energy becomes less efficient. This means that the amount of energy available at each successive trophic level becomes progressively less. Figure 4-13 shows a simplified example of energy movement. The original source of energy for a food chain, the sun, provides about 100,000 units of energy that plants capture and use for photosynthesis.
Plants are able to capture about 1 percent of the light energy (1,000 units). Primary consumers use about 10 percent of the plant biomass produced (100 units of energy). Secondary consumers capture and consume about 10 percent of the energy stored by primary consumers (10 units of energy). Finally, the tertiary consumers capture and con