Primary Productivity

  1. GPP (Gross Primary Productivity)
    the rate of fixation of carbon by photosynthesis per unit area per unit time (before carbon in lost to respiration of mortality)
  2. Net Primary Productivity
    The amount of organic matter produced that is left "after" the respiration of plant per area per time
  3. Net ecosystem productivity
    =GPP-autotrophic respiration- heterotrophic respiration

    =NPP- heterotrophic respiration

    The organic matter that has been produced and is left over at the end of the period (1 year) including that which may be exported.
  4. Changes in GPP/NPP over succession
    • primary succession: huge change has been made and the ecosystem needs to start over (Ex-mudslide)
    • secondary succession: most plants/animals wiped out, but some of the ecosystem still exists (ex- Fire)
  5. what magnitudes NPP in g/m2/yr are high or low
    in a growing forest, the NPP curve rises with the GPP curve until the GPP curve has stabilized. The NPP curve drops. (canopy has enclosed)
  6. Factors Controlling NPP in wetlands
    • 1) growing season, (related to latitude and temp)
    • 2) Salinity
    • 3) Soil nutrient availability
    • 4) Hydroperiod (affects several factors)
    • -Flowing water>sluggish water>Still water (less productive)
Card Set
Primary Productivity
Quiz 3