Urban Streets Trees Sensitivity and Vulnerability to Low Voltage Overhead Power Lines

Urban green spaces as play an important role in dealing with environmental pollution and because of visual and aesthetic aspects of the cities have particular importance. Trees are one of the key elements of green spaces which planted in most urban streets and preservation, maintenance and development of them are always one of the main programs of municipalities. Trees planted in urban streets are threatened by various risks, such as bioecological factors (pathogenic microorganisms, insects, mites, etc.), environmental factors (industrial and chemicals pollutions, etc.) and various physical factors. One of the physical factors threatening urban street trees is proximity and contact with low voltage overhead power lines. Following these contacts, tree becomes a path through which electric current flow. Superficial burns caused by this electrical current create the wounds around the point of contact. These wounds provide a good way for penetration of different pathogen species into the trunk and eventually lead to weakness and dry up the entire tree. Sometimes, continuation of power lines contact with trees as a result of tree growth is intensify so that urban green space officials are forced to severe prune and sometimes cut entire tree. This issue strongly affects scenic beauty. This study has been done by the aim of comparing the vulnerability of urban streets trees in contact with low voltage overhead lines in the city of Hamadan. The dominant tree species in contact with power lines are acacia, platanus, ash, pine, elm, maple and berry. Based on field studies, compared to other tree species, platanus tree is more vulnerable to electrical current flow. In some cases, the severity of damage to plantain near low voltage overhead lines was so great that officials were forced to remove it.