The biological significance of decomposers in an ecosystem lies in their role in nutrient cycling. Decomposers, including bacteria and fungi, break down dead organic matter, returning essential nutrients such as nitrogen and phosphorus to the soil. This process enriches the soil, promoting plant growth and maintaining the balance of the ecosystem. Decomposers also help in the reduction of waste and play a key role in the energy flow within food webs. Their activity is critical for sustaining health in ecosystems and supporting biodiversity.