Some laws may only apply to fee for services work, or not. Call them and ask.
In my City, they said that they did not want homeowners getting hurt or hacking up trees that are hard to replace. Takes a lot of years for a large tree to grow, and only a few minutes for someone to hack it in a way that damages its growth. Even on private property, it could affect the character/value of the neighborhood, hit utilities, etc. Might not stand up to a court challenge, but that was their rationale. And boulevard trees belong to the City, except that the homeowner has to maintain the boulevard, but can't trim the trees, . . . . !
philbert