What are decomposer ? What will be the consequence of their absence in an ecosystem ?

Explanation

Decomposers include microorganisms such as bacteria and fungi that obtain nutrients by breaking down the remains of dead plants and animals. It breaks down the complex organic substances of garbage, dead animals and plants into simpler inorganic substances that go into the soil and are used up again by the plants.
The absence of decomposers recycling of material in the biosphere will not take place.