Lesson 5.3 - Population Factors

Density-Independent Factors

Factors that affect populations regardless of population density; often abiotic, such as weather events, floods, and pollution.

Density-Dependent Factors

Factors that have a greater effect when the population density is high; often biotic factors.

Intraspecific Competition

Competition among individuals of the same species for resources such as food and shelter.

Interspecific Competition

Competition between different species for the same resources.

Competitive Exclusion Principle

The principle that states that two species competing for the same resources cannot coexist if other ecological factors are constant.

Resource Partitioning

The process where species living in the same area use different resources to reduce competition.

Defense Mechanisms

Adaptations used by organisms to protect against predators, such as camouflage or toxicity.

Mimicry

When one species evolves to resemble another species for protection or other advantages.

Parasitism

A symbiotic relationship where one organism is harmed while the other benefits.

Mutualism

A symbiotic relationship where both organisms involved benefit.

Commensalism

A symbiotic relationship where one organism benefits and the other is unaffected.

Keystone Species

A species that plays a critical role in maintaining the structure of an ecological community.

Limiting Factors

Environmental conditions that restrict the growth, abundance, or distribution of organisms.

Biotic Factors

Living components of an ecosystem, such as plants, animals, and microorganisms.

Abiotic Factors

Non-living physical and chemical elements of the environment, such as sunlight, temperature, and soil.

Population Dynamics

The study of how and why populations change over time, including factors like birth rates, death rates, immigration, and emigration.

Ecological Succession

The process by which ecosystems change and develop over time, often following a disturbance.