The value of a tree

We totally should take care of trees. They are an important part of our ecosystem and they contribute to our lives too. That said- this figure is quite dubious. “$X in oxygen”... based on what? The cost to refine oxygen from water? To great oxygen molecules in a particle collider? The market value of oxygen? Which in itself is a bit misleading since oxygen follows the law of supply and demand, and thusly the more we have of trees, the less market value would be placed on atmospheric oxygen- which would therefore make the formula self defeating. Take care of trees or most of us probably die. The end.