BIOL 355: Ecology - Competition, Predation, & Herbivory

Exploitative competition

competition in which individuals consume or acquire a resource and thus deprive others of using it (indirect competition)

Interference competition

when individuals prevent access to a resource through aggressive or exclusionary methods (direct competition)

Allelopathy

a type of interference competition that occurs when organisms use chemicals to harm their competitors

Apparent competition

when two species have a negative effect on each other through an enemy—including a predator, parasite, or herbivore

Leibig’s law of the minimum

law stating that a population increases until the supply of the most limiting resource prevents it from increasing further

Competitive exclusion principle

two species that are limited by the same resources cannot coexist indefinitely in the same community

Logistic growth model with competition equation

see pic

Zero population growth isocline

population sizes at which a population experiences zero growth

If a population (species 2) is below the isocline, is it increasing or decreasing?

increasing

If the population (species 2) is above the isocline, is it increasing or decreasing?

decreasing

If a population (species 1) is to the left of the isocline, is it increasing or decreasing?

increasing

If a population (species 1) is to the right of the isocline, is it increasing or decreasing?

decreasing

Mesopredator

relatively small carnivores that consume herbivores

Top predators

predators that typically consume both herbivores and predators (e.g., mountain lions, wolves, sharks)

Crypsis

camouflage that either allows an individual to match its environment or breaks up the outline of an individual to blend in better with the background

Warning coloration (aposematism)

a strategy where distastefulness (or being “dangerous”) evolves in association with very conspicuous colors and patterns

Batesian mimicry

when palatable species evolve warning coloration that resembles unpalatable species (e.g., hover flies and hornet clearwings resemble the common wasp)

Müllerian mimicry

when several unpalatable species evolve a similar pattern of warning coloration (e.g., several species of poison dart frogs have evolved similar warning coloration)