Any tree care firm, city department, or public utility shall use acceptable techniques when pruning street or park trees. Descriptions and diagrams of acceptable pruning techniques will be described and more fully explained in the comprehensive tree management plan called for in section 7-2-4 of this chapter. It shall be unlawful for any tree care firm, city department or public utility to top any street tree or park tree. "Topping" is defined as the severe cutting back of limbs to stubs larger than three inches (3") in diameter within the tree's crown to such a degree so as to remove the normal canopy and disfigure the tree. Trees severely damaged by storms or other causes, or certain trees under utility wires or other obstructions where other pruning practices are impractical may be removed or exempted from this section at the determination of the city tree board. (Ord. 1014, 10-2-2001)