E
Ebracteate
Having no bracts.
Ecdysis
The shedding of an outer integument or layer of skin, as by insects, crustaceans, and snakes;
molting.
Ecdysone
A steroid hormone that triggers molting in arthropods.
Ecological efficiency
The ratio of net productivity at one trophic level to net productivity at the next lower level.
Ecological niche
The sum total of an organism's utilization of the biotic and abiotic resources of its
environment.
Ecological pyramid
A graphic representation of the quantitative relationships of numbers of organisms,
biomass, or energy flow between the trophic levels of an ecosystem. Because large amounts
of energy and biomass are dissipated at every trophic level, these diagrams nearly always
take the form of pyramids.
Ecological species concept
The idea that ecological roles (niches) define species.
Ecological succession
Transition in the species composition of a biological community, often following ecological
disturbance of the community; the establishment of a biological community in an area
virtually barren of life.
Ecology
The study of how organisms interact with their environments.
Ecosystem
A level of ecological study that includes all the organisms in a given area as well as the
abiotic factors with which they interact; a community and its physical environment.