Producers and consumers (herbivores, carnivores, omnivores, and decomposers) are related in food chains
Producers and consumers (herbivores, carnivores, omnivores, and decomposers) are related in food chains and food webs and may compete with each other for resources in an ecosystem.
Most texts provide the basic information about producers and the different kinds of consumers (herbivores, carnivores, omnivores, and decomposers). The California Science Framework (page 61) makes the important point that “decomposers, such as fungi and bacteria, should be included at each level of the food web as they consume the remains and wastes of plants and animals.” Diagrams of food chains, food webs and the ecosystem energy pyramid often mistakenly show decomposers acting at just one level.
Food chains are linear and are useful for introducing the general principle that plants capture the solar energy and are then eaten by an herbivore which, in turn, may be eaten by a carnivore or omnivore. Depicting the relationships in the form of a food web is generally more accurate since few organisms eat just one thing or are eaten by just one kind of organism. A food web is more useful for predicting the effects of a change on an ecosystem.