A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Another name for food web is a consumer-resource system, ecologists can broadly lump all life forms into one of two categories called trophic levels, 1) the autotrophs, and 2) the heterotrophs. To maintain their bodies, grow, develop, and to reproduce, autotrophs produce organic matter from inorganic substances and these chemical reactions require energy, which mainly comes from the sun and largely by photosynthesis, although a very small amount comes from hydrothermal vents and hot springs. The linkages in a food web illustrate the feeding pathways, such as where heterotrophs obtain organic matter by feeding on autotrophs, the food web is a simplified illustration of the various methods of feeding that links an ecosystem into a unified system of exchange. There are different kinds of feeding relations that can be divided into herbivory, carnivory, scavenging. Some of the organic matter eaten by heterotrophs, such as sugars, autotrophs and heterotrophs come in all sizes, from microscopic to many tonnes - from cyanobacteria to giant redwoods, and from viruses and bdellovibrio to blue whales. Charles Elton pioneered the concept of cycles, food chains. Elton organized species into groups, which was the basis for Raymond Lindemans classic. Lindeman emphasized the important role of organisms in a trophic system of classification. Even earlier, in 1768 John Bruckner described nature as one continued web of life, ecologists use these simplifications in quantitative models of trophic or consumer-resource systems dynamics. Using these models they can measure and test for generalized patterns in the structure of food web networks. Ecologists have identified non-random properties in the structure of food webs. Published examples that are used in analysis are of variable quality with omissions. However, the number of studies on community webs is on the rise. Scaling laws, for example, predict a relationship between the topology of food web predator-prey linkages and levels of species richness, links in food webs map the feeding connections in an ecological community. Food cycle is a term that is synonymous with food web. Ecologists can broadly group all life forms into one of two layers, the autotrophs and the heterotrophs. Autotrophs produce more energy, either chemically without the suns energy or by capturing the suns energy in photosynthesis
Image: Food Web
An illustration of a soil food web.
Victor Summerhayes and Charles Elton's 1923 food web of Bear Island (Arrows point to an organism being consumed by another organism).