Measuring tree response to increasing root removal intensities

2016 | Justin Morgenroth, PhD, University of Canterbury, New Zealand and Co-Investigator Andrew Koeser, PhD, University of Florida

Conflicts often exist between trees in the urban forest and buildings, roads and footpaths, and underground utilities. Such conflicts frequently result in the damage or complete removal of tree roots. While avoiding root damage is the most effective strategy for preserving tree health, site constraints can put trees in close proximity with development activities. Currently, practicing arborists rely on industry best practice documents informed by relatively few studies when deciding if a given tree can be retained or should be removed during site development. These documents feature largely anecdotal root diameter thresholds for identifying acceptable root removal limits, which fail to account for the size of the root(s) relative to the size of the tree, and also the total number of roots to be removed. Current best management practices (BMPs) also fail to account for the cumulative effects of repeated root injury resulting from site development and eventual redevelopment or repair. This study will monitor physiological and tree growth responses to various root removal treatments to determine ‘acceptable’ limits, and establish evidence-based root removal guidelines.