What is the ecological role of food chains and food web

Food web is an important ecological concept. Basically, food web represents feeding relationships within a community (Smith and Smith 2009). ... In a detrital food chain, dead organic matter of plants and animals is broken down by decomposers, e.g., bacteria and fungi, and moves to detritivores and then carnivores.

Hope this helps ^_^

i am going to guess that it is co2.