There are two types of food chains, namely, the detritus food chain and the grazing food chain. In 1927, he recognized that the length of these food chains was mostly limited to 4 or 5 links and that food chains were not isolated, but were engaged in food networks (which he called food cycles). In this food web, grasshoppers feed on plants; scorpions feed on grasshoppers; common foxes feed on scorpions. Therefore, the final product of detritus food chains includes carbon dioxide and inorganic compounds such as nitrates, sulfates and phosphates.
In this example of a predatory food chain, phytoplankton are primarily responsible for the production of food (or organic matter) through photosynthesis. The fox, a carnivore and heterotrophic, unable to produce its food on its own, depends on obtaining energy by feeding on the rabbit. In a grazing food chain, energy and nutrients pass from plants to herbivores that consume them and to carnivores or omnivores that feed on herbivores. For example, this type of food chain operates on accumulated decomposing garbage in a temperate forest.
This type of food chain starts from dead organic matter, which is fed by microorganisms, to organisms that feed on detritus and their predators. Organisms ranging from bacteria and worms to the noble cockroach feed on the dead and, in doing so, break them down into the nutrients that keep the food chain running. The fundamental purpose of food webs is to describe the feeding relationship between species in a community. As a diagramming tool, the food web has been approved to be effective in illustrating species interactions and testing research hypotheses.
All species in food webs can be distinguished into basal species (autotrophic, such as plants), intermediate species (herbivores and intermediate-level carnivores, such as grasshoppers and scorpions) or major predators (high-level carnivores, such as foxes) (Figure. In conclusion, a food chain, usually a theoretical representation of how energy is transferred from one level of one ecosystem to another, can, at best, be described as dynamic. They are capable of producing food through the process of photosynthesis, using the chlorophyll in their leaves and stems in the presence of sunlight. While the food web shown here is simple, most food networks are complex and involve many species with strong and weak interactions between them (Pimm et al.