Given the fact that plants cannot do photosynthesis at night but need respiration for their energy needs, they use up oxygen and generate carbon dioxide. But how much is this? If I fill a room with plants thoroughly, what composition will the air in this room be in the morning? Are different plant species vastly different in this regard?
Roughly, half of the CO2 assimilated annually through photosynthesis is released back to the atmosphere by plant respiration (Gifford, 1994; Amthor, 1995).
Furthermore, it appears like plant respiration rates do not change much with changing temperature, and that larger plants have higher respiration rates.