Term
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Definition
| An assemblage of populations of various species living close enough for potential interaction. |
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Term
| Interspecific Interactions |
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Definition
| Interactions with other species in the community. |
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Term
| Interspecific Competition |
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Definition
| Occurs when species compete for a particular resource that is in short supply. (-/-) |
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Definition
| Competition that leads to the local elimination of one or two competing species. |
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Definition
| The sum total of a species' use of the biotic and abiotic resources in its environment. |
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Definition
| The niche potentially occupied by a species. |
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Definition
| The niche a species occupies in a particular environment. |
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Definition
| Differentiation of niches that enables similar species to coexist in a community; Ex) one species hunt during the day, the other at night. |
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Definition
| The tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species; ex) variations in beak size between different populations of two species of Galapagos finches. |
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Definition
| Geographically separate populations that are generally morphologically similar and use similar resources. |
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Definition
| Geographically overlapping populations that generally show differences in body structures and in the resources they use. |
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Term
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Definition
| Refers to interaction between species in which one species, the predator, kills and consumes the other, the prey. (+/-) |
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Term
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Definition
| Camouflage; makes prey difficult to spot. |
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Term
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Definition
| The bright coloration of animals with effective physical or chemical defenses that acts as a warning to predators. |
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Term
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Definition
| A palatable or harmless species mimics an unpalatable or harmful model. |
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Term
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Definition
| Two or more unpalatable species resemble each other. |
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Term
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Definition
| Refers to an interaction in which an herbivore eats parts of a plant or alga. (+/-) |
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Term
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Definition
| A symbiotic interaction in which one organism, the parasite, derives it nourishment from another organism, its host, which is harmed in the process. (+/-) |
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Term
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Definition
| An organism that benefits by living in or on another organism at the expense of the host. |
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Term
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Definition
| The larger participant in a symbiotic relationship, serving as home and feeding ground to the symbiont. |
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Term
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Definition
| Parasites that live within the body of their host. |
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Term
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Definition
| Parasites that feed on the external surface of a host. |
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Term
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Definition
| Parasites (usually insects) that lay eggs on or in living hosts. |
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Term
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Definition
| Disease-causing agents similar to parasites. (+/-) |
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Term
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Definition
| An interspecific interaction that benefits both species (+/+); aka mutualistic symbiosis. |
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Term
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Definition
| An interspecific interaction that benefits one of the species but neither harms nor helps the other. (+/0) |
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Term
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Definition
| Reciprocal evolutionary adaptations of two interacting species. |
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Term
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Definition
| The variety of different kinds of organisms that make up a community. |
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Term
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Definition
| The total number of different species in a community. |
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Term
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Definition
| The proportion each species represents of the total individuals in a community. |
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Term
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Definition
| The feeding relationships between organisms. |
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Term
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Definition
| The transfer of food energy up the trophic levels from its source in plants and other photosynthetic organisms through herbivores to carnivores and eventually to decomposers. |
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Term
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Definition
| The elaborate, interconnected feeding relationships in an ecosystem. |
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Term
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Definition
| A hypothesis that suggests the length of a food chain is limited by the inefficiency of energy transfer along the chain. |
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Term
| Dynamic Stability Hypothesis |
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Definition
| A hypothesis that proposes that long food chains are less stable than short chain due to population fluctuations. |
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Term
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Definition
| Species in a community that are the most abundant or that collectively have the highest biomass. |
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Term
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Definition
| The total mass of all individuals in a population. |
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Term
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Definition
| Species, generally introduced by humans, that take hold outside their native range. |
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Term
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Definition
| Species that exert strong control on a community structure not by numerical might but by their pivotal ecological roles (niches). |
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Term
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Definition
| Foundation species that have positive effects on the survival and reproduction of some of the other species in the community by altering the structure or dynamics of the environment. |
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Term
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Definition
| A model of community organization in which mineral nutrients control community organization because nutrients control plant numbers, which in turn control herbivor numbers, which in turn control predator numbers. |
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Term
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Definition
| A model of community organization in which predation controls community organization because predators control herbivores, which in turn control plants, which in turn control nutrient levles; aka trophic cascade model. |
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Definition
| A technique for restoring eutrophic lakes that reduces populations of algae by manipulating the higher-level consumers in the community rather than by changing nutrient levels or adding chemical treatments. |
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Term
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Definition
| The model of communities that emphasize that they are not stable in time but constantly changing after being buffeted by disturbances. |
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Term
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Definition
| An event that changes a community, removes organisms from it, and alters resource availability. |
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Term
| Intermediate Disturbance Hypothesis |
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Definition
| A hypothesis, supported by a broad range of studies of terrestrial and aquatic communities, suggests that moderate levels of disturbance can create conditions that foster greater species diversity than low or high levels of disturbances. |
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Term
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Definition
| A process by which a disturbed area is colonized by a variety of species, which are gradually replaced by other species, which are in turn replaced by still other species. |
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Term
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Definition
| A type of ecological succession that occurs in a virtually lifeless area, where there were originally no organisms and where soil has not yet formed. |
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Term
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Definition
| A type of ecological succession that occurs when an existing community has been cleared by some disturbance that leaves the soil intact. |
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Term
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Definition
| The evaporation of water from soil plus the transpiration of water from plants. |
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Term
| Actual Evapotranspiration |
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Definition
| Determined by the amount of solar radiation, temperature and water availability; much higher in hot areas with abundant rainfall. |
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Term
| Potential Evapotranspiration |
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Definition
| A measure of energy availability but not water availability; determined by the amount of solar radiation and temperature; highest in regions of high solar radiation and temperature. |
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Term
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Definition
| One of the first patterns of biodiversity to be recognized; illustrates that the larger the geographic area of a community, the greater the number of species. |
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Term
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Definition
| Describes a community as an assemblage of closely linked species, locked into association by mandatory biotic interactions that cause the community to function as an integrated unit - in effect, as a superorganism. |
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Term
| Individualistic Hypothesis |
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Definition
| Depicts a plant community as a chance assemblage of species found in the same area simply because they happen to have similar abiotic requirements. |
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Term
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Definition
| Suggests that most of the species in a community are associated tightly with particular other species in a web of life; thus, reducing or increasing the abundance of one species in a community affects many other species. |
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Term
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Definition
| Most of the species in a community are not tightly associated with each other and the web of life is very looze; an increase or decrease in one species in a community has little effect on other species, which operate independently. |
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