No, mushrooms are not autotrophs. They are heterotrophs, which means they cannot produce their own food through photosynthesis like plants do. Instead, mushrooms obtain their nutrients by decomposing organic matter. They secrete enzymes that break down complex organic materials into simpler compounds, which they then absorb as food.
This process of obtaining nutrients makes mushrooms an essential part of the ecosystem, as they help recycle nutrients by breaking down dead plants and animals. Without mushrooms and other decomposers, the environment would be overwhelmed with dead organic matter.