The major functions taking place in an ecosystem are productivity, decomposition, flow of chemical nutrients and flow of energy. → The abiotic decomposed material in the soil contribute nutrients needed for the ecosystem to function. → Energy is captured from the Sun by the producers, to convert inorganic abiotic material into organic compounds and supply food for other organisms or consumers in the ecosystem. (Productivity and nutrient cycling) → Energy is then used by consumers that eat the producers, or decomposers that break them down. (Flow of energy) → Some amount of energy is lost to the environment as heat → The decomposers break down dead material and convert all organic matter into carbon dioxide (which they respire) and nutrients which become part of the soil again. (Decomposition and nutrient cycling)