Trees and Construction

Protecting Trees in Construction Zones

If you are involved in a construction project, here are some tips to help avoid tree damage during construction, whether they are specimen trees of historical and cultural significance, or just your favorite trees.

• A physical barrier nothing less than a chain-linked fence should be erected at a minimum of the dripline around the tree. (The dripline is the area directly located under the outer circumference of the tree branches.) Orange snow fence is not recommended, as it may not be enough of a barrier to keep construction away from the tree. The further outside of the dripline the fence is placed, the better, as the fine feeder roots of the tree can extend 2 to 3 times the height of the tree from the trunk. Nothing should be stored or staged inside the enclosure (see top right photo.)

• Vehicles and construction equipment should be kept as far away as possible from the fenced-off area, to minimize the stress and compaction to the fine feeder roots that extend out from the tree. Construction equipment should not be allowed to drive all the way around next to the perimeter of the dripline exclusion barrier, as it would likely result in soil compaction.

• When working with contractors it is strongly encouraged to include language in your contracts that would penalize them for physical damage to trees, changing grading within the dripline of the tree, and soil compaction, and would require “clean” cuts to roots (see middle photo.) Additionally, there is no substitute for educating the men and women doing the work and their supervisors about the importance of preserving a healthy tree and their important role in minimizing stress to it.

• Other than large physical wounds that may take place during construction, such as the ones seen in the bottom left photo, the effects of construction damage often take 5 to 10 years to appear. Decline in the health of trees is not always easily recognizable. Therefore, the more that is done to protect and maximize the health of trees during a stressful procedure, the better it will be able to adapt to the changes and thrive into the future.