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

C3 and C4 grass species

On our campus, you will find both planted C3 and C4 grasses, native C3 and C4 grasses, as well as invasive C3 and C4 grass species.  Perhaps the most obvious grasses on campus are the lawns, which are predominantly Kentucky bluegrass (Poa pratensis).
Picture
One way to distinguish C3 and C4 photosynthetic pathways of leaves is with a hand lens (I presume all field biologists walk around with a hand lens). To determine the pathway for a particular leaf, pick a leaf and pull it apart to create a visible cross section. With a 10x hand lens, look at the cross section. If the cross section is green throughout, then it is a C3 leaf (as shown above). If instead you see darker green spots in a background of pale green, then it is a C4 leaf (as shown above). A more sophisticated way is to measure the leaf carbon isotope ratio back in the laboratory.
Picture
Grasses on campus lawns are called sod-forming grasses or turf grasses. They grow horizontally, sending out stolons at or below the soil surface and forming an extensive network of below ground roots. That below ground mass is referred to as sod. Native sod grasses include Bouteloua curtipendula (side-oats grama) and Distichlis spicata (salt grass). In contrast, bunch grasses do not have well-developed stolons and therefore appear as tufted grasses. Most of our native grasses are bunch grasses, including  Oryzopsis hymenoides (indian ricegrass) and Stipa comata (needle-and-thread grass)
Jim Ehleringer, University of Utah