Chapter 54

Created by

Sammie Tabliago

Cards (71)

A biological community is an assemblage of populations of various species living close enough for potential interaction
Some factors that influence the structure of a community are foundation species, interactions between species, and disturbances.
Interspecific interactions are interactions between individuals and members of other species
can have positive (+), negative (-), or neutral (0) effects
Interspecific competition (–/– interaction) occurs when species compete for a resource in short supply.
The competitive exclusion principle states that two species competing for the same limiting resources cannot coexist in the same place.
The total of a species’ use of biotic and abiotic resources is called the species’ ecological niche (the organism’s ecological role).
Ecologically similar species can coexist in a community if there are one or more significant differences in their niches.
Resource partitioning is differentiation of ecological niches, enabling similar species to coexist in a community.
Fundamental niche is the niche potentially occupied by that species.
Realized niche is the niche actually occupied by that species.
As a result of competition, a species’ fundamental niche may differ from its realized niche.
The common spiny mouse and the golden spiny mouse show temporal partitioning of their niches.
Both the common spiny mouse and the golden spiny mouse are normally nocturnal but when they coexist, the golden spiny mouse becomes diurnal.
Character displacement is a tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species.
Predation (+/– interaction) refers to an interaction in which one species, the predator, kills and eats the other, the prey.
Adaptations of predators include claws, teeth, fangs, stingers, and poison.
Adaptations of prey include:
behavioral defenses include hiding, fleeing, forming herds or schools, self-defense, and alarm calls
morphological and physiological defense adaptations, and cryptic coloration
An example of mechanical defense is a porcupine.
An example of chemical defense is a skunk.
An example of cryptic coloration is a canyon tree frog.
Aposematic coloration is a warning coloration.
An example of aposematic coloration is a poison dart frog.
Batesian mimicry is a palatable or harmless species mimics an unpalatable or harmful model
ex. hawkmoth larva and a green parrot snake
Müllerian mimicry is when two or more unpalatable species resemble each other.
ex. cuckoo bee and yellow jacket
Herbivory (+/– interaction) refers to an interaction in which an herbivore eats parts of a plant or algae.
Herbivory interactions has led to the evolution of plant mechanical and chemical defenses and adaptations by herbivores.
Adaptations can enhance survival as herbivore or plant.
Symbiosis is a relationship where two or more species live in direct and intimate contact with one another.
Examples of symbiosis include nitrogen-fixing bacteria and legumes, mycorrhizal fungi and plants.
In parasitism (+/– interaction), one organism, the parasite, derives nourishment from another organism, its host, which is harmed in the process.
Examples of parasitism are endoparasites and ectoparasites.
Mutualistic symbiosis, or mutualism (+/+ interaction), is an interspecific interaction that benefits both species.
A mutualism can be obligate or facultative.
Obligate is when where one species cannot survive without the other
ex. Corals with dinoflagellates
Facultative is where both species can survive alone.
Commensalism (+/0 interaction) is when one species benefits and the other is neither harmed nor helped.
Two fundamental features of community structure are species diversity and feeding relationships.
Species diversity of a community is the variety of organisms that make up the community.
Species richness is the number of different species in the community.
Relative abundance is the proportion each species represents of all individuals in the community.