Jerry and Anne Brown owned a cottage on a quiet, private lake. Their family had enjoyed this lakeside vacation home for several years. Jerry and Anne, along with their children and grandchildren, gathered there every summer to swim and fish. They’d sit outside on the deck to enjoy their morning coffee. They’d gather on the same deck at dusk to watch the light fade from the lake at the end of a nice day.
In the center of the deck where the family gathered grew an ancient American beech tree. This beech was approximately 140 years old with a trunk diameter of 42 inches. It towered over the second- and third-growth trees in the area, and somehow escaped being cut when the area was originally logged-off.
American beech is one of my favorite trees. The unusually smooth, gray bark, the deep green foliage and the graceful open-branching crowns make them one of the most attractive landscape and forest trees. The beechnuts are also an important food crop for several wildlife species. When a beech grows to this size, it invites even the most timid for a climb. If you’re lucky enough to witness a whole grove of mature beech, they remind you of something out of a storybook. The woods remind me of Sherwood Forest or the Ewok Village, amongst the trees of Endor (for all of you “Star Wars” fans).
Jerry and Anne loved this gigantic beech tree, as did the rest of their family. Also, if it’s not already apparent, I had grown attached to their beech tree as well. You see, I had been caring for it for many years. I first became involved because the beech is hollow. You could literally stick your head through a large hole in the trunk and peer up the cavity column. Over the years, to make the beech as safe as possible, we lightened the crown, cabled a couple of leads and fertilized it.
Mr. Brown was a great client. He called each spring to have us reassess his tree, for he knew full-well what might happen if it failed. But with each passing year, he was becoming increasingly nervous.
As much as everyone loved the beech, it hovered over his family gatherings. The main trunk was obviously hollow, and it was inevitable that one day the tree would fail – it was only a matter of time.
When it did, the results would surely be catastrophic.
When he called that last spring, I could immediately tell from the tone of his voice that something was different.
“Vic,” he said, “we’re getting up in age, and Anne and I have decided to sell the cottage to our son. Before we do, I want your best guess as to how much longer this tree has. If it has to come down, I don’t want to pass that expense on to him. We both know how expensive removing it will be. And I don’t have to tell you what our other concern is.”
Removing his beech tree would indeed be expensive. It’s a tree removal scenario that all tree service companies dread. For one, there was no equipment access to the lakeside of the property. You also couldn’t get a crane close enough to lift the tree over the house. The deck would first have to be removed and every single limb, branch and twig would have to be carefully lowered and all of the material hauled to the street through a narrow gap between his house and the neighbor’s. There was also the whole safety issue of putting a climber in a decidedly hollow tree.
Jerry asked me the two questions that cause every arborist to cringe:
“Is my tree safe?”
“If it’s safe, then when will it become unsafe?”
For such simple, straightforward questions, there’s rarely a simple, straightforward answer.
You can always take the approach that when in doubt, cut it out. That certainly simplifies our jobs. But, Jerry asked for my honest opinion of the tree’s condition, not an excuse to take it down.
I thanked Jerry for trusting such an important assessment to us and that we needed to perform what would one day become the equivalent of a Level III TRAQ assessment.
To determine the structural integrity of his tree, we used a Resistograph Machine to test the trunk in several places. We also did an aerial inspection with a qualified climber. I even called in an outside consultant for a second opinion.
- The tests revealed a main trunk with only 4 to 6 inches of sound wood surrounding a central cavity of roughly 30 inches in diameter.
- The crown was full and healthy.
- The limb attachments were strong.
- The annual growth rates were in the normal range for American beech.
- The root zone appeared to be undisturbed, except for the deck.
- Over the past 10 years, the tree was well maintained.
The Resistograph readings contained the most disturbing findings. A central cavity of 30 inches is significant. The rest of the tree, however, was in excellent condition. The question for us quickly became, “How much central trunk decay can a beech tree sustain before failure?”
To find that threshold, we used Dr. Nelda P. Matheny and Dr. James R. Clark’s wood strength guidelines, as described in their “Evaluation of Hazard Trees in Urban Areas.” The guidelines state that with no other concerns noted – such as lean, splits, low vigor, root zone compromise or trunk defects – and with an understanding that a strong enough storm can cause even the healthiest of trees to fail, and even with the best of tree risk assessments, flaws can still go undetected. Taking all of that into account, according to the guidelines a tree needs a minimum of 1 inch of sound wood to 3 inches of unsound wood to retain a 67 percent potential trunk strength.
Jerry and Anne’s beech tree had a 30-inch diameter trunk cavity. Surrounding the cavity was 8 inches of sound wood. Their tree barely fell within the 1-to-3 threshold ratio. There were, however, other concerns. There was the large hole in the side of the trunk and the tree grew within a deck. The target rating was off the chart as well.
Knowing how much their tree meant to the family, I have never wrestled with a tree risk assessment as much as I did this one. For some reason, I wouldn’t take the easy way out and just say, “Take it down, problem solved.” Several experienced tree care pros I talked with advised as much.
In the end, I decided I would describe our findings objectively and clearly. The decision to remove the tree was rightfully the Browns’ to make. My role was to assess the tree. The conversation went something like this.
“Mr. & Mrs. Brown, we assessed your tree and determined after some lengthy and, at times, loud discussions among our team of arborists … giving due consideration to the arboricultural textual guidelines … and talking with an outside consultant, your tree is on the very borderline of being considered safe, but with no further margin for error.”
They decided to have it removed.
The tree removal job is a story in itself. Due to justifiable concerns for its structural integrity, several of our best tree workers refused to climb the tree – an option we always permit our climbers. So we brought in another tree removal expert to assist us with the operation. He proposed using a complex series of rigging devices utilizing neighboring trees. With his help, the project was completed with no damage to the deck, home or landscape.
To Jerry and Anne’s credit, they chose to do the tree risk assessment and the expensive removal because they didn’t want to pass on to their son the large removal bill, which was up to that point in time the most expensive single-tree removal job we had performed.
It has been my experience that Mr. and Mrs. Brown’s unselfish outlook is not uncommon in people who really care for trees.