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What Drives Variation in the Critical Zone?

A Case Study in the Southern Sierra Nevada

HS-ESS2-2 Earth’s Systems

Analyze geoscience data to make the claim that one change to Earth's surface can create feedbacks that cause changes to other Earth systems

MS-ESS2-2 Earth’s Systems

Construct an explanation based on evidence for how geoscience processes have changed Earth's surface at varying time and spatial scales

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Activity Outline

  1. Variation Across the Sierra - Demo

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  • Variation in the Mid Elevation “Sweet Spot” - Small Group Brainstorm & Research

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  • Variation in the “Sweet Spot” Cotd. - Integrating BCZN Work

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  • Conclusions & Ranking

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Looking for Patterns: Across the Elevation Gradient

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Looking for Patterns: Across the Elevation Gradient

What are some factors that might explain the variation in vegetation cover across the elevation gradient?

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  • Precipitation
  • Human activity
  • Temperature
  • Bedrock type
  • Wildlife
  • Fire

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Looking for Patterns: Across the Elevation Gradient

Rock Type

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Looking for Patterns: Across the Elevation Gradient

Precipitation

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Looking for Patterns: Across the Elevation Gradient

Temperature

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A “Sweet Spot” in the CZ

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A Zoomed-In Look at the Elevation “Sweet Spot”

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Variation in the Sweet Spot

  • Look at the vegetation cover map. What do you notice about it? What factors can help start to explain the variation in vegetation? `

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  • Then, grab the geologic & climate maps. Compare them to what you see in terms of vegetation. Do you notice any patterns? Consider what might be causing them. Can you formulate a hypothesis(es)?

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Research: 10-15 minutes

Take some time to research what you’ve noticed from the maps. Can you find evidence to support your initial thoughts?

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Some key words/phrases you might consider:

  • Vegetation cover
  • (southern) Sierra Nevada
  • Rock type/bedrock composition
  • Precipitation
  • Snowmelt

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Bringing Out Papers

On the front table, you’ll see two papers: Callahan et al. (2022) and Hahm et al. (2014)

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Read through the highlighted portions of those papers and feel free to ask Jorden, Lily, Natalie, or Rachel any questions you may have!

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Conclusions

Drawing on the papers & resources you found on your own, list & rank three (3) things that drive variation in the mid-elevation zone of the Sierra.

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Your rankings should be based on whatever your group feels is the most important

eg: most affected by climate change, most impact on ecosystems, most important to human activity

Then, present your rankings to the larger group!