Producers, consumers and decomposers are the three main types of organisms in an energy pyramid. To see how decomposers fit into the energy pyramid, we need to change the idea of a pyramid to a cycle. Just like with all other types of energy transfer, the cycle begins with the sun. The light energy from the sun is transferred to the producer, which transfers energy on to the consumers and decomposers, as well as wasting some as heat energy which can't be used up. Likewise, the energy the consumers receive from the producers goes to the decomposers, with a small amount again being emitted as excess heat energy. The energy received by the decomposers from both the producers and consumers all goes into the inorganic nutrient pool, with a small amount wasted as heat again. To complete the cycle, the energy from the nutrient pool restarts the process when it's absorbed by the producers, and so on.
Decomposers are essential in the sense that they enrich soil with nutrients because of their ability to break down non-usable compounds into elements which can be easily absorbed by most plant species. If it wasn't for decomposers in the energy cycle, plants wouldn't be able to grow properly and there would be famine, as the nutrients required for healthy growth would be simply inaccessible and crops would quickly die. There'd also be rotten dead animals everywhere because of a lack of decomposers to feed on them and cause them to decay.
Decomposers are essential in the sense that they enrich soil with nutrients because of their ability to break down non-usable compounds into elements which can be easily absorbed by most plant species. If it wasn't for decomposers in the energy cycle, plants wouldn't be able to grow properly and there would be famine, as the nutrients required for healthy growth would be simply inaccessible and crops would quickly die. There'd also be rotten dead animals everywhere because of a lack of decomposers to feed on them and cause them to decay.
