The decay cycle: reduces the amount of dead material returns oxygen to the atmosphere cannot happen without fungi all of the above

reduces the amount of dead material

Explanation:

Decay cycle refers to breakdown of complex organic matters present in dead and decaying plant and animal bodies into the simpler substances. Decomposers are the microbial heterotrophs and include fungi as well as bacteria. They serve in decay cycle. The process uses oxygen and lack of oxygen slow down the decay cycle. It does not allow the dead organic matter to build up in the system.