As Fall continues on and cooler weather approaches, trees will soon be barren of leaves. When this happens, the ISA Certified Arborists at Oak Bros Tree Care & Removal won’t be able to make complete decisions on tree health but they will be able to better assess tree structure. Tree structure has a direct correlation with the likelihood of tree and/or tree part failure. As our weather patterns shift, our area has been experiencing more violent and unpredictable wind and ice events. As these events occur, they cause a tree to be “loaded” more than they’re used to in their normal growing environment. A load is any force a tree experiences such as gravity, wind, ice, and rain. As a result of a tree’s growing environment and/or species it may be predisposed to certain defects which commonly contribute to failure. Some trees naturally have narrow and upright growth habits which may result in tight, V-shaped, branch unions that eventually lead to bark inclusions. Bark inclusions occur when bark becomes embedded in a branch union between a branch and trunk or between codominant stems, which causes a weakness in a union. These weak unions are a common contributor to failure.
Cross section of bark inclusion on hickory. Notice the individual stems (arrows) on the left and right of the bark inclusion (circle).
In bark inclusions, affected branches are able to move more than normally formed branch unions. As a result, when a tree with a bark inclusion experiences more weight from ice, snow, and/or wind it has a higher likelihood of failure. In extreme cases, branches with bark inclusions fail with no added weight. In the photo below you can see tree failure as a result of bark inclusion. Notice the lack of attachment (dark area).
Codominant stems grew too tightly at a young age and developed bark inclusion, ultimately resulting in failure.
Tree structure defects can be managed through structure pruning, support system installation, and branch removal. The ISA Certified Arborists at Oak Bros Tree Care & Removal are well-equipped to assess your trees and make sound recommendations so that you can enjoy your investment for years to come. Contact us to schedule a site visit
