Final answer:
Decomposers break down dead organisms and return nutrients to the ecosystem, playing a crucial role in its stability and survival.
Step-by-step explanation:
Decomposers play a crucial role in an ecosystem by breaking down dead organisms and returning nutrients to the environment. They break down the remains and waste products of organisms, releasing simple inorganic molecules back into the ecosystem. This recycling of nutrients is essential for the survival and stability of the ecosystem. Without decomposers, the accumulation of dead organisms and waste would lead to a lack of nutrients for producers and other organisms, ultimately affecting the entire ecosystem.