UKTC Archive

RE: Science and Arboricultural Investigation

Subject: RE: Science and Arboricultural Investigation
From: Addison, Gilbert
Date: Jul 14 2009 07:55:18
I am appreciative of this open and frank discussion in public - thank
you Jim and Marcus and others. I wish TI was zero cost as my foremost
fear is that weight is apportioned evidence in proportion to the cost of
obtaining it! This applies to all the latter day "high tech"
investigation techniques. The oft neglected element of any investigation
is highlighted by Jim as site history - indeed I would raise Jim in that
I always tell people that you need to know the history of the last 30

Gilbert Addison
Tree & Countryside Officer

Breckland Council 
working in partnership with

Tel:  01362 XXXXXX
Fax: 01362 XXXXXX
Elizabeth House, Walpole Loke, Dereham, Norfolk, NR19 1EE

-----Original Message-----
From: Jim Quaife [] 
Sent: 13 July 2009 19:01
To: UK Tree Care
Subject: RE: Science and Arboricultural Investigation

I would be grateful to have links to your paper/website.
I have mused on this thread and there are two primary imponderables to
my mind.
1.  You are clearly a long way down the road as far as analysis is
concerned but the translation to diagnosis is I suspect in its infancy.

Any tool that assists the arb in the minefield of risk evaluation must
be welcome in principle, but I was particularly exercised about one
picture that Andy showed us of a Lime where there was a blue zone on a
secondary stem emanating from 3 metres or so with a couple of others.
The blue section of stem had pruning wounds and some juvenile shoot
growth and was, according to the text alongside, doomed.  Firstly there
was nothing visible in the normal photograph that would lead one to have
any pronounced concerns, and secondly it missed what could have been an
included bark fork between the other stems.  I'm not about to burst into
tears over a photograph without seeing the tree, but the pictures were
very misleading because they ignored any consideration of foliage
condition, shoot extension and so on.
2. The individuality of each tree makes statistical analysis awkward. On
the basis of visual and thermal inspection one is making a decision on
probability, which of necessity is a mixture of relative and subjective
judgement.  That much is where we are at with all tree assessments, but
the dividing line between "evidence" and intuition/experience/knowledge
remains highly subjective.
The statistical population is so variable with trees that one must be
careful about generalisation.
If one considers VTA, as a snapshot it is useful but is much enhanced by
working out what has been happening to surroundings of the tree over the
pervious 5 or better still 10 years.   Taking the "blue zone" (must be
careful - I don't want to be moderated here!) the thermal image is a
snapshot.  Is the tissue deteriorating or "getting better".

I'm still struggling here and my thoughts are a little wavering, but I
guess I just need to understand more of the ins and outs.  Andy raised
my perception from about 5% to maybe 45% (15%?) but for me to have the
confidence to condemn a tree or a part of a tree because the bark is a
bit cooler is quite a leap of faith.  If the technology is capable of
discerning internal knots then I would be fascinated to read the nuts
and bolts.


P.S. In an uncharacteristic fit of remorse I intend to send Andy some

-----Original Message-----
From: Marcus Bellett-Travers []
Sent: 13 July 2009 09:54
To: UK Tree Care
Subject: Re: Science and Arboricultural Investigation

Jerry what you say is true but this has also been done.  We have over 30

Licensees and 500 clients to service, so the opportunity of doing this
kind of thing again has probably passed but as I said before we have 4
research projects out there so there will be publications and this kind
of thing may come up again.

I am more interested in Jim Qs comments at the present time.  This was
the subject of a paper I gave in Turin last year, which was published, I
think, but is also available on our web site.  He is quite right as
usual, there is no point having these tools if the information they
provide cannot be put into context.  The paper I gave showed how you
could do this with all tools not just TI and layed out the pros and cons
of all methodologies, whether they are purely VTA, Mechanistic models,
statistical relationships, or combinations. Because it had a ballanced
apparoach it was very well received.  The obvious advantage of TI though
is that you can collect the necessary information very quickly.

It may suprise people to know I have given a great deal of support to
both the PICUS and Resistograph, because we have been able to gather
information quickly, we have been able to answer some fundamental
questions relating to these two technologies very quickly.

----- Original Message -----
From: "Jerry Ross" <>
To: "UK Tree Care" <>
Sent: Monday, July 13, 2009 8:16 AM
Subject: Re: Science and Arboricultural Investigation

Marcus Bellett-Travers wrote:

There aint much left to publish at the research level, as I have said 
before it is all out there.  The clever bit was the computer programme
tie the loose ends togther into a usable system and this is the bit we

cannot publish, it would be like Bill Gates publishing the algorythms 
behind Windows.

Like Linux, you mean?

(Sorry Marcus - couldn't resist that!)

What you say takes care of the theoretical background. But I think where
people's concerns arise is the lack of an independent (or at least
independently reviewed) study of the results of your tests. Or of some
sort of experimental study. Take a site where a dozen trees are going to
be felled; get various practitioners to survey them using various
techniques (VTA, TI, Picus, Resistograph, hammer), then fell & dissect
the trees and compare and contrast the results.
That wouldn't compromise any IP rights.
It would take time and money, and ultimately may not be statistically
significant (it can always be argued that there are too many variables &
too few samples)  But it would be very interesting!

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