Chapter 19 Ecology

  1. Carbon is the currency because
    it is stored by autotrophs and transferred to heterotrophs
  2. Gross primary production (GPP)—
    total amount of carbon fixed by autotrophs in an ecosystem.
  3. GPP depends on the influence of climate on photosynthetic rate and the leaf area index (LAI)—
    leaf area per unit of ground area.
  4. Net primary production (NPP)=      
     NPP = GPP – respiration
  5. The balance between GPP and respiration;
    plant biomass gained NPP is allocated among growth, reproduction, storage, and defense NPP allocated to leaves, stems, and roots depends on resource availability of light, nutrients, water, and carbon NPP allocated to storage compounds is insurance
  6. Important to estimate NPP because:
    Source  for energy traveling to upper trophic levels Variation provides information on ecosystem change Closely tied to global carbon cycle; carbon moving from atmosphere into ecosystems
  7. Estimating belowground plant biomass (roots) is more difficult:
    Roots turnover much more rapidlyRoots transfer carbon to mycorrhizal or bacterial symbiontsMore frequent correction factorsalgorithms that relate above to
  8. Destructive Sampling (impractical over large scale): to measure NPP
    • Harvesting aboveground plant biomass before and after the growing seasonScale estimates up to the ecosystem
    • Provides a destructive estimate of NPP
  9. Create a closed system and measure CO2 inside tent. The CO2 change is called
    Net Ecosystem Exchange (NEE)
  10. Both ----------and-------------- directly affect NPP.
    precipitation and temperature
  11. NPP increases with increasing precipitation to a point.....
    Declines at higher precipitation because cloud cover limits photosynthesis and rain leaches nutrients from soils.
  12. NPP increases with
    increasing temperature.
  13. NPP in the open ocean is derived from --------and limited by
    phytoplankton and is mostly limited by nitrogen
  14. Near the coast, ------------and-------------- contribute to NPP in more shallow areas.
    kelp forests and seagrass beds. Equatorial Pacific ocean, nitrogen can be detected in the water
Card Set
Chapter 19 Ecology
Chapter 19 Ecology