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Modeling Trophic Cascades

Image of niches from the activity

Topic

  • Ecology
  • Communities
  • Ecosystems
  • Scientific Skills & Literacy
  • Visual & Physical Models

Resource Type

  • Activities
  • Card Activities

Level

High School — GeneralHigh School — AP/IBCollege
Saved By
39 Users
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Description

In this activity, students model trophic cascades using cards of organisms from seven different habitats. The activity is designed to illustrate the species relationships in a food chain and the effect of predators on the trophic levels below.

Trophic cascades have been described in numerous ecosystems, ranging from kelp forests of the Pacific Ocean, to arctic islands, to Central American jungles, to salt marshes. They occur when predators reduce the abundance or change the activity of their prey, thereby allowing species in the trophic level below to increase in number. These indirect effects by the predator can trickle down (or cascade) to many lower levels of the food chain. In a classic example, sea otters protect kelp forests by controlling the abundance of urchins that graze upon the kelp. In the absence of otters, urchins consume most of the kelp and negatively affect other organisms that live in kelp forests.

This activity complements the concepts explored in other BioInteractive resources, including the Exploring Trophic Cascades Click & Learn and the short film Some Animals Are More Equal than Others: Keystone Species and Trophic Cascades.

The “Card Images” ZIP file contains individual image files for the cards used in this activity that can be used in the classroom, particularly in online courses. A document within the ZIP file contains suggestions for their use. These card images are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) license. We would ask that you attribute these to BioInteractive and not use them for commercial purposes.

Student Learning Targets

  • Arrange organisms according to trophic level in a variety of different ecosystems.
  • Distinguish between direct and indirect effects of organisms in their environment.
     

Estimated Time

One 50-minute class period.

Key Terms

direct effect, ecology, indirect effect, species interaction

Terms of Use

The resource is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license. No rights are granted to use HHMI’s or BioInteractive’s names or logos independent from this Resource or in any derivative works.

Accessibility Level (WCAG compliance)

PDF files meet criteria.

Version History

Date Published 05.10.17
Date Updated 01.05.21

NGSS (2013)

HS-LS2-4; SEP2

AP Biology (2019)

EVO-1.C, EVO-1.D, EVO-1.H, EVO-1.J, EVO-1.K, EVO-1.O, EVO-3.A, SYI-3.D; SP2, SP6

IB Biology (2016)

C.2

AP Environmental Science (2020)

Topic(s): 1.11
Learning Objectives & Practices: ENG-1.D, SP2

IB Environmental Systems and Societies (2017)

2.2

Vision and Change (2009)

CC5; DP3

Materials

Educator Materials (PDF) 2 MB
Habitat and Organism Cards (PDF) 4 MB
Card Images (ZIP) 40 MB

Additional Materials

  • copies of the “Habitat and Organism Cards,” printed or shared electronically 
  • (if using printed cards) chart paper or whiteboard and magnets, markers
  • (if doing the activity as a competitive game) stopwatch or timer

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