ch 4

  1. age structure
    • The relative proportions of young, middle aged, and older individuals in a population

  2. biotic potential
    • The maximum reporoductive capacity of a species, express as a rate

  3. carrying capacity
    • The maximum population of a species that a particular environment can support

  4. commensalism
    • A symbiotic association in which one speicies (the commensal) is benefited while the other (the host) is not affected.

  5. competition
    • A symbiotic association in which the growth or survival of one of the species populations is adversely affected in instances in which a common resource in in short supply.

  6. competitive exclusion principle
    • The principle that two or more resources limited species, having identical patterns of resource use, cannot coexist in a stable environment, one outcompeting and eventually eliminating the other

  7. density dependent
    • Process that are regulated by the number of individuals present in a given space. ex, those that etiher increase mortality or decrease natality as the number of individuals in the population increases

  8. density independent
    • Processes that are not regulated by the number of individuals present in a given space

  9. environmenal resistance
    • The totality of abiotic and biotic environmental forces that revent the biotic potential of a species from being realized.

  10. Gause's principle
    • See competititve exclusion principle

  11. generation time
    • The length of time between generations of a population

  12. growth rate

  13. intrinsic rate of natural increase
    • The biotic potential of a species measured under optimal conditions

  14. J shaped growth curve
    • The shape of a growth curve in which there is a rapid exponential growth up to the limits imposed by the environment, at which point the population undergoes a rapid die off.

  15. macroparasites

    Parasites that are typically large, have longer generation times than microparasites do, and have no direct reproduction within the host.

  16. mean life expectancy

    Teh age at which one half of an initial population is still alive, techinically, the medial life expectancy.

  17. microparasites
    • Parasites that are generally small, have short generation times, and have direct reproduction, usually at high rates, within the host

  18. mortality
    • Death rate, the number of deathss in a cohort in a given time frame.

  19. mutualism
    • A symbiotic relationship in which both species bewnefit and neither can survivie without the other

  20. natality
    • Birth rate, the number of births in a cohort in a given time frame

  21. net reprodutive rate
    • The number of female offspring that replace each female of the previous generation

  22. neutralism
    • A symbiotic association in which the speicies populations have no effect on each other.

  23. parasitism
    • A symbiotic association in which one organism, thypically small ( the parasite) live in or on another ( the host), from which it obtains food, shelter, or othe requirements.

  24. predation
    • A symbiotic association in which one organism, typically larger (the predatior), obtains energy by consuming, usually killing, another ( the prey)

  25. protocooperation
    • A symbiotic associaton in which both speicies benefit but the relationship is not obligatory

  26. reproductive potential
    • The capacity of an individual to produce offspring, expressed as a rate.

  27. sigmoud growth curve
    • See s-shaped growth curve

  28. s-shaped growth curve
    • The mopre or less smooth curvilinear shape representing the rate of growth of a population in which densit initially increases slowly, then rapidly, and subsequently declines to zero.

  29. survivorship curve
    • a graph representing the survival of individuals in a population from birth to the maximum age attained by any one member, usually plotted logarithmically

  30. symbiosis
    • a term describing the ineraction of two species that live togehter in close association
Card Set
ch 4
population ecology