Trophic efficiency incorporates three types of

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Trophic efficiency incorporates three types of efficiency: Proportion of available energy that is consumed ( consumption efficiency ). Proportion of ingested food that is assimilated ( assimilation efficiency ). Proportion of assimilated food that goes into new consumer biomass ( production efficiency ). Endotherms digest food more completely than ectotherms and thus have higher assimilation efficiencies. The “bottom-up” view: Resources that limit NPP determine energy flow through an ecosystem. The “top-down” view: Energy flow is governed by predator consumption rates at the highest trophic level, which influences multiple trophic levels below them. Trophic cascade : A series of trophic interactions that result in changes in biomass and species composition. Predation by a top carnivore (fourth level) decreases abundance of third level carnivores, which leads to an increase in herbivores (second level), and then a decrease in primary producers. Interaction strength : Measure of the effect of one species on the population size of another species. keystone species concept is important in conservation. It implies that protecting a keystone species may be critical for protecting the many other species that depend on it. Some chemicals are not metabolized or excreted, and become progressively more concentrated in tissues over an organism’s lifetime- bioaccumulation . Concentration of these compounds increases in animals at higher trophic levels, as animals at each trophic level consume prey with higher concentrations of the compounds. This process is known as biomagnification.
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