Ecology Chapter 8

  1. Concept 8.1: Populations are dynamic entities that vary
    in size over time and space.
  2. Concept 8.2: The distributions and abundances of organisms are limited by
    habitat suitability, historical factors, and dispersal.
  3. Concept 8.3: Many species have a -------------of populations across their geographic range.
    patchy distribution
  4. Concept 8.4: The dispersion of individuals within a population depends on the (3 things)
    location of essential resources, dispersal, and behavioral interactions.
  5. Distribution:
    Geographic area over which individuals of a species occur.
  6. Abundance:
    The number of individuals in a specific area
  7. Ecologists often wish to understand what factors determine the -------------and ------------- of species.
    distribution and abundance
  8. Biomass
    The total weight of individuals in a specific area
  9. Density
    Number of individuals per unit area (land) or volume (density)
  10. Mark recapture experiments
  11. M/N=m/n what do letters stand for?
    • M = number of marked individuals released
    • N = actual size of population
    • m = number of marked individuals captured the 2nd time
    • n = the total number of individuals 2nd time
  12. Distribution – can have 2 definitions 1
    • 1The geographic range of an organism
    • (Determined on the MACRO scale usually by abiotic factors)
  13. Distribution – can have 2 definitions 2
    2The spatial arrangement of individuals in a local population (Determined on the MICRO scale, usually by both abiotic and biotic factors)
  14. Abundance can be reported as -------- or -----------
    population size (# individuals), or density (# individuals per unit area).
  15. Individuals can be defined as
    products of a single fertilization: The aspen grove would be one individual, a genet.
  16. Members of a genet may be independent physiologically, so members of a genet are called --------
  17. Abiotic features of the environment include (5)
    moisture, temperature, pH, sunlight, nutrients, etc.
  18. disturbance-
    events that kill or damage some individuals, creating opportunities for other individuals to grow and reproduce.
  19. Individuals are uniformly spaced through the environment Cause? (2)
    • 1Antagonistic interactions between individuals
    • 2Local depletion of resources
  20. An individual has an equal probability of occurring anywhere in an area Cause?(2)
    • 1Neutral interactions between individuals and the environment
    • 2Neutral interactions between individuals
  21. Individuals live in areas of high local abundance separated by areas of low abundance Cause? (2)
    • 1Attraction between individuals
    • 2Attraction of individuals to a common resource
  22. Dispersion is the
    spatial arrangement of individuals within a population:
  23. Dispersion types (3)
    • 1Regular (uniform)—individuals are evenly spaced.
    • 2Random—individuals scattered randomly.
    • 3Clumped (aggregated)—the most common pattern
  24. The ecological niche:
    The physical and biological conditions that a species needs to grow, survive, and reproduce.
  25. A niche model is a
    predictive tool that models the environmental conditions occupied by a species based on the conditions at localities it is known to occupy.
Card Set
Ecology Chapter 8
Ecology Chapter 8