Flashcards in Lecture 32-Community Ecology Deck (57):
A group of populations of different species living close enough to interact.
4 types of interspecific interactions:
Interspecific competition, predation, herbivory, and symbiosis
Refers to an interaction in which an organism eats part of a plant or alga.
Occurs when individuals of different species compete for a resource that limits their growth and survival.
Occurs when individuals of two or more species live in direct and intimate contact with one another.
Refers to an interaction between species in which one species, the predator, kills and eats the other, the prey.
Even a slight reproductive advantage will eventually lead to local elimination of the inferior competitor.
Principle of competitive exclusion
The sum of a species' use of biotic and abiotic resources in its environment.
__________ __________ leads to competitive exclusion.
Niche overlap leads to:
The differentiation of niches that enables similar species to coexist in a community.
Indirect evidence of earlier interspecific competition resolved by the evolution of niche differentiation.
"The ghost of competition past"
The tendency for characteristics to diverge more in sympatric than in allopatric populations of two species.
When populations are sympatric, it means they are:
In the same place
Sympatric populations of two closely related species would potentially compete for the same resources, resulting in:
The divergence in morphological features
Many organisms have evolved __________ __________ against predation.
Camouflage; defense against visual predators.
Resembling an object that is a specific feature of its environment.
Warning coloration displaying toxic, noxious, or potent chemical defense, specifically against vertebrate predators.
Aposematic coloration is used specifically against:
Eye spots mimicking vertebrate predators.
Moths use startle display to resemble the eyes of an:
Snakes use startle display to resemble:
Aposematic inedible model and an edible mimic.
The model and the mimic are both distasteful and aposematic and benefit from existence.
Plant defense adaptation against herbivores.
3 types of herbivory:
Mechanical defense, allelochemicals, and semiochemicals
Examples of mechanical defense:
Examples of allelochemicals:
Toxins (nicotine or caffeine), polymers (lignins and tannins)
One organism, the parasite, derives its nourishment from another organism, its host, which is harmed in the process.
Interspecific interaction that benefits both species.
Interaction between species that benefits one of the species, but neither harms or helps the other.
The number and relative abundance of species in a biological community.
The number of different species in the community.
The proportion each species represents of all individuals in the community.
The structure and dynamics of a community depend in the:
Feeding relationships between organisms
Different feeding relationships in an ecosystem, which determine the route of energy flow and the pattern of chemical cycling.
The transfer of food energy up the trophic levels from its source to carnivores, and to decomposers.
Interconnected feeding relationships in an ecosystem.
Typically, how long is each food chain within a food web?
Only a few links long
Generally, what limits the length of food chains?
The inefficiency of energy transfer along the chain
The most abundant, or have the highest biomass in a community.
An example of a dominant species:
Exert strong control on community structure by pivotal ecological roles or niches.
An example of a keystone species:
Dramatically alter their physical environments on a large scale.
2 examples of ecosystem engineers:
Beavers and humans
An event that changes a community by removing organisms from it or altering resource availability.
6 examples of a disturbance:
Storm, fire, flood, drought, overgrazing, and human activity
What do disturbances do?
They reduce the dominant species and shift resources
__________-__________ species have an opportunity.
The community response after disturbance.
A type of succession that occurs in an area where there were originally no organisms present and where soil has not yet formed.
Describe secondary succession.
A type of succession that occurs where an existing community has been cleared by some disturbance that leaves the soil or substrate intact.
The increase in species richness or biodiversity that occurs from the poles to the tropics.
All other factors being equal, the larger the area, the more species it has.