Answer: They convert dead organic compounds into reusable organic compounds.
Step-by-step explanation:
The main function of decomposers in the ecosystem is the decomposition and degradation of the dead organic matter generated from dead plants and animals into simple reusable organic substances in the soil, that can be absorbed by the plants readily. The absorption of these substances will help plants in obtaining energy for cellular metabolism. Hence, this way matter and energy get recycled in an ecosystem by the decomposers.