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64 Cards in this Set

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includes all the organisms in a given area as well as the abiotic factors with which they interact
trophic structure
the different feeding relationships in an ecosystem that determine the route of energy flow and the pattern of chemical cycling
trophic level
the division of species in an ecosystem on the basis of their main nutritional source. autotrophs, or primary producers, support all others.
primary producers
autotophs which collectively make up the trophic level of an ecosystem that ultimately supports all other organisms, usually photosynthetic
primary consumers
herbivores in the trophic level of an ecosystem that eat plant or algae
secondary comsumers
carnivores in the trophic level of an ecosystem that eat herbivores
tertiary consumers
a high-level consumer, which is usually the top predator in an ecosystem and/or food chain.
organisms that absorb nutrients from nonliving organic material and convert them into inorganic forms
food chain
the pahtway along which food is transferred from trophic level to trophic level
food web
the elaborate, interconnected feeding relationships in an ecosystem
primary productivity
the rate at which light energy or inorganic chemical energy is converted to the chemical energy of organic compounds by autotophs in an ecosystem
gross primary productivity
the total primary productivity in an ecosystem
net primary productivity
GPP minus the energy used by the producers for cellular respiration; represents the storage of chemical energy in an ecosystem available to consumers
the dry weight of organic matter comprising a group of organisms in a particular habitat
standing crop biomass
total biomasss of plants standing at an instant
limiting nutrient
The nutrient in short supply relative to the others that will be exhausted first and will thus limit cellular growth
secondary productivity
the rate at which all the heterotrophs in an ecosystem incorporate organic material into new biomass, which can be equated to chemical energy
ecological efficiency
the ratio of net productivity at one trophic level to net productivity at the next lower level
energy pyramid
"pyramid of productivity" where the size of each block is proportional to the productivity of each trophic level
biogoechemical cycle
the various nutrient circuits, which involve both biotic and abiotic components of ecosystems
aerobic bacteria's use of ammonium to oxidize ammonia to nitrite(NO2) and then to nitrate(NO3)
the decomposition of organic nitrogen back to ammonia, recycling large amounts of nitrogen
the process of reducing nitrate(NO3) and nitrite(NO2) into unaecessable gaseous nitrogen
eutrophic lake
a highly productive lake, having a high rate of biological productivity supported by a high rate of nutrient cycling
biological magnification
a trophic process in which retained substances become more concentrated with each link in the food chain
the variation of taxonomic life forms within a given ecosystem, biome or for the entire Earth
all of the organisms that inhabit a particular area; an assemblage of populations of different species living close enough together for potential interaction
individualistic hypothesis
a chance assemblage of organisms living in a given area because they share similar environmental requirements
interactive hypothesis
each community is a group of closely linked species having mandatory interactions that cause communities to function as integrated units
a change in one species acts as a new selective pressure on a second species which affects selection of first
an organism that feeds on another organism
an organism that is eaten by a predator
secondary compounds
organic compounds that are not directly involved in normal growth, reproduction, or development
cryptic coloration
defense mechanism that is a camouflage for a creature against its background
aposematic coloration
a family of antipredator adaptations where a warning signal is associated with the unprofitability of a prey item to potential predators
a situation where a mimic has evolved to share similar outward characteristics with another organism
Batesian mimicry
where a palatable species evolves to look like an unpalatable one, providing a benefit for the palatable species
Mullerian mimicry
where two unpalatable species look the same, providing a benefit for both species
(+,-) relationship where a parasite's growth and stability are maintained by a host, harms the host
brood parasite
the use of the same or different species of hosts to raise an organism's young
interspecific competition
(-,-) relationship where individuals of different species compete for the same resources in an ecosystem
competitive exclusion principle
two species competing for the same resource cannot exist in one area because one will use the resources more effieciently
ecological niche
the sum total of an organism's use of biotic and abiotic resources in its environment
fundamental niche
the resources a population is theoretically capable of using
realized niche
the resources a population actually uses
resource partitioning
sympatric species consume slightly different foods
a form of interspecific interation in which a host species and a symbiot maintain a close association
(+,0) interaction where a symbiot benefits and a host is unaffected
(+,+) relationship where both organisms benefit and a change in either species is likely to affect the survival and reproduction of the other; requires the evoltion of adaptations in both species
relative abundance
a measure of the proportion of a species in the community
species diversity
the number AND relative abundance of species in a community
species richness
the number of species in a community
secondary succession
a process started by an event that reduces an already established ecosystem to a smaller population of species
the tendency of a community to reach and maintain an equilibrium in responce to disturbances
community resilience
the ability of a community to persist in the face of a disturbance
exotic species
a species that is not native to an area; often takes over native species' habitats, outcompetes them
keystone predator
may exert a regulating effect on a community, reduce density of strong competitor, and make "room" for a second population
ecological succession
transition in species composition in a community over time
primary succession
begins in areas barren of life with a low biodiversity, low nutrients in soil, and harsh conditions
climax community
the most stable community with the most energy, most biodiversity, most nutrient rich soil, and environmental conditions are such that one set of species can continue
fugitive species
a species adapted to colonize newly disturbed habitats
describes species interactions that benefit at least one of the participants and cause harm to neither
intermediate disturbance hypothesis
moderate levels of predictable disturbances increase biodiversity and high levels of disturbances lower biodiversity
the study of the past and present distribution of species and communities