Trees, like all living organisms, do not need oxygen in the way that animals do. They don't breathe oxygen to survive, but rather produce oxygen as a byproduct of photosynthesis.

Here's a breakdown of the process:

* Photosynthesis: Trees take in carbon dioxide (CO2) from the air, water (H2O) from the soil, and sunlight.

* Energy Production: They use these ingredients to create sugars (food) for themselves and release oxygen (O2) as a byproduct.

So, while trees don't *need* oxygen to breathe, they do release it into the atmosphere through photosynthesis. This oxygen is vital for animals, including humans, who use it for respiration.

It's a beautiful symbiotic relationship – trees create oxygen for animals, and animals release carbon dioxide that trees need to grow.