosystems Grade 7 Science Unit 1 Natural Events and Human Activities Cause Changes in Ecosystems Chapter 3

The Changing Ecosystem Have you ever noticed changes in the ecosystems around you? When? What were the changes like? Do you know what caused the changes?

The Changing Ecosystem

What do you think is happening here?

Succession Succession: A natural change of the ecosystem. The process where a biological community changes over time. These changes may be slow and hard to see over short time periods.

Pioneer species: the first species to live an ecosystem during succession. Example: lichens. Climax community: the final community of succession in an area. It doesn’t change for many years. Example: Balsam fir forests

2 Types of Succession 1. Primary Succession: Takes place in an area with no soil Examples: bare rocks, sand dunes, and cooled lava

Primary Succession

Flow Chart Create your own flow chart of Primary succession Start with bare Rock! Have small plants first Finally have a climax community!

2 Types of Succession 2. Secondary Succession: The process where an ecosystem changes after it has been disturbed. Example: A forest changing after a fire. **The re-growth of a community.

Flow Chart 2 Create your own flow chart of Secondary succession Start with a full ecosystem Have a natural or human change Have growth of small organisms Finally have your climax community!

Succession Video!

Discussion... Read p. 70-1 Succession can have environmental changes such as... 1.Soil composition 2.Plant types 3.Animal types 4.Amount of light Explain

Review Questions: Page 73 Q’s: 1, 2, 6 & 8.

“The Two Centimeter Forest” Core STSE “The Two Centimeter Forest”

The Human Impact... How do you think we have impacted our environment? 1.Harvesting resources 2.Habitat loss/ destruction 3.Introduced species 4.Pollution

Harvesting Resources We are Removing resources from ecosystems These resources may not return and may be needed by other animals

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

Introduced Species Species that have spread beyond their natural range into new locations as a result of human activities. They can take the niche of natural populations and out-compete them. Also called alien, exotic or non-native species

Ex. Of Introduced Species in NL Moose 1904 (competes with caribou) 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

Endangered Species of Newfoundland & Labrador Pine marten Wolverine Piping plover Eskimo curlew Long’s braya Barrens willow

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

Review Questions: Page 85 Q’s: 2, 5, 9 & 13.

Humans can harm the environment Are we doing anything to help? Conserving habitats! But – it’s not good for everyone…

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

Journal Entry – Take a Stand! A Conservation group wants to protect a pond forest area. What are two reasons people would want this conservation area? What are two reasons people may Not want this conservation area? Do you think they should protect the area?

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

Groups Interested in Protecting the Environment... National Examples: Parks Canada Canadian Native Federation Nature Conservancy of Canada David Suzuki

Groups Interested in Protecting the Environment... International Examples: Friends of the Earth World Wildlife Fund Ducks Unlimited

Website Activity

Chapter 3 Review Questions: Page 94-95 Q’s: 1, 6, 8, 10, 13 & 14.