5/6/24 - Lecture 20: Competitive Interactions Flashcards
How are both species affected by competition?
Both individuals harmed by the interaction
How are both species affected by ammensalism?
One individual harmed, the other unaffected
How are both species affected by predator/prey interactions?
One individual benefits and the other is harmed
How are both species affected by mutualism?
Both individuals benefit from the interaction
How are both species affected by commensalism?
One individual benefits, the other is unaffected by the interaction
Intraspecific competition
Competition between individuals of the same species
Interspecific competition
Competition between individuals of two or more different species
Competitive exclusion principle
Two species that use the same resources in the same way cannot coexist
The R* rule
For two species competing for a single limiting resource, the species that can suppress the resource to the lower equilibrium level (R*) will competitively exclude the other species
Niche utilization curve
The frequency at which a species uses a range of resource types or the performance of a species for a range of environmental conditions
Niche overlap
Corresponds to the area of overlap between resource use curves for two competing species. Coexistence is determined by the degree of niche overlap
Negative frequency dependence
Selects for rare phenotypes in a population. The rarer phenotype is favored, but is inhibited the more common it becomes
Character displacement
Differences between similar species are greater in places where they co-occur and minimal in places where their distributions do not overlap
Bell curves separated when together because of directional selection to minimize competition
Self thinning in plants
1 = NL^2 = N[M^(1/3)]^2 = NM^(2/3)
or M = N^(-3/2)
1 is some area or space. The equation assumes all space is taken up. Substitute M in for L
N: number of plants
L: length of plants (^2 for area)
M = L^3, L = M^(1/3)
