As a major source of oxygen gas production of oxygen gas is gas ecosystem that living organisms must be used to break up food. To create or use in the process of breathing.
Produce oxygen sensitive ecosystems. Oxygen is a gas, the creature must be used to break down food. Or used to generate energy in cellular respiration.
Production is a source of oxygen gas important ecosystem. Oxygen is a gas which living organisms used to disperse the food. To create the energy or use in the breathing process