Tree Tech Consulting    The Knothole  Hop To Forum Categories  The Underground World    Remediation of severe Root Damage

Closed Topic Closed
Remediation of severe Root Damage
<Scott Cullen>
In another thread JPS asked: "Speaking of discussion, What remidiattion, if any are you dooing to the trenched tree you spoke of. I know you said that no guying is being done.
Maybe we should take this to one of the other forums?"

I think "roots" is the appropriate forum. The guying is on hold, but may be undertaken later.

For the audience who were not in Savannah the tree is Quercus alba 45"dbh, 90 feet high, 90 foot branch radius. Suffered 89% root loss from trenching (assuming roots to 24" deep and 100% = unpaved area withinn dripline).

The team was careful not to characterize any actions as "remediation." The damage cannot be fixed. Th cut roots were 12" in diameter. Efforts to help the tree try to recover included the following:

1. Mulching to dripline over the undamaged area.
2. Monitor soil moisture with tensiometers and irrigate when indicated. (For the CA folks we have not problem irrigating our oaks).
3. Trunk injections (Alamo I think) to control two lined chesnut borer and anthracnose.
4. Soil treatment with bio-stimulant and/or michorrhizae.

(The plant health care part of the team specced the treatments which is why I'm not sure of exact materials used).

The team's opinion is that there is a high probablity of mortality. The client instructed that if that means a slight likliehood of survival, then let nature take its cousre, let it die in its own time. So the program is intended to take care of some obvious things that might help the tree over some critical hurdles. There is no intention to keep the tree on long term life support.
Report This Post
<James Causton>
Reply to post by Scott Cullen, on October 19, 2001 at 20:00:53:

89% loss??? Whoaaa!!! that is very serious. In fact so serious it is hard to believe that anyone would even give the tree a chance.
Who was the "highly trained technician" responsible for that?? Whoever it was needs sterilizing, this is not a trait we need in the gene pool!!!
I think that "high probability of mortality" equates exactly with "slight probability of survival". So what criteria is being used in the process of determining what should be done or attempted?, is it time, a fixed budget or what? How long after the damage was done did anyone qualified with trees get on site?. Would application of bio-stimulants really be the best choice, which ones have been discussed/recommended?
This situation is really interesting to me as I am dealing with a very large old tree which also suffered massive root loss, though probably only 66% over the last 10 yrs.

Report This Post
Reply to post by James Causton, on October 19, 2001 at 20:00:53:

I understand your initial response.

The damage was done in February (full Winter dormancy in NY) and the team was on site within days.

We'll keep names out of it. The plant health care team included one very experienced and very conservative arborist (originally trained as a forester) and one Ph.D. forest pathologist who has practiced in tree care for years. I was the interpreter.

Your observation that that "high probability of mortality" equates exactly with "slight probability of survival" is exactly correct and exactly what was clearly and explicity communicated to the client... in writing, in two public hearings and in executive meetings.

To be more complete "high probability of mortality in the near term, say 3-5 years; even if it survives high probability it will decline beyond that and become so unattractive in the mid term, say 5-10 years, you won't want to look at it; and even if it survives beyond, high probability it will develop basal decay and become unstable in the long term, say 10-20 years."

The team did NOT recommend what to do about the tree (in terms of plant health and survivability... stability was treated separately). This was not an oversight, it was intentional and fully understood by the owner. What to do and what chances to take were ownership decisions. The owner was fully cogniscent of the risks and the minimal chance of survival and decided that the tree would not be removed pre-emptively, that nature would take it's course and if the unexpected happened, fine.

The criteria? The tree is in an historic landscape district, surrounded by historic properties, adjacent to a perpetual conservation easement and is a foreground element in a designated viewshed. It has aesthetic qualities that make it publically notable and after the damage there were public comments about that specific tree but not others. The tree also became a symbol.

There is not a firm budget, but everyone is clear that things will not be done simply to spend money. After two full growing seasons, there is dieback but not so much that removal has become the only clear option. Treatments and management will not continue beyond a point that it becomes clear they are not likely to help. That point has not been reached. Additional dieback (lack of leafout) next growing season may or may not make things clear.

In terms of ultimate recovery of damages, the owner has a legal obligation to mitigate damages and that is being done in a responsible fashion

There remains a possibility that there are functional roots below the level of damage and the deeper test pits or under paved areas even though the historical record and test pits suggest not. That would change the %loss figure. And while not frequent, there are some really surprising cases of trees surviving catastrophic damage.

I am not a PHC specialist so I can't tell you exactly what material was applied. I can tell you that the team talked to a much wider circle of nationally regarded experts and researchers and decided what they did was not liable to cause more problems.

I can tell you this is both an unusual tree and an unusual case. It is not held out as a typical example of managing severe damage. It has provided an example of how to manage unusual cases and that's why the structural side of the case was on the program in Savannah.

I want to reinforce that decisions about spending money and whether a tree stays or goes are OWNERSHIP decisions. The arborist's job is to give the owner as accurate a technical picture as possible. The owner may want recommendations or alternatives from the arborist, but the decisions remain the owner's.

This was also a textbook case of the team approach. The owner was fully in favor of that. The team members were explicity instructed that they could share data and researched material but should reach their conculsions independently from each other. The experts were selected in part because there would be no egos... these are experts who have no problem seeking outside input. Arborists should be comfortable with that approach... there is no need to appear to have definitive answers to every question, though I think some try to. Teams are especially useful in unusual, complex or difficult cases.
Report This Post
<Adrian Walters>
Reply to post by Scott Cullen, on October 19, 2001 at 20:00:53:

Are there any tree stability issues here, i.e. health and safety, risk of falling etc. If so have these been addressed. I would like to add the opinion that the tree has a 100 % chance of dying, and that the proposed actions are a waste of money. Whoever the client who is, they seem to be being led up the garden path as regards footing the bill.
Report This Post
Reply to post by Adrian Walters, on October 19, 2001 at 20:00:53:

I did not see you recent query until today, sorry to respond so slowly.

To answer your first question, yes there are both tree health and tree stability issues and both are being addressed.

The Spring 2002 update on tree health is that the tree has leafed out within a few % of the crown that survived into Fall 2001, i.e. most of what was grren and the end of last Summer set buds that survived the Winter. Foliage size, quality and color are good and actually ahead of other undamaged white oaks in the area. Yes we are quite surprised about that. Tensiometers re-installed and borer treatment scheduled. Team re-evaluation scheduled for mi-late June when leaf expansion should be complete.

Stability is the principal concern. It is less a concern than in the initial evaluations becasue it did not budge in 60mph+ winds in leaf with an unreduced crown in 2000 (when it was actually scheduled for removal). Reference marks were installed for plumb and are checked frequently. We check frequently for evidence of root plate movement. We have taken a probability of failure approach which must consider time. The likliehood of a wind significantly greater than the 60mph already experienced in a short time frame is rather small. If it appears the tree will actually surprise everyone and survive into the mid or even long term then that probabilty goes back up and we will have to re-visit guying with the structural engineer and lawyers who are already on the team.

As to your observation, yes. Every tree has a 100% chance of dying. Nobody is being led up or down any garden path. The client has been fully informed about every aspect of the tree's condition and prognosis and it was the client's decision to let nature take its course. The client specifically approves any expenditure before it is scheduled. The client has decided this is not wasteful... it is their money.

A lot of background is provided in my 10/01 response to James which you'll find in this thread.
Report This Post
<Jesse Milton>
Scott, I would love to hear an update on the progress of the subject White oak.
Report This Post
  Powered by Social Strata  

Closed Topic Closed

Tree Tech Consulting    The Knothole  Hop To Forum Categories  The Underground World    Remediation of severe Root Damage

© 1997-2003 Tree Tech Consulting. All messages are the property of the original author.