174 Kulhavy et al.: Comparison of Tree Condition and Value in Texas, U.S. to the university, and would increase to $35 mil- lion for all trees in optimum condition. However, there is $7 million reduction in potential value (29%) because of imperfect condition. A distinc- tive characteristic of urban forests is that when they mature, more maintenance is required. The results indicate that many campus trees currently receive less maintenance than needed. McPherson et al. (1999) indicate investment in the urban forest offers return to the citizens, and continued invest- ment is needed. Planning and managing for the future will require careful planning and the devel- opment of a long-term urban forest management plan. A concerted effort is underway to remove hazard trees from the campus and to increase tree maintenance based on the results of this study. The replacement value method is extremely use- ful when planning for tree removal, site cleanup, res- toration, preparation, and additional maintenance expenditures. The demands to quantify the value of trees become even more important when trees are threatened by disease. Ellison (2005) indicated the need to balance the benefits of risk reduction with the associated costs of lost tree value and financial expenditure. Evaluating and mapping the tree pop- ulation and identifying the interface between trees and targets prioritize risk assessments. The mea- surements of the tree condition in the current study can be used in risk assessment. Trees with lower condition values (Table 1; Table 2) indicate trees at greater risk. Risk includes dead or dying branches (Structure) while trunk defects include cracks and sporophores (Trunk). These trees require careful monitoring to ascertain further loss of condition. The value of these trees added to an ArcGIS 10.1 database provides the basis for future comparisons on an annual examination. As both of the study areas investigated are high traffic areas, both the proxim- ity of the trees and target evaluation need to be con- sidered. More frequent inspections of areas of high public access need to be considered with updates to the hazard rating data (Hickman et al. 1995; Ellison 2005). Hazard rating of campus and park trees needs to include the “prudent person” concept (Sharon 1987) for one that looks ahead and carefully pro- vides for the future. Values, such as the cost to main- tain declining trees and the removal of trees that have been killed by disease, can be derived based on the calculated dollar values. If the values people are ©2014 International Society of Arboriculture paying for the trees need to be evaluated, another modeling method, predictive modeling, would be better to reflect those values (Martin et al. 1989). More specialized soſtware used for urban forest evaluation and management have been developed and widely used for professional GIS application with powerful database and GIS mapping tech- niques. Some advanced soſtware, including Tree- Pro™ and CITYgreen, are designed to archive tree data and allow for tree evaluation in a more con- venient way. Longcore (2004) conducted a case study in Los Angeles, California, U.S., in 2004, with CITYgreen soſtware. Based on a geographic repre- sentation of the study area, Longcore analyzed the benefits of trees and greenspace and pointed out some limitations, including that the tree growth model seems to work well on young trees, but calcu- lates unrealistically large future tree sizes for mature trees. Currently trees on the SFASU campus and in Nacogdoches city parks are being evaluated using i-Tree Design to determine benefits of the urban forest on rainfall interception, energy savings, ben- efits to air quality and carbon dioxide reduction. Abd-Elrahman et al. (2010) used i-Tree ECO to develop an urban forest inventory. This soſtware, using the standards set by the ISA, can track, value, and rate trees and generate reports containing assessed value, species, location, hazard rating, DBH, height, and maintenance history. With that, trees would be evaluated and managed more easily and efficiently. SUMMARY The SFASU campus trees were significantly healthier than the city park trees. Among the most abundant twelve species, nine species had significant differ- ence in tree health and showed significant difference in trunk condition. Trunk problems or wood decay were the most important factors concerning tree health condition. When using $75 as the ISA val- ue per square inch of cross-sectional area, the total value of all SFASU campus trees was over $27 mil- lion compared to over $20 million for the city park trees. However, SFASU campus trees had a lower average value than city park trees due to area sizes and different species composition. If all trees were in optimum condition, the total value of SFASU would increase to over $35 million, implying a 30% loss in dollar value due to the undesirable condition. In the city parks, if all trees were in optimum condition,
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