Trophic Efficiency

∞ generated and posted on 2016.12.21 ∞

Ratio of consumer-species secondary productivity to the productivity supplied by the consumer's food.

Trophic Efficiency is a description of how effectively organisms convert their food into more mass (i.e., weight) of their own body.

In other words, how much of what a consumer ends up being stored as a part of the consumer? Trophic efficiencies on a per-consumer species basis – or, indeed, per consumer-consumed pairing – generally range from about 5% to 20%.

That is, from 95% down to 80% of the energy and carbon associated with a primary producer is lost in terms of conversion to secondary consumer's body (from from a secondary consumer to a tertiary consumer, etc.).

These inefficiencies arise not just because of the consumer's needs, as well as the second law of thermodynamics, but also because the efficiency of digestion is not 100%. That is, in particular represent a fraction of an animal's food that, mostly by definition, does not end up being stored as a part of the animal's body.

(I say "mostly by definition" because there are animals, such as , that consume their own feces, so-called .)

At least for the lowest of trophic interactions, trophic efficiency can be restated as the ratio of secondary productivity to consumed primary productivity.

Contrast with production efficiency and see more generally the concept(s) of . See too pyramid of productivity as well as .


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