296 O'Herrin et al.: Homebuilder Practices and Perceptions on Wooded Lots sensus on this topic (Watson 1998; Watson et al. 2014b). Builder understanding of the structure of tree root systems was generally poor with only 11% believing that tree roots generally extend away later- ally from the tree beyond the dripline, which could have dangerous implications for trees on construc- tion sites. This knowledge was inconsistent with Day et al. (2010a), who found that tree roots can extend several times the height of a tree away from the stem. Even though tree height is commonly used to provide a lateral extent of tree root sys- tems, tree diameter appears to be a better predictor (Day et al. 2010a). There was a significant decrease in the number of builders believing that applica- tion of nitrogen was helpful to tree recovery from root loss. Fertilization during and at least one year aſter construction should be modest at most, unless a nutrient deficiency exists (Harris et al. 2004). Activities Despite some minor improvement in their knowl- edge, builders in this study still commonly engaged in activities potentially detrimental to the successful preservation of trees on construction sites, such as storing building materials near the base of trees, us- ing heavy equipment near the base of trees, placing sidewalks within 3 m of trees, and trenching for util- ities. Other detrimental activities, such as bringing in fill soil to raise the grade of a site and storing soil near the base of trees, have both increased signifi- cantly since 1980. This was all despite scoring very highly on questions regarding soils, making improve- ments since 1980 on questions regarding damage to root systems, and rating the avoidance of excessive fill soil over tree root systems as the second most important tree preservation decision (index 4.04). Raising the grade of a site could be done for a variety of reasons, such as to facilitate a walkout basement. It could also be done to facilitate raising the grade above a seasonal flooding issue. In the study area, much of the development occurs in well- drained outwash sand plains and moraines, which were both artifacts of glacial activity that ended approximately 10,000 years ago (Clayton et al. 2006). The western part of the study area has older soils that were untouched by the last glacial period, have greater clay content, and drain more poorly, which can result in seasonal flooding. In this situ- ation, raising the grade during development could ©2016 International Society of Arboriculture account for a change in the builder response to this question. However, development in the well-drained sites was as common in this study as it was in 1980. Excavation within the critical root zone can lead to declining and dead trees (Fite and Smiley 2008a). Very few builders (7%) in 2008 reported placing foundations within 3 m of trees. In 1980, over 60% did such. This significant reduction (P < 0.000) with few builders excavating soil within 3 m of trees could be the result of selective placement of buildings or the preemptive removal of trees deemed too close for survival. This result might also apply to placement of driveways and sidewalks. But it was not known if this was because driveways and sidewalks are moved during the planning stage or if the trees were sim- ply removed more oſten. Smiley (2008) found that trenching cuts made closer than three times the stem diameter away from willow oak (Quercus phellos L.) took less force for tree failure. Thus, the recommen- dation with trenching is to stay at least three times the diameter or more away from the stem. Thus, if builders from this study stayed at least 3 m away with root severing, then assuming a similar out- come as with willow oak, tree stability would likely be insignificant for trees up to 100 cm in diameter. If root disruption does occur on one side of the tree and a distance of 3 m or more away is maintained, an effect of greater tree death or reduced tree health was less likely (Hauer et al. 1994; Koeser et al. 2014). It is possible that the lack of painting of wounds of oak trees by over 60% of the builders is an arti- fact of messages since the 1970s and 1980s that say painting tree wounds is not beneficial and can exac- erbate tree decay (Shigo and Shortle 1983). Apply- ing a wound dressing and proper pruning using the cut promoted by Shigo reduced the chance of oak wilt when a tree is pruned or wounded (Camilli et al. 2007). In the Midwest, many edu- cational approaches (e.g., billboards, public service announcements, brochures, newspaper articles, workshops) exist to educate professionals and laypeople about oak wilt management (Miller et al. 2015). Avoiding wounding of oak trees, and if wounding occurs covering the wound immediately (paint is oſten suggested), are two main points. Builders are either not motivated to change their activities, have little financial incentive, and/or lack training on alternative construction methods con- ducive to the effective preservation of trees. Despot
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