By Mark Chisholm
Trees are wonderful resources that provide us with immeasurable benefits. However, these living marvels can also pose a looming threat to our personal safety and/or property, not to mention liability risks. Help your clients address potential tree hazards. Cumulative afflictions such as insects, disease, nature and human contact may produce hazards and defects in the health and structure of our towering landscapes. Being able to identify tree hazards and choosing a proper course of action can make these problems manageable.
Dead trees and sections
One of the most common situations encountered is a dead tree or tree section. These are some of the easiest risks to recognize since they tend to stand out from the live trees due to a loss of foliage and peeling bark. The only course of action to apply is removal of the tree or dead section. Dead wood fiber is unpredictable. Lightning-damaged trees should also be approached with extreme caution.
Another troubling force for trees is that of severe weather patterns. Many people are aware of the danger of standing under a tree during high winds or lightning storms, but how many forget to evaluate the skyline when standing or walking under trees after a storm has ended? When trees become damaged by such weather conditions, broken branches, tops and even whole trees often remain lodged in neighboring canopies. These hazards can fall free even on a calm summer’s day when a picnic is playing out below.
Hollows and cavities
Hollows and cavities reduce the structural integrity of trees as well. While not every hole is a high risk, different species of trees are more dangerous than others when decay is present. So proper tree identification is crucial in assessing threats from hollows and cavities. The type of hollow and how it is positioned in relation to a cross section of the trunk can also help determine the level of risk involved.
Growth patterns in certain tree types can become hazardous under certain conditions. One example of this is co-dominant trunks. Competing trunks of similar size can develop “included bark” that will eventually fall. In certain situations, installing either a static or dynamic cabling system can make the tree sturdier.
Insects and disease
Insects and disease can also contribute to a tree’s demise. Although extensive training may be necessary to identify the disease or insect, recognizing there is a problem may not. Certain diseases cause rot that is concealed in the tree’s interior but may display its presence by the growth of fruiting bodies and fungus. If you see mushrooms or fungus-like growths along a tree’s trunk, a situation may be present. Mushrooms around the base of a tree or growing from the root system may also mean that a rot is developing.
A variety of factors are required to determine tree hazard risk. First, assess the tree type and environmental condition. Second, examine the level of risk the hazard poses. High-traffic areas such as playgrounds, recreational areas, and home or parking areas pose the greatest threat and may require evaluation by a professional arborist who is trained in tree risk assessment.
Remember, the first step in prevention is identifying a potential threat. Help your clients enjoy their trees, by keeping your head up!
Mark Chisholm is a two-time International Tree Climbing Champion and is certified by the state of New Jersey and the International Society of Arboriculture (ISA). Chisholm conducts educational seminars nationwide on behalf of Stihl Inc. For more information visit www.treebuzz.com.