Transfer of energy and materials among organisms within ecosystems is the ultimate level of organization in nature, Energy and materials, are required to construct and to maintain life, and their incorporation into biological systems is called productivity. Productivity is divided into component trophic levels based on how organisms obtain energy and materials.
Producers form the first trophic level:
a. Herbivores or primary consumers eat upon the producers and form the second trophic level.
b. Herbivores are in-turn eaten by different categories of carnivores forming the higher trophic levels.
c. Grazing food chains are longer food chains and they always end at decomposer level.
The detritus feeding organisms process the making organic material available for bacterial detritus in their gut by reducing it into small or fungal attack. These microorganisms also pieces, digesting it partially or completely, thus act as food for many soil animals.