"We've got a tree that was scaring people."

Re: \"We\'ve got a tree that was scaring people.\"

"I do not understand. Are you suggesting that TRassessors do not understand pruning? "

I said 'too often', not always. Plus I was speaking generically, not just about those who passed the TRA test. Frequently, suggestions to reduce trees have been met with theoretical and overblown concerns about loss of photosynthesis and 'stress', or suggestions to cable are met with 'but annual inspection is required' so removal is recommended when it need not be.

Are you saying TRA are not practicing arborists?

Many consultants are not involved in practical work. Many hold that as a badge of honor, as if they had risen above a lower professional status. So they're disconnected, to some extent. i'm not judging all the people who took and passed that TRA course, many of whom are practicing, and practical, about pruning and other mitigation options.

"Perhaps you are suggesting that most people with tree risk assessor status are operating at a basic level rather than at a high level of education, knowledge, experience and competence etc.. This I would agree with."

That judgment is based on what? And what does basic and high mean? Some days i see my own level as below basic, clueless.

" It seems that if you can get ISA CA you can quickly become a tree risk assessor for a few exxtra dollars you have a new liscence to charge for things you really are not expert at."

Looking at this as purely a money grab tends to miss the point. no one can 'quickly' get the TRA, with its 85% requirement to pass. I wouldn't dis the folks who have met that challenge. But I am dissing the approach of zeroing in on the natural process of interior decay as if the tree was a dead and rusting pipe, and relying on some very sketchy formulas, while ignoring the life in the tree.
'We know next to nothing about tree biomechanics.' Ed Gilman was right on this, yet assessors *too often* feign certainty where people, all people, are ignorant.
 
Re: \"We\'ve got a tree that was scaring people.\"

[ QUOTE ]


"Perhaps you are suggesting that most people with tree risk assessor status are operating at a basic level rather than at a high level of education, knowledge, experience and competence etc.. This I would agree with."

That judgment is based on what? And what does basic and high mean? Some days i see my own level as below basic, clueless.



[/ QUOTE ]

Basic level is the CA who takes a TRA course or somebody who owns a chainsaw therefore knows a dangerous tree. A high level TRassessor is someone who has attended multiple seminars/workshops, has read a lot of literature, worked with experts in the field, maybe written a paper or two, has knowledge beyond how to find faults, is able to gather information, synthesize it and write a decent report. I think we all know the difference but are not willing to talk about it. Your post gives lots of clues, TRA certification is a two day process in class (plus some studying), a huge difference from many of the consultants who have worked their way through the industry and now write reports but do not climb and prune.
 
Re: \"We\'ve got a tree that was scaring people.\"

well okay i have not taken the course so i cant comment on what that 85%+ score proves, but it does seem like a higher bar than you describe. also the black/white difference is hard to see; we're all gray, what is there to talk about?
 
Re: \"We\'ve got a tree that was scaring people.\"

[ QUOTE ]
Could have just moved the targets.

[/ QUOTE ]

In fact, the main target, a climbing tower used by cadets, was already scheduled to be moved. Here's a review, submitted to the local paper:

GIVE TREES A CHANCE

Carl Absher’s observation (8/20/12 Op-ed), “the assessments of (VT) campus trees offer a great opportunity to expand the education of the students” was right on the money. In fact, they already have! In 2007 I had the pleasure of assisting highly qualified VT professors with their summer course in arboriculture, including comprehensive tree risk assessment. The International Society of Arboriculture (ISA)'s 2011 Best Management Practices (BMP) also follows the comprehensive approach. The ISA BMP considers tree strengths, like concentrations of adaptive growth and sprouting, and mitigation: pruning, support, and monitoring.

Unfortunately, the two companies recently hired by Virginia Tech used a more limited methodology, barely mentioning strengths and mitigation, instead speculating on weaknesses in hollows, burls and seams. A closer look at these three features seems in order:

Hollows: Taproots are prominent in oaks, from germinating acorns to maturity. As buttress roots spread outward, taproots suffocate, die, and decay. Decay naturally creates a hollow as decay moves up the trunk, with little effect on stability. As a test, see how much silverware will balance on a paper napkin ring. If all hollow trees were cut, our landscape would be barren!

Burls are “abnormal swelling of a tree trunk characterized by swirling wood grain and meristematic (capable of cell division and growing) tissue. Wood with swirling grain is typically stronger, as anyone who has split firewood knows. Burls decay in time, as everything does, but they can stay solid for centuries, even millennia in some trees. Yet 60” of burl tissue was discounted in both reports. According to their formula, abnormal = unreliable, so that 60” of vital support in super-normal tissue was considered as strong as air.

Seams are adaptive growth, formed in response to movement and loading. Seams often form in response to bending in the wind. Like new tissue formed after a bone is cracked or broken, wood formed by adaptive growth can be much stronger than normal wood, according to research done by former Hokie Dr. Brian Kane in 2008. The seam on Tree #131 was judged a defect only because it looked different.

A wood coring instrument could have been used to verify of cracks or decay, and the tissue quality in the seam, or in the burl. The wounding might have been justified. Cores could have shown the real strength in that wood, enough to change the calculations, and the results. Instead, VT administration was told that “The seam contributes to the overall defect of the tree…(and) clearly tips the defect into the critical rating.”.


Archaic tree risk assessments zero in on the wood thickness outside the cavity, using a discredited engineering formula, artificially high thresholds, mistaken assumptions, and invalid calculations. Wood thickness was measured by invasive drilling at ground level, despite the risk of introducing decay into healthy tissue. Data from the drilling tests was adjusted downward by 1.5” due to the computer program’s assumption of bark thickness. Anyone looking at the stump today can see this number is exaggerated. Similar evaluations have been skewed by similar automation in similar field forms, recently in Carrboro, NC.



Commonly used formulas are derived from engineering inanimate objects, like pipes. However, “Trees are not pipes”, according to a BMP coauthor. Overall tree risk ratings are calculated by adding numbers from ratings of probability, as shown in a 1994 manual. This method was intended to be used on populations of trees, not individual specimens. ISA BMP: “Ratings are not cardinal numbers, but ordinal numbers. Adding or multiplying ordinal numbers does not yield a mathematically valid result.”



Comprehensive tree risk assessment follows the BMP’s methodology:

Reviewing the site conditions shows a relatively undisturbed rootzone, and the mitigating effect of the nearby trees, which lessens load and risk.

Species failure profile of white oak shows high resistance to decay and failure.

Assessing load would have shown that pruning reduces risk significantly.

Tree risk assessors should look for and assess the significance of response growth.

Advanced assessments such as root collar examination, tissue analysis, or aerial inspection should be done when needed.



As Carl Absher noted, most of this work can be done by students, using comprehensive methods. Trees can adapt to weaknesses and stand for many decades, with a little basic care and attention. Machines used as judges, juries and executioners force good arborists to deliver bad results, instead of giving trees a chance to demonstrate their stability and adaptability. Comprehensive tree risk assessments can save money, and the many contributions trees deliver to our quality of life.
 
Re: \"We\'ve got a tree that was scaring people.\"

This opinion piece needs a little fine tuning


[ QUOTE ]
[ Here's a review, submitted to the local paper:

GIVE TREES A CHANCE


Unfortunately, the two companies recently hired by Virginia Tech used a more limited methodology, barely mentioning strengths and mitigation, instead speculating on weaknesses in hollows, burls and seams. A closer look at these three features seems in order:

Hollows:

*Are they important in TRA or not? the comments latter concerning (t/r) indicates not.*


Cores could have shown the real strength in that wood,

*How does a core show the real strength of the wood? It is not a strength measuring device. It might help to show the thickness of wood but not strength.*

Archaic tree risk assessments zero in on the wood thickness outside the cavity, using a discredited engineering formula, artificially high thresholds, mistaken assumptions, and invalid calculations.

*What discredited engineering formula? Is the suggestion that t/r has no use in TRA or that t/r<.3 needs to be reconsidered. Shell thickness is a commonly used and is intergrated into lots of methods, check out the online calculators that Brudi offers and you will see that you need to measure shel wall thickness and compare to the calcalted value (for safety).*



Commonly used formulas are derived from engineering inanimate objects, like pipes. However, “Trees are not pipes”, according to a BMP coauthor.

*Does this mean that engineering concepts are never applicable to trees?*



ISA BMP: “Ratings are not cardinal numbers, but ordinal numbers. Adding or multiplying ordinal numbers does not yield a mathematically valid result.”


*If that is true either ISA TRA and BMP are at odds or risk assessment calculators as shown in ISA/PNW TRA manual are incorrect (and therefore many other methods)*


Species failure profile of white oak shows high resistance to decay and failure.

*Where these profiles?*

Assessing load would have shown that pruning reduces risk significantly.

*Pruning at the ground would also reduce risk (and this is what two companies suggested)*

*How would load be assessd?*


As Carl Absher noted, most of this work can be done by students, using comprehensive methods. /quote]

*SO why have arborists trained as TRAssessors? Students can do it!!!! If the original companies could not do the job (adequately) how can a bunch of students with limited or no tree experience let alone a knowledge of TRA methodolgies?*


*IF the issue is that the TRA was inadequate how is it to be improved? A bunch of wishy-washy observastions by students are not likly to be a stronger arguement than an assessment by a qualified ISA CA, TRA. This letter does not clarify anything in my mind, how will it clarify anything in the publics?*
 
Re: \"We\'ve got a tree that was scaring people.\"

Sorry about the state of the above. I need to edit the above later today so that my comments are more easily recognized.
 
Re: \"We\'ve got a tree that was scaring people.\"

[ QUOTE ]
Sorry about the state of the above. I need to edit the above later today so that my comments are more easily recognized.

[/ QUOTE ]o they're plenty recognized; many are agreed with, but do not call for a change. the main difference comes from reading more into the words than is there. it'll be in the paper soon; i'll post a link then.
 
Re: \"We\'ve got a tree that was scaring people.\"

mr, the readers of the op-ed piece have already had full access to the 2 reports. most of your responses exaggerate my words, but i'll give it a shot:

Hollows:

Are they important in TRA or not? the comments latter concerning (t/r) indicates not.

& yes but they are not the only important feature.


Cores could have shown the real strength in that wood,

How does a core show the real strength of the wood? It is not a strength measuring device. It might help to show the thickness of wood but not strength.

& by handling and examining the core you can feel how strong it is, and get a lot more info than thickness

Archaic tree risk assessments zero in on the wood thickness outside the cavity, using a discredited engineering formula, artificially high thresholds, mistaken assumptions, and invalid calculations.

What discredited engineering formula? Is the suggestion that t/r has no use in TRA or that t/r<.3 needs to be reconsidered.

& it needs to be kept in perspective, as Brudi does, not as a stopping point, as B******* does.

Commonly used formulas are derived from engineering inanimate objects, like pipes. However, “Trees are not pipes”, according to a BMP coauthor.

Does this mean that engineering concepts are never applicable to trees?

& No, not never.

ISA BMP: “Ratings are not cardinal numbers, but ordinal numbers. Adding or multiplying ordinal numbers does not yield a mathematically valid result.”


IF that is true either ISA TRA and BMP are at odds or risk assessment calculators as shown in ISA/PNW TRA manual are incorrect (and therefore many other methods)

& Maybe both! If TRAQ looks like TRACE they may have problems imho.

Species failure profile of white oak shows high resistance to decay and failure.

Where these profiles?

& In experience, and in forestry books

Assessing load would have shown that pruning reduces risk significantly.

Pruning at the ground would also reduce risk (and this is what two companies suggested)

& well yes burning the woods to ashes would also mitigate risk

How would load be assessd?

& watching the trees move in the wind, for starters. climbing the tree, next.

most of this work can be done by students, using comprehensive methods.

SO why have arborists trained as TRAssessors? Students can do it!!!!

& most of the info gathering, not all.

If the original companies could not do the job (adequately) how can a bunch of students with limited or no tree experience let alone a knowledge of TRA methodolgies?

& it's the crap methodologies (read the reports if you are that interested) that lead to inadequate assessments.


IF the issue is that the TRA was inadequate how is it to be improved?

& by getting more info from the tree than from machines.

This letter does not clarify anything in my mind, how will it clarify anything in the publics?

& It's hard to clarify anything by exaggeration.
mad.gif
 
Re: \"We\'ve got a tree that was scaring people.\"

It is bit hard to understand what you are suggesting. I take from this and recent posts that tapping a tree with a mallet and holding wood to feel how strong it is far better than tomography, resitographs, RCAs, formulas, material science etc.

I can just imagine in court "your honour, the wood sounded and felt strong"

Lawyer "What was the strength?"

YOu "It felt strong"

as compared to the consultant that says "I measured a shell wall thickness of 1.5inches; visual inspection and tomography showed that this was intact wood without decay. We consulted the material strength sheets of ... that indicates the compressive strength is 7000 psi."
 
Re: \"We\'ve got a tree that was scaring people.\"

"It is bit hard to understand what you are suggesting. I take from this and recent posts that tapping a tree with a mallet and holding wood to feel how strong it is far better than tomography, resitographs, RCAs, formulas, material science etc."

Wrong. Read again. I'm done responding to exaggerations.
crazy.gif


O and RCA; that's the record label with a Dalmatian on the cover, right?
laugh.gif
 
Re: \"We\'ve got a tree that was scaring people.\"

They printed it as written, with only one addition, to attribute a quote. I did not want to "out" any company or person, but the paper did. The big yellow company that developed and practices the flawed methodology was not named.

Any tree owner or managing agency that gets a Tree Structure Evaluation based on drilling and little else may want to get a second opinion.

Do you recall the story about the 5 blind guys who tried to identify the elephant by pawing pachydermal parts? Well,

Q: How is a young arborist assessing a hollow tree based on drilling its trunk different than an old blind man assessing an elephant based on touching its trunk?

A: One calls it a snake, and the other calls it a removal. No difference really; they both call it wrong.

Moving on! Anyone familiar with the case (or not) who sees inaccuracies in the letter is welcome to respond.

http://www.roanoke.com/editorials/commentary/wb/313494
 
Re: \"We\'ve got a tree that was scaring people.\"

Ed Hayes had it right 10 years ago:

http://safetrees.com/risk_ArbNews_2002_12.pdf

Managing Veteran Trees
Old trees are sometimes called veteran trees.
Arborists in Europe have been focusing on
techniques to preserve veteran trees for
decades or even centuries. The steps to
consider include
• predicting the failure pattern that is to
be expected.
• outlining the options that would need
to be taken to prevent the failure.
• evaluating the outcomes of those
treatments over time.
 
Re: \"We\'ve got a tree that was scaring people.\"

I read an article long ago stating that the Brits have old records documenting that pollarded trees on their estates lived much longer lives than the same species of trees in the forest wilds.

Inferring that highly maintained and pruned trees can live longer more productive lives in a man made environment than in nature.

I believe their supposition may very well be true, atleast with certain specific tree species like sycamores and other deciduous hardwoods.


jomoco
 
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