But the actual question I'm interested in is:
What is the ratio of oxygen produced during the day vs. consumed at night.
Even ballpark numbers are sufficient, as this came up in a conversation about a Mars colony game where a tree produced 2 units of oxygen during the day and consumed 1 at night (with the game-night being half the length of a game-day because...reasons). Colonists would then need about 1 to 1.5 oxygen per full day/night cycle.
My friend and I were like "this ratio does not sound right" and haven't been able to find any any decent numbers to back up our opinion...or refute it.
Obviously the chemical reactions involved are mirrors of each other, and the output depends on the amount of light, and so forth...But wouldn't trees just be...less active at night in order to conserve energy, while more active during the day?