Answer:
Decomposers are critical in the nitrogen and phosphorus cycles because they are involved in processes that return the nutrients to their major reservoirs.
The process by which phosphorus cycles through the biosphere is called fixation. This process involves the conversion of inorganic phosphorus compounds, such as phosphates, into organic forms that can be used by plants and other organisms. This process is typically carried out by bacteria, fungi, and other decomposers, which break down organic matter and release the nutrients back into the environment.