Determination of Tree Mortality Rate in Public Urban Areas at Early Stages After Planting

Abstract

Measuring urban tree mortality rates during the first several years after planting is a growing field of study for urban forestry practitioners. Mortality rates for timber species in forest stands have been measured extensively over time, but stand level mortality research in urban forests has remained localized and isolated until the 1990’s. By concentrating research in this area, practitioners will be in a better position to understand the best practices for urban forest management in response to different conditions and methods. The city of Baltimore, in Maryland, USA, has been collecting tree planting records since 2009, which illustrate a variety of planting and maintenance methods performed by several different organizations. In the present study, a sample of planting sites was chosen from the records, representing the two major site types and a selection of the major planting and maintenance procedures. Mortality rates were determined for each site and compared with other planting sites. This study has led to the identification of factors that affected the early survival rate of newly planted trees in the subject sites. More importantly, it has motivated an examination of the methodology for a quantitative assessment of tree mortality rate. As a topic for further study beyond the scope of this thesis, methods are currently being developed to perform this study on a wider scale. This study is relevant to Mediterranean forestry because the methodology presented here can be adapted to analyze urban forest plantings in Mediterranean cities.