| A | B |
|---|
| aposematic coloration | bright coloration of animals with effective physical or chemical defenses that acts as a warning to predators |
| Batesian mimicry | a harmless species looks like a species that is poisonous or otherwise harmful to predators |
| biomanipulation | reduces populations of algae by manipulating the higher-level consumers in the community rather than by changing nutrient levels or adding chemical treatments |
| biomass | dry weight of organic matter comprising a group of organisms in a particular habitat |
| bottom-up model | mineral nutrients control plant numbers which in turn control herbivore numbers which in turn control predator numbers |
| character displacement | tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species |
| coevolution | mutual evolutionary influence between two different species interacting with each other and reciprocally influencing each other’s adaptations |
| commensalism | relationship in which the symbiont benefits but the host is neither helped nor harmed |
| community | all organisms that inhabit a particular area |
| competitive exclusion | species compete for the same limited resources one population will use the resources more efficiently and have a reproductive advantage |
| cryptic coloration | making potential prey difficult to spot against its background |
| disturbance | force that changes a biological community and usually removes organisms from it |
| dominant species | species in a community that have the highest abundance or highest biomass. These species exert a powerful control over the occurrence and |
| dynamic stability hypothesis | long food chains are less stable than short chains |
| ecological niche | sum total of a species’ use of the biotic and abiotic resources in its environment |
| ecological succession | Transition in the species composition of a biological community |
| ectoparasite | parasite that feeds on the external surface of a host |
| endoparasite | parasite that lives within a host |
| energetic hypothesis | concept that the length of a food chain is limited by the inefficiency of energy transfer along the chain |
| evapotranspiration | evaporation of water from soil plus the transpiration of water from plant |
| facilitator | species that has a positive effect on the survival and reproduction of other species in a community |
| food chain | pathway along which food is transferred from trophic level to trophic level |
| food web | elaborate interconnected feeding relationships in an ecosystem |
| herbivory | interaction in which an herbivore eats parts of a plant or alga |
| host | larger participant in a symbiotic relationship serving as home and feeding ground to the symbiont |
| individualistic hypothesis | a plant community is a chance assemblage of species found in the same area simply because they happen to have similar biotic requirements |
| integrated hypothesis | biotic interactions that cause the community to function as an integrated unit a sort of superorganism |
| intermediate disturbance hypothesis | moderate levels of disturbance can foster greater species diversity than low or high levels of disturbance |
| interspecies interaction | relationships between species of a community |
| interspecific competition | competition for resources between plants between animals or between decomposers when resources are in short supply |
| keystone species | species that is not necessarily abundant in a community yet exerts strong control on community structure by the nature of its ecological role or niche |
| Müllerian mimicry | mutual mimicry by two unpalatable species |
| mutualism | relationship in which both participants benefit |
| niche | role of species in ecosystem |
| non-equilibrium model | emphasizes that they are not stable in time but constantly changing after being buffeted by disturbances |
| parasite | organism that absorbs nutrients from the body fluids of living hosts |
| parasitoidism | insect lays eggs on or in a living host |
| pathogen | disease-causing agent |
| predation | interaction between species in which one species the predator eats the other the prey |
| primary succession | occurs in a virtually lifeless area where there were originally no organisms and where soil has not yet formed |
| redundancy model | most of the species in a community are not tightly coupled with one another |
| relative abundance | differences in the abundance of different species within a community |
| resource partitioning | division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species |
| rivet model | many or most of the species in a community are associated tightly with other species in a web of life |
| secondary succession | occurs where an existing community has been cleared by some disturbance that leaves the soil intact |
| species diversity | number and relative abundance of species in a biological community |
| species richness | number of species in a biological community |
| species-area curve | illustrates that the larger the geographic area of a community the greater the number of species |
| top-down model | predation controls community organization because predators control herbivores which in turn control plants which in turn control nutrient level |
| trophic structure | different feeding relationships in an ecosystem which determine the route of energy flow and the pattern of chemical cycling |
