Exploring Trophic Cascades
This interactive module explores examples of how changes in one species can affect species at other trophic levels and ultimately the entire ecosystem.
Trophic cascades refer to impacts that reach beyond adjacent trophic levels. This Click & Learn first walks students through a classic trophic cascade triggered by the loss of sea otters from a kelp forest ecosystem. Students then test their understanding of trophic cascades in four other case studies, where they predict the relationships among different species and the consequences of ecosystem changes. The case studies demonstrate how indirect effects mediated by changes in one species can broadly alter many aspects of community function.
Student Learning Targets
- Predict whether different organisms in an ecosystem have positive or negative effects on other organisms in that ecosystem.
- Predict how an ecosystem may change when a particular organism is introduced or removed, based on the evidence provided.
consumer, direct effect, food web, indirect effect, jungle, lake, producer, savanna, trophic pyramid, tundra, keystone, poster
Accessibility Level (WCAG compliance)
HS-LS2.A, HS-LS2.B, HS-LS2.C; SEP2
AP Biology (2019)
ENE-1.M, ENE-1.N, ENE-1.O, ENE-4.B, SYI-1.G, SYI-1.H; SP2
IB Biology (2016)
AP Environmental Science (2020)
Topic(s): 1.1, 1.9, 1.11
Learning Objectives & Practices: ERT-1.A, ENG-1.B, ENG-1.D, SP1, SP2
IB Environmental Systems and Societies (2017)
Vision and Change (2009)