Question

​How is the 'flow of energy' different from the 'flow of nutrients' in an ecosystem?

Answer 1

Energy enters an ecosystem and leaves while nutrients are recycled. For example, plants get energy from the sun and use it to make sugar. Animals eat the plants, other animals eat those animals, animals die and eventually all of the energy is lost as heat. It has a definite entrance and exit. Nutrients on the other hand, such as essential minerals, already exist in the ecosystem, in the soil, the organisms and the air. Plants absorb nutrients, animals eat them, but when the organism dies and is decomposed, the nutrients stay behind and are simply used again. It never goes anywhere.