In several instances, human negligence has lead to the introduction of exotic species in native ecosystems. While most exotic species do not have negative consequences on the ecosystem, some become invaders, outcompeting native species and causing adverse effects throughout the food web. In this lesson, students will learn about the consequences and management techniques of invasive species, particularly those that exist in nearby or local ecosystems.
Goals:
- Students will be able to describe the impact of invasive species on native ecosystems.
- Students will be able to describe how invasive species affect the food chain in an ecosystem.
- Students will be able to identify local invasive species.
- Students will be able to explain noxious weed management techniques and when they are most effective.
Background Information/Additional Resources:
- American Institute of Biological Sciences
- Introduced Species: The Threat to Biodiversity & What Can Be Done
- Environmental Impacts of Marine Exotics
- The National Invasive Species Council
- U.S. Fish & Wildlife Service: Environmental Contaminants Program-Invasive Species
- Great Lakes Eco-Region
- Great Lakes Information Network: Non-native Invasive Species
- Invasive Species of Wisconsin
Activities:
- Weed Management Field Trip: Take a mini field trip outside (Pheasant Branch) and have students identify both common and noxious weeds. Discuss environmental effects and weed management efforts.
- An Environment Near You: Have students research a local invasive species from a climate change perspective.
Potential Student Questions and Answers
Consider putting in a worksheet, and perhaps using for a guided class discussion.
Q: How do invasive species get into ecosystems?
A: “Often humans play a part in the introduction of non-native species to ecosystems. For example, it is thought that Zebra mussels were introduced when a European cargo ship discharged ballast water into the Great Lakes. Humans may introduce exotic species for aesthetic purposes, often without considering the possibility of invasion. Also, when humans release exotic pets into the wild, there is a risk they may be invasive to the surrounding environment, such as the python in the Florida Everglades.”
Q: Are all non-native species invasive?
A: “No. After their introduction, non-native invasive species will experience an i increase in their fitness. Simultaneously, native species occupying a similar niche will experience a significant decrease in their fitness. This usually has adverse effects on the rest of the food web in an ecosystem. This chain reaction does not occur if the non-native species is not invasive.
Q: How does climate change affect invasive species?
A: “Warmer climates create more hospitable environment for exotic invaders. As climates become warmer and wetter, more non-native species may find their way to the United States and thrive there. Many species will experience an increase in range, including invasive species.”
Focus the Classroom 