Please note â€“ YOU CANâ€™T GET OXYGEN WITHOUT PRODUCING FOOD! Photosynthetic oxygen comes from the Carbon Dioxide consumed (and recycled) and the carbon must be removed as a product. Similarly the Amazon forests canâ€™t be â€œthe lungs of the planetâ€ (producing Oxygen) unless timber or other forest products are continuously removed. The Ocean can produce Oxygen continuously, as it has organisms which shed Carbonates into the depths (creating chalk and limestone eventually) or deposit it as coral. In a closed forest system, the Oxygen is reabsorbed by the decaying dead wood and litter with no net production.
To my unstudied understanding of chemistry and biology, that seem to make perfect sense. So all the greenies that are telling us we should leave the rain forests alone to protect our oxygen supplies are potential full of the proverbial.
What we really need is a sustainably managed forest resource, selectly harvesting trees and allowing new ones to grow. Interesting.