ch19

Density Dependent Factors

• Definition: Factors that affect the population size in relation to its density. The impact of these factors increases as the population density increases.

  • Examples:

  • Food availability: Limited food supply becomes more impactful as population density rises, leading to competition.

  • Disease: Spread of diseases is often more rampant in dense populations, as individuals are closer and more likely to transmit pathogens.

  • Predation: Predators may be more successful in hunting when prey populations are dense.

  • Waste accumulation: In high-density populations, waste products can accumulate and affect health and reproduction rates.

Density Independent Factors

• Definition: Factors that affect population size regardless of its density. Their impact is not influenced by how many individuals are present in the area.

  • Examples:

  • Natural disasters: Events like hurricanes, floods, and wildfires can reduce populations regardless of density.

  • Climate Change: Changes in climate can lead to habitat loss and species extinction, affecting all individuals equally.

  • Pollution: The introduction of toxins affects populations regardless of density by impacting health and reproductive success.

  • Human Activities: Urbanization and deforestation can lead to habitat destruction affecting species independent of their population size.