Density-independent

Definition

Density-independent factors affect population size regardless of the population's density. These factors are typically abiotic, such as weather events or natural disasters.

5 Must Know Facts For Your Next Test

1. Density-independent factors can cause sudden and drastic changes in population size.
2. Examples of density-independent factors include hurricanes, droughts, wildfires, and temperature extremes.
3. Unlike density-dependent factors, these do not intensify as the population increases.
4. Density-independent factors can impact both large and small populations equally.
5. Adaptation to density-independent factors can influence the evolution of species.

Review Questions

• What distinguishes density-independent factors from density-dependent factors?
• Give three examples of density-independent factors.
• How do density-independent factors affect small versus large populations?

Related terms

density-dependent factor: Factors that affect population size in relation to the population’s density, such as competition and predation

abiotic factor: Non-living chemical and physical components of the environment that affect living organisms and ecosystems

carrying capacity: The maximum number of individuals in a species that an environment can support indefinitely