Analyzing 54" dbh white oak

[Gopher]

Attached are a few of the photos I took of a 54" dbh white oak in a community near my home. The homeowner was given an opportunity to obtain a second opinion on the tree, as the city has it marked for removal.

The tree could be 250 years old, possibly more.

It has seven cables in it, having been in the tree for many years. Cement was added many years ago as well, with most of it removed by yours truly today, as it was very loose at the branch union.

The base is approximately 7 feet across, and the hollow portion starts at about 5 to 6 feet in height (although I do not know if it has been filled). At the largest opening, the cavity is 38 inches wide at the widest point; the tree is 48 inches wide at the same point (as close as I could measure).

At a point about 6.5 feet above the ground, I was able to put my Biltmore stick into the trunk to 36 inches.

The tree, as you can see from the pictures, has good vigor, and decent wound tissue.

It would be easy to cover ones butt and state that this tree exceeds threshholds for possible failure, and recommend removal (which I may do). However, I talked to the city engineer and director of public works today, and I have bought the owner (it is located on private and public property) and the tree some more time.

The tree is about 75 feet tall, with an average canopy spread of 65 feet.

There definitely would need to be more cabling, but at what point is there not enough integrity left?

I also through out the idea of tearing out the sidewalk from the drive way to the corner, and making the street "No parking" from the drive to the corner (which is the distance of about two parking spots, and it is a quiet street).

What do you all think?

 

[clearance]

All good things eventually come to an end, it has brought pleasure to many, for many years. Now you have legitimate reason to believe it poses a threat to human life, so cut it down. Remember, humans come first, not a popular view among some on this site, but they do.

 

[Gopher]

human life

Yes, Clearance, I have always put a person ahead of a tree, and we manage people not trees. I hope to have other comments before the day is out, and I thank you for your candor.

 

[John Paul Sanborn]

This is one of those things where there is an elevated risk of failure in a high target area.

The no parking would reduce target values some, bit one cannot remove the pedestrian ROW. The target area for this tree is across the street anyways.

The major risk here would be leaf-on snow loading combined with wind, which happens every 10 years or so in your area. (maybe more often with global warming?)

Any report would have to include the high risk which the city has already spoken of (we complain about them leaving all those crappy silvermaples...).

IMO the risk of failure is not all that high unless we could find an area where there is a considerable loss of cylinder thickness (what's the formal phrasing?)

BUT

The target value with the street and surrounding houses, combined with the known defect could put the owners in a very tight spot if failure does occur. With insurers backing out of policy claims more often, it would be very likely that if they tried to keep the tree they could be left solely liable for any loss incurred.

Would you write a rider on a policy to keep the tree if you were still selling insurance?

I do not feel that a report should just be "remove it" but should allow the owner to make that decision from an informed basis.

My report would state that the tree is not an immediate hazard, but there is an elevated risk of failure that could catastrophically impact the owners financially.

My reasoning for leaning toward removal is not the somewhat higher risk of failure, but the very high value put to the target zone.

 

[Sprig]

I am inclined to agree with clearance though I am not an arborist. This old tree is being cabled, has a potentially funky core, is beside the road and it is not just a matter of it failing with a car parked underneath it but anyone driving/walking by, how ever high the odds against being smunched the possibility still exists. It is an old beauty, shows good vigor and obviously wants to live but it is not in a field away from things. It is big and I am sure carries great weight in those branches and the size would make me hesitant to keep it. I think the biggest concern that comes to my mind when viewing the pictures is the cavity running down its center, I mean, how much cabling will a tree such as this take before it is too much and what are the possibilities of this tying it together actually weakening upper structure? Could it be monitored closely for cracks and upper structure dying and there-by giving it some extra time? I don't have the definitive answers you seek this is just my humble opinion based on what I see and based on my own feelings about it, I could be miles off base but personally I wouldn't want it in my immediate vicinity as it stands. Thanks for bearing with me.

 

[John Paul Sanborn]

how ever high the odds against being smunched the possibility still exists.

This is why in evaluating we need to wegh the target value.

Hazard is risk of failure + target.

If it is in a park off the main path but has a picnic table under it, the target value is high. If we move the table, we lower the target value. Some argue that we can reduce this value further by not mowing under it. Which brings us to your "in a field" scenario.

I don't have the definitive answers you seek this is just my humble opinion based on what I see and based on my own feelings about it

Which is why I carp about consultants just giving a "remove it" responce. Your risk tolerance may be way lower then the clients.

Sometimes this is the only professional opinion that can be given, but most often we need to allow the client to be the primary decision maker.

On an aside, it is not allways a good thing to bring in the insurer. I've seen occasions where they say "remove it, now, or we cancle the policy".

 

[clearance]

This is what really bothers me about risk "management", others deciding to risk other peoples lives without their knowledge, over a tree, in this case. Basically it is rolling the dice, in a dice game of life and death. When trees fail and kill people, which they do, from time to time, what do you think of arborists who saw those trees and let them live? How do they feel? So the picnic table under the tree is a high risk, move the table the risk goes down, still a risk. Wrong place, wrong time, perhaps for some poor soul. In the forests of BC it is illegal to leave snags when you are logging that could endanger the fallers or rigging crew. It is however common practice to leave snags in parks, beside trails, playgrounds, playing fields. Makes a lot of sense, roll the dice, by all means, with other peoples lives of course.

 

[Sprig]

Thankyou Paul for your input and insight, and re-enforcing my gut reaction to this scenario (and not chewing my azz out for noob opinions). I too feel that the homeowner has a responsibility to weigh the possibilities and take it from there, how much risk is too much? What are your feelings on this particular tree given the information here? Sorry, an edit, you did that already, my bad for not paying attention, I am assuming you would recommend removal then? Just my curious learning curve.

 

[Dadatwins]

Hard to tell from a chair looking at pics, but like JPS said there is potential target, regardless of no parking, risk does exist. If the tree was in a park away from anyone or anything it could probably stay another 100 years, but on a residential street with the potential for failure the city and homeowner have to consider the possiblity of the tree failure and possible lawsuit. I read somewhere that a cable in a tree is now an admission of fault in a tree and if a cabled tree fails the owner could be sued based on the fault that was 'recognized' and 'attempted to repair' . It is a shame that we must live in such a lawsuit happy society. Enough cables and bracing could probably be installed in the tree and I remember seeing some steel wraps that were used in Russia? by grigory? pics posted here a few years ago, but the potential hazard would still exist due to the location. I agree all the owners of the tree have to be advised of the potential risk and make the decision. Obvious measurements of the remaining wood, close inspection of the limbs and cavity and weight measurments of the potential limbs and the ability of cabling to hold such weight all must be considered.

 

[Gopher]

Information to allow a decision to be made

I am planning on attending the next City Council meeting, as the homeowner is on the Council. The homeowner/half tree owner knows that the trees days are numbered, but also realized that she wanted to gather necessary information to allow herself as both a landowner and a Council member to make an educated decision and vote.

A good process is happening. Trees will fail. The system fails when there is a lack of communication, and sound judgement, knowledge and understanding of principles ignored.

Everyone benefits in this scenerio. The outcome will be based on unbiased, independent professionals using our arborcultural experience, all of us!

Based on my measurements and the condition at the junction of the three major laterals or stems, and due to the fact that unless the road was closed, and the sidewalk closed, and the home and yard vacated, there is more than the average risk involved by leaving the tree stand.

It was a pleasure to climb it; though the center stem is probably the best of the three, there isn't much sound wood beneath this one either.

Keep the bantor coming. Keep the process alive, and I sincerely thank all of you for your thoughts and experiences.

 

[maxburton]

I was all set to write a research paper in college about cabling, but then I found out that there is no data out there about the reliability of cables. Installing cables is not a science, because the information that would make that possible has never been collected. Therefore, the only thing you can be sure a cable will do is control failure, not prevent it. I wouldn't trust cables to prevent a disaster in this case. I would remove that tree and plant a replacement for everyone to enjoy.

 

[Gopher]

We have a winner...

Yes, a repelacement tree would be a good idea, one a few feet farther from the walk. Well put Maxburton.

 

[clearance]

I am planning on attending the next City Council meeting, as the homeowner is on the Council. The homeowner/half tree owner knows that the trees days are numbered, but also realized that she wanted to gather necessary information to allow herself as both a landowner and a Council member to make an educated decision and vote.

Everyone benefits in this scenerio. The outcome will be based on unbiased, independent professionals using our arborcultural experience, all of us!

The lady will have to excuse herself from speaking or voting on this matter at the council meeting as it is a obviuos conflict of interest. There is no such thing as neutral, objective opinions in this field, none, I am the first to admit it.

 

[Sprig]

If/when it get taken down I'd have some of the local furniture builders look at it, assess the potential lumber in it and have it bucked accordingly, I am willing to bet they'd be drooling. Gopher, I am glad there seems to be some sensible dissertation on the matter. Good to see man.

 

[treeseer]

"It would be easy to cover ones butt and state that this tree exceeds threshholds for possible failure,"

I'm with Dada; more assessment may be in order. Documenting 36" cavity in a 52" tree is a start, not the finish.

Good on you Dave to get the process of tree risk management open to the public.

We roll the dice every time we get out of bed, or fly in a plane, or...

 

[darkstar]

danger

Sure the tree is a danger but you'd be more likely to be hit by a car at that location , than the tree actually falling on you .Let the tree come down when nature brings her down.

 

[spacemule]

Let the tree come down when nature brings her down.

Why do we need arborists at all then? After all, nature will take care of the trees.

 

[John Paul Sanborn]

Sure the tree is a danger but you'd be more likely to be hit by a car at that location , than the tree actually falling on you .Let the tree come down when nature brings her down.

This is where I come from with risk tolerance.

The city offers to take it down, this absolves them of some liability though a lawyer could argue they should have condemned it.

Maybe you as a homeowner and your neighbors in the target zone admire the tree and feel you can live with the risk.

if it falls on someone, then you will be held liable for not correcting the defect, which in this case is removing the tree.

As i stated above, it's likely that insurers will walk a way from it in the case of catastrophic failure, and may require the removal if they find out about it.

By leaving the desicion to the client, Dave sheds much of the liability if it stays, but any one can be sued. Which is why some companies will say "remive it" if they see only any defect.

 

[Gopher]

Risk assessment

It is for this reason that I like to be involved if and when an issue goes to court. It is then where we HAVE to be listened to, whether it be before a judge or judge and jury.

It is preferred to have that credibility at the community level prior to that point, but in either case, the process is then working.

My thought on this centuries-old oak is to meet there with many of the parties involved and I will run the meeting from the canopy. They can have my report with pictures in hand, and I can elaborate from the tree. Then, if some alternatives are brought forth, measurements and scenerios and be handled on-site.

Have a great Memorial weekend everyone.

 

[treeseer]

My thought on this centuries-old oak is to meet there with many of the parties involved and I will run the meeting from the canopy. They can have my report with pictures in hand, and I can elaborate from the tree. Then, if some alternatives are brought forth, measurements and scenerios and be handled on-site.

Excellent solution. I'd like to do this with every borderline tree. Since the owner is a town councillor, they will come.