Physical decomposition of dead material and the role of decomposers in an ecosystem are similar in that they both involve the breakdown of organic matter. Both processes involve the breakdown of complex organic molecules into simpler compounds, such as carbon dioxide and water.
However, they are different in terms of the agents involved. Physical decomposition is a natural process that occurs through the action of physical and chemical processes, such as heat, humidity, and oxidation. Decomposers, on the other hand, are living organisms such as bacteria, fungi, and insects that consume and break down dead plant and animal material.
If there were no decomposers in a desert, the dead animal would not decompose as quickly as it would with the presence of decomposers. The physical process of decomposition would still occur, but it would be slowed down significantly due to the arid conditions of the desert. Eventually, the animal would be reduced to a skeleton and the process of physical decomposition would be complete.