The selection of an urban tree is much more complex than the typical tree.  There are many factors that are involved in successfully choosing which tree works best in the urban fabric.  The following are some of the factors in selecting the appropriate tree in an urban setting:  Form; Branch Structure; Root Structure; pH Tolerance; Pollution Tolerance; Tree Litter; Water and Sunlight Requirements; and Aesthetics.
Full Story: Urban Tree Selection

The form of a tree is a primary consideration in an urban environment. Sketch by John Olson.