Cycle of matter and energy flow
To perform its vital functions, living things need a constant supply of matter and energy. All energy used by living things from the sun ecosystems .
Plants get energy directly from the sun through photosynthesis.Animals get energy from the food they eat, whether plant or animal.By respiration, both plants and animals use the energy, but part of it dissipated as heat, which passes to the external environment.Therefore, the flow of energy through an ecosystem is unidirectional .
Some microorganisms transform dead organic matter in mineral salts.The salts are used by autotrophic organisms and autotrophic organisms are ingested by heterotrophs. Then both heterotrophs autotrophs as they die and their remains are transformed by microorganisms, beginning the cycle again. Thus, the circulating material in the ecosystem cyclically.