It’s been proven that humans didn’t actually get most of their fresh air from the rainforest, but actually from millions of these algea in the sea… Which is actually more logical, since trees do the opposite at night, kinda undoing any advantage they made during the day… Hence why it’s said you should never put a decorative small tree or even plants in the bedroom as they can take away oxygen levels in closed rooms at night. It’s even said not to sleep under trees outside at night cause it can cause respiratory problems.