is most of earth's oxygen made by trees?

Answer 1

It is estimated that between 70% and 80% of the oxygen in the atmosphere is produced by marine plants . Nearly all marine plants are single celled, photosynthetic algae.

Answer 2

There was some oxygen in the air anyway, even before plants evolved. But green plants, including trees especially because they are so big, are the ones that control the oxygen supply these days. So I won't answer for sure with regard to trees only, but if you count all the green plants (it's the chlorophyll that does it) then yes, the majority of the oxygen is released by them.

Answer 3

Plants yes, trees probably not.
I believe most of the oxygen is produced by algae or plankton in the oceans.

Answer 4

And don't forget about cyanobacteria - they are also common photosynthesizers with a large biomass and can exist on land in the lichen association. About 2% of the oxygen in our atmosphere comes from the UV breakdown of water.

Answer 5

A correction for Grey Fox's answer. Oxygen is "made" from water, not from carbon dioxide. That is, free oxygen is released when water is split in photosynthesis.

Answer 6

no, but since oxgygen tends to be produced from carbon dioxide, anything that stores carbon is a good thing for oxygen, and trees store huge quantities of it in their trunks.

most oxygen is made from green things in the ocean, sucha s phytoplankton.

Answer 7

No, by far the vast majority is made by oceanic plant life, algaes, mosses primarily.

Answer 8

no phytoplankton does

emerging science indicates that trees may give off co2 at night