Trees growing within cities and towns form a forest-an urban forest. But urban trees require special attention, because they are expected to exist within the urban environment. With its infrastructure of streets, sidewalks, curbs, buried utilities, overhead power lines and buildings, the urban environment places tremendous stresses on trees. With proper care, trees become assets which grow in value over time. Without care, tree value declines, eventually becoming a liability to the community. The Technical Guide to Urban Forestry was produced to help communities develop, manage and protect their urban forest resources. The purpose of this publication is to provide technical information about growing trees in the relatively adverse urban environment. This guide is a sequel to An Introductory Guide to Community and Urban Forestry in Washington, Oregon and California. The two publications have been designed to complement each other. Together they provide introductory and technical information regarding urban forestry programs and projects. Both guides were produced in response to requests from local officials and professional tree managers. The need for tree management is never clearer than when urban development eliminates a significant stand of trees, or even a single well placed specimen. Sometimes trees are lost inadvertently, resulting from a lack of information. For example, roots are a tree's most vulnerable part, yet heavy equipment routinely runs over roots. By the time the tree starts to show signs of physical deterioration, five to ten years may have passed. Other times trees are killed intentionally as developers "land-scrape" before construction. This approach portrays an attitude that trees have little or no value in developed areas, Those who guide local development need to understand urban stress factors and the role they play in the premature death of trees.

The topics covered in this guide include: tree values, principles of tree growth, planning, tree selection, site preparation, planting and early care of trees, maintenance of established trees, handling trees affected by development, utility forestry, and the politics of municipal tree care. This guide is intended for use by citizens, government decision makers, land developers, and workers out on the streets. Like the original Introductory Guide, this Technical Guide is written for anyone in the private or public sectors who cares enough about their environment to see that trees in their community are planted, valued and protected. The Technical Guide was written by a team of professionals identified on the last page. This group of researchers, educators and practitioners from throughout Washington, Oregon and California are dedicated to providing information on the urban forest resource. Their volunteer efforts reflect the need for people everywhere to contribute their energy and knowledge to make cities more livable for trees.

Tree pruning involves not only knowledge of tree growth, but technical expertise with equipment and supplies as well as strength and athletic agility.

Sponsors U.S. Department of Agriculture, Forest Service, Pacific Northwest and Pacific Southwest Regions Washington State Department of Natural Resources Oregon Department of Forestry California Department of Forestry and Fire Protection Produced by World Forestry Center in Portland, Oregon and Robin Morgan, Urban Forestry Consultant Revised Edition March 1993 Original Publication September 1989 A Technical Guide to Urban and Community Forestry in Washington, Oregon and California