If an organism converts energy in the environment into food, what is the ecological role of the organism?

I'm guessing that's a decomposer.

Explanation:

Decomposers like mushrooms use dead animals, plants, and nutrients in their environment to make their own food.

oxygen +1 most likely

some fungi obtain their nutrients from a living host (plant or animal) and are called most biotrophic fungi have fairly narrow host ranges—they are specialized on a limited called rhizomorphs that allow the fungus to grow from one tree to another. ascospores are formed inside a sac-like structure called an ascus. so your answer is a