Several inventory systems have been developed by cities, universities, extension services, and consulting firms. They range from quick, inexpensive survey methods that provide basic information to sophisticated, computerized systems that are integrated with daily tree care activities. A Guide to Urban Tree Inventory Systems was developed by the School of Forest Resources at Pennsylvania State University in 1979. It contains a general review of the characteristics of urban tree inventory systems, as well as profiles of 25 systems and references to 24 other inventories. All inventories share the same general goal-to provide information about the nature of the urban forest.
Most inventories have several objectives.
The simplest systems might provide information to support the establishment of a tree care budget, start a community tree program, or at least, initiate a tree advisory board. Computerized systems may be used to justify and prepare annual budgets, organize daily work assignments, keep records on individual trees, aid long-range planning, and support management analyses. Long-range tree replacement or rotation plans should be based on inventory information. Because tree removal or replacement generates community concern, citizens and policy makers should both be involved in the process. Criteria for tree removal form the basis for objectivity in the midst of the emotional furor that often develops over tree removal in urban areas.