What role does cohabitation of species play in the biological cycle?

For the cycle of substances, it is necessary for producers, consumers and decomposers to live together (i.e., cohabitation of different species), producers, which include chemosynthetic bacteria and all green plants, absorb substances from the surrounding nature, converting them from inorganic into organic, and transfer them further along the food chains, consumers are herbivores, carnivores, and decomposers (bacteria, fungi) return substances to nature, converting them from organic to inorganic.