Card Set Information

2010-03-22 23:34:58
ecology chapter 9

ecology chapter 9--Properties of Populations
Show Answers:

  1. Population
    a group of individuals of the same species that inhibit a given area
  2. characteristics of a population include:
    • - density
    • - proportion of individuals of various ages and stages
    • - spacing of individuals
    • - birth, death, and movement of individuals
  3. and individual organism has a unitary nature, meaning-->
    form, development, growth, and longevity (the zygote grows into a genetically unique organism)
  4. in modular organisms-->
    the zygote develops into a unit of construction that then produces futher, similar modules (common in plants)
  5. genet
    genetic individual arising from a zygote
  6. ramets
    • modules produced asexually by the genet
    • -ramets may be physically linked to the parent or separate
    • -ramets are clones or exact copies of the parent genet (corals or sponges)
  7. distribution
    • describes the population's spatial location
    • - influenced by the occurrence of suitable environmental conditions
  8. geographic range
    the area of a population that encompasses all individuals of a species
  9. the distribution of a population defines its spatial location:
    • individuals are not distributed evenly throughout the geographic range of a population
    • individuals can only occupy areas that can meet their requirements
  10. local or subpopulations
    • due to environmental heterogeneity, populations are divided into these
    • a metapopulation is a collection of local subpopulations
  11. abundance
    is the number of individuals in the population and defines its size
  12. population density
    the number of individuals per unit area or per unit volume
  13. population distribution pattern--random
    an individual's position is independent of other
  14. population distribution pattern--uniform
    results from negative interaction among individuals
  15. population distribution pattern--clumped
    results from patchy resources, social groupings, ramet dynamics
  16. population size formula
    population size=density x area
  17. sampling methods for plants and sessile animals
    • - counting the organism in a subsample (quadrats)
    • - abundance estimates may be skewed by a clumped spatial distribution
  18. capture-recapture or mark-recapture methods
    • based on trapping, marking, and releasing a known number of marked animals (M) into the population (N)
    • sometime later, the same population of sampled and the ratio of marked (R) to sampled (n) individuals in the second sample represents the ratio for the entrire population
    • N/M = n/R
    • Lincoln Index or Petersen index of relative population size
  19. indices of abundance
    counts of individuals based on vocalizations, scat, tracks, or other signs
  20. age structure
    • proportion of individuals in different age classes
    • determined by aging its members
  21. life history
    the length of time that an individual remains in each stage (short-lived vs. long lived organisms)
  22. dispersal
    the movement of individuals in space; directly influences their local density
  23. emigration
    when an individual moves OUT of a subpopulation
  24. immigration
    when an individual moves INTO a subpopulation
  25. passive dispersal
    • gravity, wind, water, animals
    • disperal distance depends on the agents of dispersal
  26. active dispersal
    • mobile animals
    • often the dispersing individals are seeking vacant habitat to occupy
  27. migration
    • a round trip movement made by an animal
    • can be daily, seasonal, short or long range
  28. range expansion
    • can be associated with temporal changes in environmental conditions
    • (ex. shift in tree population--retreating glaciers--more room for tree expansion)
  29. range expansion
    can result for populations that have been introduced to a region where they did not previously exist