Answer:
Living and nonliving things
Step-by-step explanation:
Energy Flow Through an Ecosystem. Trophic levels provide a structure for understanding food chains and how energy flows through an ecosystem. At the base of the pyramid are the producers, who use photosynthesis or chemosynthesis to make their own food. Herbivores or primary consumers, make up the second level. Our ecosystem is maintained by the cycling energy and nutrients obtained from different external sources. At the first trophic level, primary producers use solar energy to produce organic material through photosynthesis.