Lecture Notes: Carrying Capacity and Population Dynamics

Key Concepts

• Carrying Capacity:

  • Definition: The maximum number of individuals an environment can sustain.
  • Populations can exceed the carrying capacity temporarily, but not sustainably.
  • Related to the balance between resource use and resource renewal.

• Resource Dynamics:

  • Carrying capacity shifts with changes in resource availability.
  • Limiting factors: Elements that restrict resource supply and population growth.

Example: Deer Population and Carrying Capacity

• Initial Conditions:

  • Deer population has ample resources, primarily grass.
  • Population grows exponentially due to abundant resources.

• Population Overshoot:

  • Birth rate exceeds death rate, leading to exponential growth.
  • Population grows beyond the carrying capacity (overshooting).

• Consequences of Overshoot:

  • Grass resources thin due to overgrazing.
  • Increased food competition and starvation among deer.
  • Population crashes below original carrying capacity.

• New Carrying Capacity:

  • Damage to grass results in a reduced carrying capacity.
  • New carrying capacity reflects the reduced resource availability.

• Long-Term Recovery:

  • Grass can rejuvenate over time, potentially restoring original carrying capacity.
  • Deer population stabilizes around the new carrying capacity, avoiding further overshoot risks.

Conclusion

• Understanding carrying capacity is crucial for managing wildlife populations.
• Overshooting carrying capacity can lead to significant ecological damage and changes in population dynamics.
• Recovery of natural resources takes time, emphasizing the importance of sustainable population management.