Environmental Biology

  1. Population
    Group of organisms of the same species occupying a given space at a particular time.
  2. Deme
    Local populations of interbreeding organisms.

  3. Primary: Population Parameters: Density
    • Increase: Immigration & Natality
    • Decrease: Mortality & Emigration
  4. Secondary Characterisics of a population
    • Age distribution
    • genetic composition and variability
    • Distribution
  5. Exponential population Growth Occurs when?
    A population has unlimited resources
  6. Logistic Population Growth
    Stabilizing Factors which maintain a population at an equilibrium level
    • Resources
    • Births=Deaths
  7. Density -independent population growth
    Act upon individuals without regard to population density:

    Drought, Severe winter, hurricane & fire
  8. J-type growth
    Population size exceeds the carrying capacity. ( bacteria & Humans)
  9. Annual rate of natural population Change
    (Birth rate - Death rate) / 1,000 persons
  10. Carrying Capacity for Humans
    • 50 billion people
    • -if the entire ecological capacity of earth was devoted to the maintenance of human populations
    • -We would have extremely dense human populations.
  11. World population growth trends
    • Increased proportion living in urban areas. (future 48-60% expected)
    • -Fast in LDC's
    • -Slow in MDC's

    Increase in the number of megacities (pop> 1million)

    Poverty moving from rural to urban problem.
  12. Population Growth Projections
    • Increase to 8 billion in 20 years
    • With a majority born in low and middle income nations.
Card Set
Environmental Biology