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Cougars and Trees in a Trophic Cascade

Cougar graph from the paper
Topic
  • Ecology
  • Communities
  • Environmental Science
  • Human Population & Impacts
  • Science Practices
  • Graph Interpretation
Resource Type
  • Activities
  • Data Points
Level
High School — GeneralHigh School — AP/IBCollege
Used In
1 BioInteractive Playlists
Favorited By
15 Users
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Description

This activity guides the analysis of a published scientific figure from a study that investigated the effects of tourism on cougars and cottonwood trees in a national park.

In 1918, Utah’s Zion National Park was established to protect forests and rivers from human activity. But as more tourists began visiting the park, they displaced cougars (mountain lions), the top predator of herbivores called mule deer, from certain areas. In this study, scientists compared vegetation in areas of the park with and without cougars. The figure shows the age structure of cottonwood trees found in the park in 2015. Panel A shows trees from an area where cougars were common, and Panel B shows trees from an area where cougars were rare. The “Educator Materials” document includes a captioned figure, background information, graph interpretation, and discussion questions. The “Student Handout” includes a captioned figure and background information. The original article is also provided as a download.

The “Resource Google Folder” link directs to a Google Drive folder of resource documents in the Google Docs format. Not all downloadable documents for the resource may be available in this format. The Google Drive folder is set as “View Only”; to save a copy of a document in this folder to your Google Drive, open that document, then select File → “Make a copy.” These documents can be copied, modified, and distributed online following the Terms of Use listed in the “Details” section below, including crediting BioInteractive.

Student Learning Targets
  • Analyze and interpret data from a scientific figure. 
  • Describe how changes in one population in an ecosystem can impact other populations through a trophic cascade.
Details
Estimated Time
Within one 50-minute class period.
Key Terms

age class, bar graph, biodiversity, error bar, food chain, germination, herbivory, predator, prey, trend line

Primary Literature

Beschta, Robert L., and William J. Ripple. “The Role of Large Predators in Maintaining Riparian Plant Communities and River Morphology.” Geomorphology 157–158 (2012): 88–98. https://doi.org/10.1016/j.geomorph.2011.04.042.

Terms of Use

Please see the Terms of Use for information on how this resource can be used.

Accessibility Level

The documents for this resource meet accessibility standards in accordance with the final rule for Section 508 of the National Rehabilitation Act.
Version History
Date Published 09.10.18
Date Updated 04.30.20
Curriculum Connections
NGSS (2013)

HS-LS2-2; SEP2, SEP4, SEP5

AP Biology (2019)

ENE-1.N, ENE-4.B; SP1, SP4

IB Biology (2016)

4.1, C.2, C.3

AP Environmental Science (2013)

II.A, IV.D.3

IB Environmental Systems and Societies (2017)

2.2

Common Core (2010)

ELA.RST.9-12.7
Math.S-ID.6, Math.S-IC.4; MP2, MP5

Vision and Change (2009)

CC5; DP2, DP3

Materials
Resource Google Folder (link)
Educator Materials (PDF) 376 KB
Student Handout (PDF) 315 KB
Original Article (PDF) 2 MB
Educator Materials - Español (PDF) 496 KB
Student Handout - Español (PDF) 424 KB

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