ecological efficiency The ratio between energy flows measured at different points in a food-chain, usually expressed as a percentage. Many approaches have been devised to relate different aspects, e.g. intake, assimilation, and production. Two main categories of efficiencies are studied:
a. those of energy transfer between different trophic levels; and

b. those of energy transfer within a single trophic level.

ecological efficiency The ratio between energy flows measured at different points in a food-chain, usually expressed as a percentage. Many approaches have been devised to relate different aspects (e.g. intake, assimilation, and production). Two main categories of efficiencies are studied: (a)those of energy transfer between different trophic levels; and(b)those of energy transfer within a single trophic level.

ecological efficiency (trophic level assimilation efficiency) The ratio between the energy assimilated at one trophic level and that assimilated at the immediately preceding level, usually expressed as a percentage; i.e. (A₂/A₁) × 100, where A₁ is the lower trophic level and A₂ the higher trophic level.