ENV 100 ch 7

  1. "Gulf Dead Zone"
    • = a region of water so depleted of oxygen
    • that kills or drives away marine organisms
  2. Hypoxia
    low concentrations of dissolved oxygen water

    Caused by fertilizer, runoff, sewage
  3. System
    a network of relationships among parts elements or components that interact with and influence one another

    Exchange of energy, matter, or information

    Receives inputs of energy, matter, or information; processes these inputs; and produces outputs
  4. Feedback loop
    a system’s output serves as input to that same system

    A circular process
  5. Negative Feedback Loop
    output that results from a system moving in one direction acts as input that moves the system in the other direction.
  6. Positive feedback loop
    •instead of stabilizing a system, it drives it further toward one extreme or another

    •Examples: exponential growth in human population, spread of cancer, erosion
  7. Dynamic Equilibreum
    system processes move in opposing directions at equivalent rates, balancing their effects
  8. Homeostasis
    a system maintains constant or stable internal conditions
  9. Emergent Properties
    • system characteristics not evident in the components alone
    • “The whole is more than the sum of the parts”
  10. Lithosphere
    rock and sediment
  11. atmosphere
    the air
  12. Hydrosphere
    liquid, solid, or water
  13. Biosphere
    all the planet’s living organisms and the abiotic portions of the environment
  14. Gross Primary Production
    assimilation of energy by autotrophs
  15. Net Primary Production
    energy remaining after respiration, and is used to generate biomass
  16. Secondary Production
    biomass generated by heterotrophs
  17. Productivity
    rate at which ecosystems generate biomass
  18. High Net Productivity
    ecosystems whose plants rapidly convert solar energy to biomass
  19. Nutrients
    elements and compounds required for survival that are consume by organisms
  20. Macronutrients
    nutrients required in relative large amounts

    -Nitrogen, carbon, phosphorus
  21. Micronutrients
    nutrients needed in smaller amounts
  22. Ecotones
    transitional zones between two ecosystems in which elements of different ecosystems mix
  23. Landscape Ecology
    the study of landscape structure and how it affects the abundance, distribution, and interaction of organisms
  24. Metapopulation
    • a network of subpopulations
    • Most members stay within patches but may move among patches or mate with those of other patches
    • Individuals in small patches risk extinction
  25. Habitat Fragmentation
    breaking habitat into small, isolated patches due to human impact
  26. Pools
    where nutrients reside for varying amounts of time
  27. Flux
    movement of nutrients among pools, which change over time and are influenced by human activities
  28. Sources
    pools that release more nutrients than they accept
  29. Sinks
    accept more nutrients than they release
  30. Carbon Cycle
    describes the routes that carbon atoms take through the environment
  31. Phospherous Cycle
    describes the routes that phosphorus atoms take through the environment
  32. Nitrogen Cycle
    describes the routes that nitrogen atoms take through the environment
  33. Nitrogen Fixation
    Nitrogen gas is combined (fixed) with hydrogen by nitrogen-fixing bacteria to become ammonium
  34. Nitrification
    bacteria that convert ammonium ions first into nitrite ions then into nitrate ions
Card Set
ENV 100 ch 7
test 2