Carbon dioxide
this is the answer
The flow of energy in an ecosystem is best described as energy moving in one direction from the sun to the producers then to the consumers.
Explanation;
Energy flow is the amount of energy that moves through successive trophic levels of a food chain in an ecosystem. Ecosystem maintain themselves by cycling energy and nutrients.
The energy from sunlight is taken up by producers which use it to produce organic compounds through photosynthesis. The energy is then passed successively to the trophic levels, that is from the producers to the consumers ( primary, secondary, tertiary and quotienary consumers). During this transfer some energy is lost at each trophic level in form of heat.
