Have you ever walked downtown and took the time to look Up, down, and around? We are hurting the trees as a society. We have calculated how far the root system reaches. All the trees roots reach a far ways under the asfault. This isn’t healthy for tree because this means the only place it is able to get water is at the base of of it. Another is have you  ever walked downtown or somewhere where the trees are planted in the sidewalk?  Did you notice the sidewalk rise up or cracked? Not only is it a  safety hazard for us its not healthy for the tree either. The roots are compacted and this constricts growth.