What is the main environmental benefit of trees?

The main environmental benefit of trees is that they improve air quality and provide oxygen. Trees play a crucial role in the process of photosynthesis, where they absorb carbon dioxide from the atmosphere and release oxygen as a byproduct. This not only helps to replenish the air we breathe but also contributes to reducing greenhouse gases, which are a significant factor in climate change. Moreover, trees can trap airborne pollutants like dust, smoke, and other particulates, thus improving overall air quality. By producing oxygen and absorbing carbon dioxide, trees are vital in creating a healthier and more sustainable environment for all living organisms.

While the other options mention important benefits of trees, such as providing shade, serving as habitats for wildlife, and preventing soil erosion, they do not directly relate to the critical and widespread impact trees have on air quality and oxygen production, which are foundational to life on Earth.