This energy transfer from one species to another can continue several more times, but it eventually ends. It ends with the dead animals that are broken down and used as food or nutrition by bacteria and fungi. As these organisms, referred to as decomposers, feed from the dead animals, they break down the complex organic compounds into simple nutrients. Decomposers play a very important role in this world because they take care of breaking down (cleaning) dead material. There are more than 100,000 different types of decomposer organisms! These simpler nutrients are returned to the soil and can be used again by the plants. The energy transformation chain starts all over again.

A food web is made up of interrelated food chains. Many animals and plants share the same habitat and they all live happily together. Nature balances things so that the food webs last a long time.

Energy begins with the sun. It helps make the grass grow. The grass is a producer because it provides food for many animals. The grasshopper is a consumer and eats the grass. The snake consumes (eats) the grasshopper and is then eaten by the hawk. When the hawk dies, his body is broken down into nutrients (food) by fungi which is a decomposer. This provides nutrients for the grass. The food chain is a cycle of energy.

The following illustration shows a simplified food web in a marsh ecosystem