Lecture 17 - Competition - Observations

Competition - chapter 13. Stouffer's RNR 2021

Density dependence

Slows growth rate and limits population size as N approaches K.

Competition

Use or defense of a resource that reduces availability for other individuals.

Intraspecific competition

Competition among individuals of the same species.

Interspecific competition

Competition among individuals of at least two species.

Interference competition

Competition involving direct antagonistic interactions, resulting in harm or reduced resource access. ex. male elk fighting for access to females

Resource competition

Intraspecific or interspecific competition for limited resources. ex. first one there gets the best spot making it unavailable of later individuals

Intraspecific competition in plants

Only a small number of large individuals can be supported.

Niche

Environmental factors influencing the growth, survival, and reproduction of a species.

Abiotic factors

Temperature, rainfall, dissolved oxygen, magnesium, etc.

Biotic factors

Prey, predators, parasites, etc.

Fundamental niche

Physical conditions under which a species can live without interactions with other species.

Realized niche

Actual conditions under which a species lives, reduced from the fundamental niche due to interactions with other species.

Dominant competitor

Gains resources to the exclusion of weaker competitors.

Competitive exclusion principle

Two species cannot coexist indefinitely if they require the same limiting resource.