Community Ecology Flashcards
competition that occurs between individuals of the same species
Intraspecific
competition that occurs between individuals of different species
Interspecific
organisms compete indirectly through the consumption of a limited resource with each obtaining as much as it can
Exploitation Competition
individuals interact directly with one another by physical force or intimidation
Interference Competition
when knapwood secretes into the surrounding soil root chemicals (allelochemicals) that kill the roots of native grass species
Allelopathy
unique set of habitat resources a species requires as well as its effect on an ecological system
Niche
two species with exactly the same requirements cannot live together in the same place and use the same resources
Competitive Exclusion Principle
differentiation of niches, in both space and time, that enables similar species to coexist in a community
Resource Partitioning
occurring in the same geographic area
Sympatric
occurring in different geographic areas
Allopatric
tendency for two species to diverge in morphology and thus resource use because of competition
Character Displacement
typically nonlethal predation on plants
Herbivory
death of prey
Predation
typically nonlethal; adult parasites usually live on and produce for long periods in or on the living host
Parasitism
warning colorations
Aposematic Defense
the blending of an organism with the background of its habitat and is a common method of avoiding detection by predators
Camouflage
the resemblance of a species to another species
Mimicry
two or more toxic species converge to look the same, thus reinforcing the basic distasteful design
Mullerian Mimicry
mimicry of an unpalatable species by a palatable one
Batesian Mimicry
compounds that are not part of the primary metabolic pathway; chemicals that are bitter tasting or toxic
Secondary Metabolites
the ability of plants to prevent herbivory via either chemical or mechanical defenses
Host Plant Resistance
an organism that lives in, or, or with another organism, called the host, in order to obtain nutrients, grow, or multiply, often directly or indirectly harming the host
Parasite
lack chlorophyll and are totally dependent on host plants for their water and nutrients
Holoparasites
able to carry out photosynthesis, but depend on their hosts for water and mineral nutrients
Hemiparasites
infect one species or just a few closely related species
Monophagous
can infect many different host species
Polyphagous
multiply within their hosts
Microparasites
live in the host but release infective juvenile stages outside of the host’s body
Macroparasites
live outside of the host’s body
Ectoparasites
live inside of the host’s body
Endoparasites
both species receive a benefit in the form of resource transfer of energy and nutrient
Resource-based Mutualisms
one species receive food or shelter in return for defending another species
Defensive Mutualism
interactions in which species receive food in return for transporting the pollen or seeds of its partner
Dispersive Mutualism
when species cannot live without the other
Obligatory Mutualism
interaction is beneficial but not essential to the survival and reproduction of either species
Facultative Mutualism
interaction between species in which one benefits and the other is neither helped or harmed
Commensalism
one organism uses a second organism for transportation
Phoresy
factors that influence the number of different species in a community
Species Richness
proposes that temperate regions have fewer species-rich communities than tropical ones because they are younger
Species-Time Hypothesis
the observation that the number of species tends to increase with increasing area
Species-Area Effect
proposes that greater production by plants results in greater overall species richness
Species-Productive Hypothesis
the rate at which water moves into the atmosphere through the processes of evaporation from the soil and other surfaces and transpiration by plants, which are influenced by the amount of solar energy
Evapotranspiration rate
frequency of occurrence
Relative Abundance
a measure of the diversity of an ecological community that incorporates both the number of species and their relative abundance
Species Diversity
converts values from species diversity indices into equivalent numbers of species.
Effective Number of Species
outbreaks of pests are often found on cultivated land or land disturbed by humans, both of which are species-poor communities with few naturally occurring species
Diversity-Stability Hypothesis
describes the gradual and continuous change in species composition of a community following a disturbance
Succession
refers to succession on a newly exposed site that has no biological legacy in terms of plants, animals, or microbes, such as bare ground caused by a volcanic eruption or the sediment created by the retreat of glaciers
Primary Succession
succession on a site that has previously supported life but has undergone a disturbance such as a fire, tornado, hurricane, or flood
Secondary Succession
succession as proceeding through several stages to a distinct end point
Climax Community
each colonizing species makes the local environment a little different, such as a little shadier or a little richer in soil nitrogen, so that it becomes more suitable for other species, which then invade and outcompete the earlier residents
Facilitation
early colonists prevent colonization by other species
Inhibition
any species can start the succession, but the eventual climax community is reached in a somewhat orderly fashion
Tolerance
the number of species on an island tends toward an equilibrium number that is determined by the balance between two factors: immigration rates and extinction rates
Equilibrium Model of Island Biogeography
suggests that species-rich communities are more stable than those with fewer species
Diversity-Stability Hypothesis
ecosystem function increases rapidly at fairly low levels of species richness, but then levels off because most additional species are functionally redundant
Redundancy Hypothesis
proposes that ecosystem function rises dramatically as species richness approaches its natural level
Keystone Hypothesis
suggests that although ecosystem function can change as the number of species increases or decreases, the amount and direction of change are unpredictable
Idiosyncratic Hypothesis
