ABSTRACT
The collection of solar energy needed to power the entire ecosystem depends directly on plants. Plants themselves depend on solar energy to meet their own energy needs. Of the total energy collected, they use about 25% for respiration, 35% for building and maintaining structure, and 35% for reproduction (Figure 5.2). Plants also produce a small surplus of energy that is used by consumers. Some animals and microorganisms feed directly upon the plant population, but others obtain their energy by feeding on fi rst-order consumers. A relatively small amount of energybetween 5% and 10%—moves from one level to the next in the food chain (Pimentel, 1988).
