a mushroom is a kind of fungus & in the food chain process fungi have the role of decomposer ->  in the food chain process a mushroom has the role of decomposer  decomposer is a kind of role in the food chain process / in an ecosystem & decomposition is when a decomposer breaks down dead organisms ->  the role of a decomposer is to break down dead organisms  in the food chain process a mushroom has the role of decomposer & the role of a decomposer is to break down dead organisms ->  the role of a mushroom is to break down dead organisms  the role of a mushroom is to break down dead organisms & a plant is a kind of organism -> the role of a mushroom is to break down dead plants