. Animal Ecology. Animal ecology. 3 ./f 'quaternary consumers {C4) TERTIARY CONSUMERS (Cj). TRANSFORMERS (T) PRODUCERS (P) FIG. 14-2 Energy flow through an ecosystem the trophic levels of which are in balance with each other; symbols are explained in text. The weights of the arrows are intended to suggest the relative proportions of energy flow in the various directions, but this is schematic because the proportions vary widely in different ecosystems. Certain of the food taken in, I, is indigestible or may simply be undigested, or if digested and ab- sorbed is not completely metabolized in th
. Animal Ecology. Animal ecology. 3 ./f 'quaternary consumers {C4) TERTIARY CONSUMERS (Cj). TRANSFORMERS (T) PRODUCERS (P) FIG. 14-2 Energy flow through an ecosystem the trophic levels of which are in balance with each other; symbols are explained in text. The weights of the arrows are intended to suggest the relative proportions of energy flow in the various directions, but this is schematic because the proportions vary widely in different ecosystems. Certain of the food taken in, I, is indigestible or may simply be undigested, or if digested and ab- sorbed is not completely metabolized in the tissues, so that it is eliminated in feces and excreta. This is designated excretory energy, E. Assimilated energy is the energy of the food actually absorbed and uti- lized (/ — E). These terms may also be applied to the producer level when / represents the total solar radiation reaching the plant, and E is that portion of the radiation not used. Aside from being killed by predators, organisms die from a multitude of other factors such as disease, extreme weather, starvation, combat, old age, and accident. In order for the populations of the different trophic levels to be maintained at a more or less con- stant level, organisms that die non-predatory deaths, D, must be replaced by the reproduction and growth of new individuals. For energy to be transferred from one trophic level to a higher one, organisms must be killed and eaten by predators of the higher trophic levels. When predators consume their prey completely, as do fish feeding on plankton, there is no wastage, but with many predators, the prey killed is so large it must be eaten piecemeal, and much is not used. Predatory kill must therefore be separated into the energy con- sumed by the higher trophic level (/a+i) and the energy wasted, W. Energy lost from a trophic level through excreta, non-predatory deaths, and wastage from kills is used by saprovores or transformers, T. This allows for the decomposition and co
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Keywords: ., bookcentury1900, bookcollectionbiodive, booksubjectanimalecology
