Construction Damage

Construction damage is probably the number one cause of tree death in urban
settings. What is construction damage? Any mechanical injury or change in the trees
environment due to construction. Construction can be anything from installing a new
irrigation system to constructing a new building. Anyone who has watched all their prized
trees die within a few years following construction knows how frustrating this problem is.
The sad thing is most tree deaths could be avoided with one simple call to an arborist when
tree stress appears or, ideally, prior to the start of construction.

Tree stress from construction damage can manifest in as little as a few months or
take several years to show up depending on the tree species and health prior to construction.
Symptoms to look for are leaf drop, thinning crowns, dwarfed leaves, yellowing leaves or
insect and/or disease infestation.

Damage can come in the form of sideswiped trunks, broken limbs or improper cuts
made by construction workers, unaware of proper pruning techniques. But the most
traumatic damage is done to root zones. Grade changes and soil compaction, which are
always products of construction, leave soils that were once rich in nutrients and chemistry,
lifeless. As little as four inches of soil placed on top of a root zone can kill some species of
trees: especially if the soil is placed directly against the trunk. Soil compaction, caused by
heavy machinery and even high traffic walking, squeezes the air and water out of soil. Soil
organisms and tree roots are suffocated, and these dismal conditions make it very difficult for
the penetration of new root growth and soil organisms. It is impossible to eliminate these
factors from a construction site, however, measures can be taken to decrease the affects,
and soil amendments can be added to put life back into the soil.

By Keith Brown

Certified Arborist