Trees and Infrastructure Damage
Figure 1, Photo by Bruce Hagen
Tree roots are prone to lift pavement, e.g., sidewalks, patios, driveways, etc. when planted too close to the paved areas. Trees should be planted at least 4 feet away from paved surfaces, even more for larger statured trees. Damaged pavement creates a significant trip and fall hazard for pedestrians. In general, municipalities and landscape architects do not allow adequate space for trees.
Figure 2, Photo by Bruce Hagen
When selecting trees to plant, avoid those with obvious girdling (circling) roots. In this instance, they have totally encircled the tree and will eventually choke off its water supply or lead to root instability. They would have been clearly visible at the time of planting. This tree should never have been bought or sold.
Figure 3, Photo by Bruce Hagen
The roots of trees that lift pavements typically are cut off, and the pavement replaced. The loss of roots, though, reduces the tree’s capacity to absorb water and minerals. Furthermore, it often makes the trees less stable.
Figure 4, Photo by Borneo JC James
Large roots on one side of this tree were severed and the sidewalk replaced in its original position. In doing so, the tree was severely damaged, and its stability was severely compromised. Over time this can lead to toppling. Damage this close to the trunk will also lead to serious decay of the tree's base. Root loss like this also affects health and longevity by reducing water and mineral uptake and supply, and it often leads to branch or premature death.
Figure 5, Photo by Bruce Hagen
Excavation around this tree was too aggressive. Many roots were damaged. If 30% or 40% of roots are removed the tree becomes unstable. Decay grows faster into big root cuts even more than into big limb cuts. Damaging or removing large roots is even more destructive than damaging large limbs.
Figure 6, Photo by Bruce Hagen
The large support roots of this redwood that were lifting the sidewalk, had to be removed to repair the pavement. Consequently, the consulting arborist supervising the work recommended the tree be removed because the root-pruning made the tree unstable.
Figure 7, Photo by Bruce Hagen
Trees should not be planted unless there is adequate space to accommodate them as they grow. In this case, the trees have been planted between parking spaces where they create problems for people trying to pull into or back out of the parking spaces. And because of this the tree are subject to continual injury. Despite the damage and poor growing conditions, they seem to be surviving.
Figure 8, Photo by Bruce Hagen
This poor tree has been repeatedly injured by cars bumping into it. This would not have happened if the planting strip was large enough for the tree and its large support roots and to provide more clearance for car bumpers. Better planning could have prevented this problem in the first place.