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

The Changing Ecosystem

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.

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

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

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.

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

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

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

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.

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

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

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

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.

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

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

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

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

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

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

Some environmental problems are not so easy to solve.

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

Oil Slicks/ Spills

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)

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

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.

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.