A program studying how construction damages trees and what might be done to lessen the damage, was initiated after hundreds of trees with damaged roots from construction toppled following a windstorm in the US. Construction often harms tree roots and the trees eventually fall. A long term study found three per cent of Milwaukee’s trees interact with construction every year. It estimates every tree near infrastructure will see construction challenges in its lifespan and survival rates depend on their tree preservation program.
The study, Long-term effects and development of a tree preservation program on tree condition, survival, and growth, was published in Landscape and Urban Planning.”
Species is important. Sugar maple had the highest mortality. American elm was six times better. Green and white ash were another six times ahead of elm. Silver maple and honey locust were 14 times more likely to survive than elm.
However, across all species tree survival and condition in the full implementation period were similar between trees associated with construction zones and non-impacted control trees. The tree preservation program produces at least six dollars for every dollar invested. The researchers said, “Science and policy, when implemented through urban forestry management activities, can result in a healthier and longer-lived tree population with an economically favorable outcome.”
— Pat Kerr