Study Notes on Carrying Capacity

3.4 Carrying Capacity

  • Definition of Carrying Capacity (F)

    • The maximum number of individuals in a population that an ecosystem can support, determined by the availability of limiting resources.
    • Expressed mathematically as:
      F=extMaxPopulationF = ext{Max Population}

  • Limiting Resources

    • Factors that influence carrying capacity, including:
    • Food
    • Water
    • Habitat

  • Overshoot

    • Occurs when a population temporarily exceeds the carrying capacity (K) due to a sudden increase in resources.
    • Example:
    • Deer breed in the spring and all give birth at once, resulting in a sudden spike in population.

  • Consequences of Overshoot

    • Leads to resource depletion, such as:
    • Overgrazing in deer populations, which can lead to drastic ecological effects.

  • Die-off

    • A sharp decrease in population size that occurs when overshoot leads to severe resource depletion.
    • Example:
    • In situations where too many new fawns are feeding in the spring, resource availability may diminish.
    • Case Study:
    • St. Paul Island:
      • 25 deer were introduced in 1910.
      • Initial growth was gradual (between 10-30 individuals); however, it reached an exponential growth phase (30-37).
      • A sharp die-off occurred as food resources became severely depleted due to overshoot.

  • Real Population Dynamics

    • Populations do not always fluctuate around the carrying capacity; if resource depletion is severe enough, it can lead to total population collapse.
    • Emphasis on the importance of sustainable resource management to prevent these scenarios from occurring.