Biology ch 54

  1. community
    a group of populations of different species living close enough to interact
  2. interspecific interactions
    • may be positive for one species (+), negative (-), or neutral (0)
    • include competition, predation, and symbioses
  3. interspecific competitions
    • occur when resources are short in supply
    • -/- interaction between the species
  4. competitive exclusion principle
    when 2 species are vying for a resource, eventually the one with the slight reproductive advantage will eliminate the other
  5. ecological niche
    the sum total of biotic and abiotic resources that the species uses in its environment
  6. fundamental niche
    the niche potentially occupied by a species
  7. realized niche
    the portio =n of the fundamental niche the species actually occupies
  8. predation
    a +/- interaction between 2 species in which one species eats the other species
  9. cryptic coloration
    an organism is camouflaged by its coloring
  10. Aposematic (warning) coloration
    a poisonous animal is brightly colored as a warning to other animals
  11. batesian mimcry
    refers to a situation in which a harmless species has evolved to mimic the coloration of an unpalatable/harmful species.
  12. Mullerian mimicry
    2 bad-tasting species resemble each other so that predators learn to avoid them equally
  13. herbivory
    a +/- interaction in which an herbivor eats part of a plant or alga.
  14. symbiosis
    occurs when individuas of 2 or more species live in direct contact with one another
  15. parasitism
    • a +/- symbiotic interaction in which the parasite derives its nourishment from its host
    • may have a significant effect on the survivalm reproduction, and density of their host population
  16. mutualism
    • an interspecific interaction that benefits both species (+/+)
    • (Both pollinators and flowering plants benefit from their relationship)
  17. commensalism
    • benefits one species, but neither harms nor helps the other (+/0)
    • (a fern growing in the shade of another plant)
  18. species diversity
    • measures the number of different species in a community (species richness) and the relative abundance of each speices
    • (a community with an even species abundance is more diverse than one in which one or two species are abundant and the remainder are rare)
  19. trophic structure
    the feeding relationships among organisms
  20. trophic leves
    the links in the trophic structure of a community
  21. food chain
    the transfer of food energy from plants through herbivores through carnivores through decomposers (from one trophic level to another)
  22. food web
    consist of 2 or more food chains linked together
  23. dominant species
    have the highest biomass (most abundant)
  24. biomass
    the sum weight of all the members of a population
  25. keystone species
    exert control on community by their important ecological niches
  26. disturbance
    storm, fire, flood, drought, or human activity changes a community by removing organisms or changing resource availibility. Not always bad
  27. intermediate disturbance hypothesis
    states that moderate levels of disturbance create conditions that foster greater species diversity than low or high levels of disturbance
  28. ecological succession
    transitions in species composition in a certain area of ecological time
  29. primary succession
    plants and animals gradually invade a region that was virtually lifeless where soil has not yet formed
  30. secondary succession
    an exisiting community has been cleared by a disturbance that leaves the soil intact
  31. how is the latitude of the community important in community diversity?
    plant and animal life is generally more abundant and diverse in the tropics, becoming less so moving toward the poles
  32. how is the area of the community important in community diversity?
    if all other factors are held equal, the larger geographic area of a community is, the more species it has
  33. why are islands good for studying biologial factors?
    • because of their isolation and sixe
    • also, land such as national parks surrounded by development work
  34. island biogeography is influence by
    • 1. rates of immigration and extincion are influenced primarily by the size of the island and the distance from mainland. The greater the sizes of the island, the higher the immigration rates and the lower the rates of extinction
    • 2. As the distance from the mainand increases, the rate of immigration falls, and the rates of extinction increase
  35. resource partitioning
    the differentitation of niches that enables similar species to coexist in a commuity
  36. character displacement
    the tendency for characteristics to diverge more in sympatric populations of 2 species than in allopatric populations of the same 2 species
  37. allopatric speciation
    the formation of new species in populations that are geographically isolated from one another
  38. sympatric speciation
    the formation of new species in populations that live in the same geographic area
  39. endoparasite
    parasites that live within the body of their host (tapeworms)
  40. ectoparasites
    parasites that feed on the external surface of a host (ticks, lice)
  41. species richness
    the number of different species in an area
  42. relative abundance
    the proportion each species represents of all individuals in a community
  43. energetic hypothesis
    suggests that the length of a food chain is limited by the inefficiency of energy transfer along the chain
Card Set
Biology ch 54
Chapter 54: Community Ecology