Plant Ecology in a Changing World
  • Topics
    • Topic Overview
    • Biomes and Climates in a Changing World >
      • Adaptation, biodiversity, and environment
      • Climate constrains plant distributions
      • Biome and climate relationships
      • Deserts
      • Grassland, savanna, and shrub biomes
      • Forest biomes
      • Alpine and tundra biomes
    • Plant adaptation >
      • Plant microclimate 1
      • Plant microclimate 2
      • Leaf energy budgets
      • Water movement through the soil-plant continuum
      • Principles of photosynthesis
      • Photosynthesis responses to light and temperature
      • Environmental stresses limit resource capture and use
      • Nutrients in the environment
      • Adaptation to environmental stress
    • Resource Allocation Changes with Environment >
      • Architecture and canopy processes
      • Plant phenology and resource allocation enhance performance
      • Leaf economic spectrum
      • Life history and reproduction
      • Defense against herbivory
      • Plant competition
    • Plant Responses to a Changing World >
      • Global changes occurring today
      • Invasive species
      • Atmospheric CO2 impacts plant
      • C3/C4 photosynthesis and climate
      • Climate change and the global carbon cycle
      • Climate warming and its impacts
    • Engineering Plant Communities >
      • Remember Utah's past and envision our future
      • Restoration ecology
      • Managed ecosystems
      • Utah urban ecology
      • Urban ecological futures
  • Assignments
    • Assignment Overview
    • Discussion
    • Problem sets
    • Ecology & Global Changes
    • Plant ecology policy
    • Defense of policy
    • Exam #1
    • Exam #2
  • Campus
    • Campus Overview
    • Grasses
    • Green infrastructure >
      • GI Overview
      • Stormwater >
        • GI 1
        • GI 2
        • GI 3
        • GI 4
        • GI 10
      • Green roof
      • Pollinator >
        • Pollinator species
    • Trees of the Wasatch
    • Shrubs of the Wasatch
    • Invasives
  • Biomes
    • Biome Overview
    • Climate diagrams
    • Vegetation sight-seeing trip
    • Biome images
  • Models
  • Lab

Page 429

Wandering through the redwood forests of northern California

Last year I was so excited. During the Fall Break I traveled to the redwood forests of northern California. I wanted to both see these wonderful coastal forest ecosystems, but I also wanted to see the locations where the"Ewoks" lived since this is the ecosystem that George Lucas used when he filmed Episode 6 of Star Wars. Well to my surprise, I came across Oxalis oregana, the redwood sorrel shown below on the left. It is an understory plant, adapted to growing in the deep shade within redwood forests. To my pleasant surprise, the leaves reoriented by transitioning from a horizontal flat position to a near vertical position when exposed to direct sunlight.
Picture
Picture
Now I wondered whether the leaf reorientation was initiated by a red-light sensor or a blue-light sensor at the base of the leaflets. Well I happened to have two filters with me on this trip. Filter #1 allowed only blue wavelengths to pass through. Filter #2 allowed only red wavelengths to pass through. Luckily I had two test tubes with me. So I cut off two redwood sorrel leaves and placed one into each of the two test tubes. Both of the leaves were horizontal. I then positioned a filter above a leaf and waited and watched.

Well, just as I thought. When the sun fleck came through, one of the leaves remained horizontal while the other leaf responded to the sun fleck and increased its leaf angle. I wonder what happened to the photosynthetic rate during this period. The sun fleck lasted 15 minutes, which is unusually long for a sun fleck.


After a few minutes in the sun, I noticed that the leaf remaining horizontal began to change from a deep green to a light green color.

I cannot wait to get home and write up these results. Cool. Really cool.

Picture
Go to page               Exam 2 data starter    428   430     431     432
Jim Ehleringer, University of Utah