Decomposers
The degradative processes that fungi perform with their extracellular enzymes are essential to the terrestrial biosphere. They are the main agents of decay of cellulosic wastes produced by plants, which in the tropical rain forest can amount to 12 000 kg hectare-1 year-1. They decompose this material into CO2, H2O, and fungal biomass, which in turn is decomposed by other microbes, returning mineral nutrients like phosphorus, nitrogen, and potassium to the biosphere. This process is termed mineralization.