Answer:
Autotrophs
Step-by-step explanation:
They are the producers in the ecosystem.
Autotrophs are organisms that produce food food from sunlight or from inorganic substances via chemical processes.
They obatin their energy by converting very simple materials into complex and useful organic compounds for use in the ecosystem. One of such process is photosynthesis in which green plants uses sunlight and carbondioxide to produce glucose for their nourishment. Another of such process is chemosynthesis.
Most heterotrophs(consumers) relies on this source of energy for their own survival and nourishment.