Climbing spikes are sharpened steel spikes attached to the climber’s leg by leather straps and padded supports. A tree worker should only use them to access trees being removed. When these spikes are used on living trees, it is traumatizing to the tree and creates unnecessary damage.
Each puncture from a climbing spike produces a certain amount of tree tissue death, though this varies from tree to tree. In most cases, isolated wounds will seal, but over time, groupings of spike holes can cause the entire area on the trunk to die back with no chance of recovery. This happens when a tree is repeatedly climbed for pruning while using spikes.
The likelihood of piercing the cambium (living tissue beneath the bark) is high, even with larger trees and thick bark. If soon after the work is performed with spikes there is sap oozing from the wounds, the tree is responding to spike damage. Repeated damage of this type is harmful to the tree.