A keystone species is a species within an ecosystem that influences most all other species in that system. If a keystone species is removed from the system, the system will either collapse or the removal will cause a dramatic change in the species composition of the system. Use the link below to access the ISEE Exchange website to explore a systems model related to the removal of the wolves, a keystone species in Yellowstone National Park.
Click on the paw to open the model and read the background of the story. Next, explore the box-and-arrow type model of the effect of wolves on vegetation in Yellowstone National Park.
Summarize the cause-and-effect model in words, including the effect on other animals and ‘ecosystem’ or ‘land health’.
- What would happen to a system if wolves are removed from it?
Next, explore the box-and-arrow model.
- What is the connection/relationship between wolves and moose & elk?
- How did the removal of wolves from Yellowstone change the behavior of the elk and moose?
- What is the indirect effect of wolves on the beaver population?
- Why does this happen?
- How are birds in the system affected?
- How does the decline of beavers lead to a decline in aquatic insect populations?
- What did the extermination of wolves affect the ‘health’ of rivers?
- How did the presence of wolf kills (carrion) affect other animals?
- How did reintroduction of wolves change the bison and elk behavior?
- How did this affect the vegetation along rivers?
- How did this affect the beaver population?
- Why do you think we refer to wolves as ‘keystone species’ to Yellowstone?
- What is a ‘keystone species’?
Finally, follow this link How Wolves Change Rivers to watch the following video provide by Sustainable Human for more talking points: