Nutrient Cycling

Unlike energy, the chemical elements that make up living organisms are finite and must be reused. Biogeochemical cycles describe how elements such as carbon and nitrogen move between the atmosphere, oceans, rocks, soil, and living organisms. Decomposers are central to these cycles because they release locked-up nutrients from dead matter, making them available again for producers.

The Role of Decomposers

Decomposers, mainly bacteria and fungi, secrete enzymes that digest dead organisms and waste products externally, then absorb the released molecules. This process, called saprotrophic nutrition, returns carbon dioxide to the atmosphere and mineral nutrients such as nitrates and phosphates to the soil. Without decomposers, nutrients would remain trapped in dead tissue and ecosystems would g