Please cite this article in press as: Koeser, A., et al., Factors influencing long-term street tree survival in Milwaukee, WI, USA. Urban Forestry & Urban Greening (2013), http://dx.doi.org/10.1016/j.ufug.2013.05.006 ARTICLE IN PRESS G Model UFUG-25354; No. of Pages 7 Urban Forestry & Urban Greening xxx (2013) xxx–xxx Contents lists available at SciVerse ScienceDirect Urban Forestry & Urban Greening jou rn al homepage: www.elsevier.de/ufug Factors influencing long-term street tree survival in Milwaukee, WI, USA Andrew Koeser a,∗ , Richard Hauer b , Kelly Norris c , Randy Krouse d a Department of Environmental Horticulture, IFAS, University of Florida – Gulf Coast Research and Education Center, 14625 County Road 672, Wimauma, FL 33598, United States b College of Natural Resources, University of Wisconsin-Stevens Point, 800 Reserve Street, Stevens Point, WI 54481, United States c Wyoming State Forestry Division, 600 Veterans’ Lane, Buffalo, WY 82834, United States d City of Milwaukee, 841 N. Broadway, Milwaukee, WI 53202, United States a r t i c l e i n f o Keywords: Construction damage prevention policy CTLA condition rating Tree longevity Tree mortality Street trees a b s t r a c t Street trees are exposed to a variety of site conditions, environmental factors, and physical disturbances which influence their survival in urban areas. This study draws on 25 years of urban forest monitoring data from the city of Milwaukee, WI (United States) to model the impacts of these factors on tree survival for a single cohort of trees. Tree condition, tree size, tree species, and site attributes were measured initially in 1979. These factors were measured again in 1989 and 2005 and compared to construction data for the same area during the study period. Multivariate logistic regression was used to identify factors associated with tree survival. Cross-validation show the final model could successfully predict tree survival nearly 85% of the time. Results indicate that tree survival varied by species. Additionally, trees were more likely to die as trunk diameter increased, planting space width decreased in the tree lawn, and tree condition decreased. Finally, trees adjacent to construction were nearly twice as likely to die as those not exposed to development and redevelopment activities. © 2013 Elsevier GmbH. All rights reserved. Introduction The economic benefits generated by an urban forest are greatly influenced by urban tree longevity. Depending on the location and valuation method applied, it may take one or more decades before the benefits of a newly planted urban tree equals the costs associ- ated with its installation and maintenance (Mcpherson et al., 1997). Unfortunately, construction activities near street trees can have sig- nificant impact on tree health and survival resulting in a loss in net urban forest value (Hauer et al., 1994). Understanding the many tree- and site-related factors that influence urban tree longevity in the presence and absence of construction activities is critically important for urban tree managers charged with maximizing net urban forest value. While street trees can potentially benefit urban infrastructure by reducing the maintenance demand of asphalt roadways through shading (McPherson and Muchnick, 2005), it is more common to find accounts of urban gray and green infrastructure in conflict (Hauer et al., 1994; Francis et al., 1996; McPherson, 2000; Randrup et al., 2001; Grabosky and Gilman, 2004; Celestian and Martin, 2005; Day et al., 2010a,b). As tree roots grow outward and expand, ∗ Corresponding author. Tel.: +1 8136334150. E-mail addresses: akoeser@ufl.edu, arborkoeser@yahoo.com (A. Koeser). pressure is exerted on adjacent soil and nearby infrastructure sur- faces (Grabosky and Nenad, 2011). This root pressure can lead to, among other things, sidewalk lifting (Francis et al., 1996; Randrup et al., 2001; D’Amato et al., 2002a; Grabosky and Nenad, 2011) and the widening of cracks or seams in foundations or pipes (Day, 1991; Rolf and Stål, 1994; Östberg et al., 2012). If street trees are respon- sible of these infrastructure damages, then the repair reduces the net benefit of street trees. Just as street trees can impact the functional lifespan of con- structed materials, their health, size, and ultimate longevity are also impacted by close proximity to infrastructure and site condi- tions (Hauer et al., 1994; Grabosky and Gilman, 2004; Celestian and Martin, 2005). Compacted base soil layers and impervious surfaces can reduce soil water, aeration, and root growth (D’Amato et al., 2002b; Grabosky et al., 2002; Grabosky and Gilman, 2004; Smiley et al., 2006). In addition to limiting rooting space, the replacement of damaged or worn out hardscape elements can cause significant mechanical injury and loss of stability, especially in instances where existing structural roots are severed near the trunk for trenching, road expansion, or curb replacement (Hauer et al., 1994; Smiley, 2009). Many factors beyond construction influence tree survival (Miller, 2007). A recent meta-analysis of urban tree longevity research found annual survival rates were approximately 94.9–96.5% (Roman and Scatena, 2011). Within this overall 1618-8667/$ – see front matter © 2013 Elsevier GmbH. All rights reserved. http://dx.doi.org/10.1016/j.ufug.2013.05.006