Most of these urban stresses are caused by people, and often through ignorance. Here are some of the problems and what to do about them. Building and road construction are major causes of tree injury. Damage is done to the roots and trunk. Of the two, root damage is the more serious.
Damage can be direct or indirect.
Direct damage results from construction equipment hitting tree trunks, digging up roots, or riding over roots. Indirect damage is covering roots with fill, concrete, or asphalt. This changes the amount of water and oxygen that is available to the trees and smothers them. In some cases, toxic gases can build up and kill a tree. Symptoms are not immediately evident.