Daytona Beach City Hall oaks
Excerpted from the article, Cabling and Consulting: Connections for Safer City Trees, by Guy Meilleur from The Australian Arbor Age, December, 2008, pp. 54-58.
In 1876, the city of Daytona Beach, Florida was founded in a forest of live oak, Quercus virginiana, which covered much of the southeast coastal region of the United States. Most of that forest was removed to make room for the growing city. Historian Harold Cardwell said about one live oak, “This city has had many changes over time, but the tree has always been there”.
In 1975 Cardwell, then a landscape architect,appraised the tree for Dr. Robert Thoburn, a dentist who owned the property on which the tree grows. Before selling his property to enable an expansion to the city hall building, Dr. Thoburn wanted to ensure its preservation by including the value of the historic tree, which Mr. Cardwell said was in pristine shape. At the time, Mr. Cardwell estimated the tree was 240 years old, using the rough guide for live oak of one year per inch circumference at the base. He appraised it at $75,000 based on a replacement cost formula, using the amount that Disney World spent to move the Liberty Oak and establish it at its Liberty Square location. Cardwell was not surprised to learn that arborists today are using a similar replacement cost method to appraise large trees, as described in the current 9th edition of the Guide for Plant Appraisal. He estimates that the tree’s value today could be $150,000, but its historical value is “priceless”. He noted that the city fathers routed the two main roads around the tree, so when these roads were later widened the tree lost critical roots.
On July 7, 2008 a branch fell from a nearby live oak onto the walkway leading to city hall, so the city paid for a risk assessment from an ISA Certified Arborist on that tree and the Thoburn Oak. (see the second photo below.) In a one-page letter dated July 18, the arborist proposed removing both trees. He said that they posed a danger to the motorists and pedestrians who pass under them each day, but gave few details. Tree risk formulas typically rate the severity of the defect, the size of the defective part, and the “target rating”, or use of the area under the tree. Next, management options to lessen or “abate” the risk are considered, before recommendations are made.
“Development of abatement options should be as systematic as development of the ratings… cable/bracing and/or reduction of end weight may be required…”, according to A Photographic Guide to the Evaluation of Hazard Trees. This arborist later said that “Target rating is the most important factor for me. If there’s a lot of use under the tree it’s dangerous, no matter what you do.”
The city’s Tree Advisory Board rejected this defensive report, and decided to get a second opinion before the city decided the fate of two of the city’s most visible historic trees. The board’s chair agreed, saying “I’m not comfortable recommending anything until I know more about these trees. It feels like these trees have a cold and we’re proposing to euthanize them.” However, another member said he’s observed them for the last 40 years and “these trees have lost the capacity to grow. I don’t see spending more for something that’s so obvious.” He predicted that in the next year “there won’t be a leaf left,” on the trees.
The board compromised, hiring another ISA Certified Arborist to get a second opinion at a lesser cost. In his letter accepting the assignment, this arborist agreed to assess the tree, give recommendations, and provide an estimate for doing the work. For a risk assessment or any report to be reliable, it should be completely independent, unrelated to estimating the sale of other services. Despite the apparent conflict of interest from blending an estimate into the assessment, the report went forward. Its recommendation was to remove the first tree and to prune the Thoburn Oak along with injecting fertilizer. Not surprisingly, that company uses the same proprietary product and method that was recommended. The work was scheduled for the following Saturday.
BCMA/RCA Chuck Lippi and five other consulting arborists from around the region (including the author of these two articles, Guy Meilleur) were concerned about this landmark tree and the opinions rendered thus far by the two arborists hired by the city. So Lippi, Meilleur and three other consulting arborists assessed it at no cost to the city. A summary of their report published in another arboriculture trade magazine follows below.