Producers, consumers, decomposers কী?

The organisms of an ecosystem are grouped by what they eat into trophic levels. Producers (autotrophs: plants, algae, cyanobacteria, chemosynthetic bacteria) make organic matter from inorganic; they are the first level. Consumers eat it: primary consumers (herbivores) eat producers, secondary consumers (carnivores) eat herbivores, tertiary consumers eat carnivores; omnivores eat at several levels. Decomposers (bacteria, fungi) and detritivores (earthworms, woodlice, dung beetles) live on dead matter and wastes from every level, and return its minerals to the soil and water for the producers to take up again — the link that closes the cycle of matter.