If trees are removed from rainforest what happens to amount of water and oxygen

Well, trees need water to live so they can create oxygen, so one would think that the amount of water goes up and the amount of oxygen goes down

We need trees, that's why it's called a forest. Tress are nature also a natural thing and water and oxygen are also a natural thing that humans need. If trees are removed, then the water from lakes will get dirty, as for the oxygen we need from the tree, we humans need water and oxygen, so trees are needed.