Chapter 15 and 20 ecology

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Chapter 15 and 20 ecology
2012-11-20 09:14:25
Chapter 15 20 ecology

Chapter 15 20 ecology
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  1. 1
  2. Shannon Index
    learn variables
  3. Species composition—
    the identity of species present in the community.Two communities could have identical species diversity values, but have completely different species.The identity of species is critical to understanding community structure.
  4. Trophic facilitation occurs when
    a consumer is indirectly facilitated by a positive interaction between its prey and another species.
  5. Dominant species (foundation species) can have a large effect on other species and species diversity by virtue of
    high abundance or biomass.Dominant species may also be dominant by virtue of being good competitors for space, nutrients, or light
  6. Keystone species
    Critical species in environment
  7. Some dominant species are ecosystem engineers—they ...
    create, modify, or maintain physical habitat for themselves and other species ie trees
  8. Context-dependent species interactions can
    change under different environmental conditions.

    Some keystone species play important roles in their communities in one context, but not in another.
  9. Each feeding category, or trophic level, is based on
    the number of feeding steps by which it is separated from autotrophs.
  10. Concept 20.1: Trophic levels describe the
    feeding positions of groups of organisms in ecosystems.
  11. Concept 20.2: The amount of energy transferred from one trophic level to the next depends on
    food quality and consumer abundance and physiology.
  12. Concept 20.3: Changes in the abundances of organisms at one trophic level can influence
    energy flow at multiple trophic levels.
  13. Concept 20.4: Food webs are conceptual models of the
    trophic interactions of organisms in an ecosystem.
  14. Much of the input of detritus into streams, lakes, and estuarine ecosystems is derived from terrestrial organic matter.These external energy inputs are called ---------------.Energy produced by autotrophs within the system is ----------------
    • allochthonous inputs
    • autochthonous energy.
  15. The second law of thermodynamics states that
    during any transfer of energy, some is lost due to the tendency toward an increase in disorder (entropy).Energy will decrease with each trophic level.
  16. trophic pyramid = -----------------------------------
    .rectangles =
    • -graphical representation of trophic relationships
    • -relative amounts of energy or biomass of each level.