If you own property with trees you will most likely have to hire an Arborist at some point to have a tree evaluated. All Arborists are not qualified for all types of tree assessment, though. An Arborist may only be qualified for assessing tree limb stability and pruning or only disease diagnosis and treatment. When looking to have a tree evaluated, make sure the Arborist is qualified for the task.
Arborists are rated through the AQF, or Australian Qualifications Framework, according to their level of training and knowledge. An Arborist that has attained an AQF Level 3 has completed the minimum requirements in theoretical and practical tree assessment and care. A Level 5 Arborist has more extensive training. He or she is capable of preparing official reports in addition to assessing a tree’s condition and providing the care required.
Obvious signs of disease to look for when determining which type of Arborist to hire are fungal growths, cankers, small holes in the bark and frass as well as dead or dying leaves and “flagging.” Fungal growths are generally fairly obvious when the tree has been infected with bracket or shelf fungi. The growths are commonly light in color, fairly flat and stick out from the bark like shelves. They often form on the trunk of the tree and indicate that the wood beneath is rotting. Cankers are sometimes not as obvious. They can be small patches of bark that are slightly discolored or they may be deep, dark and oozing sap. A smattering of small shot holes in the bark with or without frass, a sawdust-type substance, are a clear indicator that the tree has been attacked by bark beetles. The appearance of holes indicates the beetles have done their damage and gone. “Flagging,” when the leaves at the tips of a tree’s branches are dying, is another indication of cankers or bark beetle activity. All of these symptoms warrant evaluation of a tree by an Arborist who specializes in or is qualified for tree disease evaluation and treatment.
A branch that looks weak, has dying leaves or is obviously dead is not necessarily a sign of disease. Check it for signs of disease and, if there does not seem to be any disease or bark beetle activity, an Arborist who is qualified for pruning should be able to handle the job. Tree limbs are often simply damaged by high winds and strong storms. This is especially common in trees that grow quickly. Fast-growing trees will provide shade in a few years but usually have weak wood. They should be evaluated regularly to reduce the possibility of falling branches.