The situation: 15 inch DBH Live Oak in College Station Texas was hit by a car during a traffic accident. The tree lost bark, phloem, and cambium around 60 percent of the cicumference of the tree from the ground up approximately 2.5 feet. The tree was elevated approximately six inches from its original placement in the soil. Obviously there are many aspects of the tree that will be affected by this damage. The owner claims that the insurance will only relace the tree if it dies, but is willing to pay damages to the tree. The tree is estimated to have a Trunk Formula value of $10,300.00, and a cost of replacement value of approximately $22,000.00 which includeds the removal of the tree, replacement and maintenance for three years to get the tree established.

The question: The property owner wants to settle this matter with the insurance company by accepting a reasonable amount for the value of the damage caused by the accident. Is it possible to assess the value of the damages done to the tree, and if so how might I begin to attack this problem? I can not imagine that it is possible to restore this tree to its condition prior to the accident, and the effects of the damage may not be evident for many years.

Your thoughts are greatly appreciated.

Jeff, the first issue is the % of loss. You seem to indicate that the tree will not die right away. But in your opinion, or any group of experts' opinions is the tree stable structurally? Is it now a hazard? If yes, the the loss is 100% even if it won't die immediately.

In any case you need to estimate the value of the tree before the damage. If it is 100% loss than the value before = loss. If loss is less than 100% than you need to estimate value after the damage. The loss is the difference.

Actually in either case the los should include cost of the appraisal and the cost of removal and cleanup. 100% of the latter if 100% loss. Some portion of it from 0% to 100% depending on how far out in the future you think removal is. IF there is a very good chance of survival, then 0%. If the tree is likely to decline and die or become hazardous from decay say in 10 years then the discouted cost of removal in 10 years. There are probably lots of instructors at A&M who can help you understand discounting.

I hope that helps.

Scott

Hello Jeff:

I am a Forestry Technician in Regina,Saskatchwan, Canada. I am wondering if you were able to find any solution to your posting regarding this issue.

Similarly, I am trying to determine values for damages to trees caused by vehicular accidents. These are generally, damage to the trunk of the tree where large amounts of bark, phloem and cambium layers were lost from an American Elm-41cm diam trunk (16") The damaged area was at the base of the trunk and measured approx 140cm * 50cm (20"*56").

I have determine the value of the tree prior to the accident, however, it is difficult to determine a diminutive value for the loss in order to claim compensation from the insurance people. Where do you make the measurement at to determine the percentage of loss?

If you have had any feedback or offered solutions, I would appreciate hearing back from you. Thanks Ray

A partial loss is dependent on the primary factors that affect the tree’s benefits to the landscape. It might be measured as a loss of crown volume or perhaps as a reduction of SULE (Safe Useful Life Expectancy).

We know a relatively small wound on a trunk will probably compartmentalize (depending on species, of course), and not result in serious long term decay. A much larger wound will likely result in severe decay of the trunk. We can also estimate the time the decay will take to weaken the tree. Now comes the professional judgement part- will the tree outgrow the decay or will the decay outpace the tree and result in a hazardous condition? If the latter, how long until the tree will probably be unsafe or so unsightly that its removal is necessary. Compare this to a projection of the life of that tree had it not been injured at that time.

This assessment must take into account any previous injuries. For example, if the tree had previously been struck, and was already doomed to a shortened life, the owner is probably not entitled to a large payout. If the tree was in bad shape and had to be removed soon anyway, the difference in SULE is quite small.

Once these factors are considered, along with other pertinent facts, the expert appraiser can assign a partial loss. As Scott pointed out, you can do the appraisal twice, once for the tree before injury and once after injury. The real difference is the condition factor. Or you can assign a percentage of loss, apply that percentage to the ’before’ vale, and derive the loss amount. Keep in mind that if you start with a 70% condition, a 50% loss means the tree now has a 35% condition rating, or half of the original assigned condition rating.

I hope this helps.