V.T.A symptoms "the chatty trees"

[Tony Croft aka hamadryad]

As the last thread i started on the subject was rubbish in one way or another, here i go again:lol:

 

So starting off with the fork ears or "stazi ears" as claus likes to call them, a symptom associated with included bark, usualy in twin or multi stemmed trees, but the symptom has a similar external symptom as a crack through the stem which is represented as a rib. (not to be confused with force flow!) and don't worry, I will elaborate as we go.

 

The "Stazi ear" or compression fork caused by included bark acting as a crack within the union.

 

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Edited February 23, 2011 by Monkey-D

[mrtree]

It is my understanding that the ears do not act as a crack but rather are a reaction to the growth form of the tree (ie. V-crotch two stem). In fact they are not a crack but rather an attempt to join the two stems, effectively they are strengthening the union. Of course unions, even with included bark are not inheriently weak, it is the reduced cross-sectional areas of attachment that is the problem.

 

I think a critical analysis of trees with ears and lots of years of growth will show that they are an effective method to "brace" or "through-rod" the union and can become quite strong.

 

When I see this sort of ear in most landscape/urban trees the tree does not last long as the ears are interpreted as a sign of weakness not as a sign of recover and strengthening. Some tree service or "arborist" does a quick visual assessment and says remove. This is very common particilarly in some elms, ashes and zelkovas. Throw in the idea of risk and liability and trees disappear so early that we cannot see too many examples of veteran and really old trees with ears in the landscape.

 

If we look at something such as the new DMM impact blocks we see an increase in metal thickness which has been designed into the form to add strength. If we look at trees in a similar way, change our mindset from the beginning, then we have trees that are savable not always a hazard.

 

I bet this is part of what Hamadryad is about to say.

[Stephen Blair]

good stuff Tony, i was looking at some beeches a couple of weeks back, ribs and reaction wood tastic i thought on the trunk and limbs, the woodland is unmanaged and sapplings and coppice have been neglected for 40 odd years, so the beeches have had to work hard to find the light.

Do you have any cross sections of reaction wood? I am interested to know what it looks like and what effect it will have on the value of the timber, 1 for looks and 2 for strength, diferent uses etc.

[Tony Croft aka hamadryad]

it is my understanding that the ears do not act as a crack but rather are a reaction to the growth form of the tree (ie. V-crotch two stem). In fact they are not a crack but rather an attempt to join the two stems, effectively they are strengthening the union. Of course unions, even with included bark are not inheriently weak, it is the reduced cross-sectional areas of attachment that is the problem.

 

it is not the ears that are the crack, the ears are multiple layers of woody tissue growing over the tip of the false crack which is the included bark (bark to bark contact. The tree is trying to close or weld the seem together the more pronounced the ears the more active the crack.

 

i think a critical analysis of trees with ears and lots of years of growth will show that they are an effective method to "brace" or "through-rod" the union and can become quite strong.

 

this work is old, and included bark is well documented, a lot of this is known through the many thousands of dissections carried out by dr alex shigo, later mechanically evaluated by prof dr claus mattheck. Lastly, i would thoroughly reccomend laying your hands on both of these great mens works, it will illuminate the issues very well indeed. It is also worth taking time to investigate for yourself as a walk in any ancient woodland that remains relativley un molested will quickly enlighten even the most uncertain of this defects potential. (pictures attached)

 

when i see this sort of ear in most landscape/urban trees the tree does not last long as the ears are interpreted as a sign of weakness not as a sign of recover and strengthening. Some tree service or "arborist" does a quick visual assessment and says remove. This is very common particilarly in some elms, ashes and zelkovas. Throw in the idea of risk and liability and trees disappear so early that we cannot see too many examples of veteran and really old trees with ears in the landscape.

 

the reason they dont last long is because this is a known defect however felling is not needed, reduction and as you say rod bracing is the answer here. But lets also allow some to fail, they create micro niche habitats, or ariel gardens that i adore as much as the wildlife does:001_cool:

 

if we look at something such as the new dmm impact blocks we see an increase in metal thickness which has been designed into the form to add strength. If we look at trees in a similar way, change our mindset from the beginning, then we have trees that are savable not always a hazard.

 

the fact the ears do not in any way shape nor form conform to the tensile triangle (optimal flange design seen in all structures both in geology and nature) is the problem, design optimisation? Ears are not, they are a desperate attempt to salvage a dangerous loss of main stem, hence the rapid and desperate deposition of wood arounf the fault line.

 

i bet this is part of what hamadryad is about to say.

Hope you didnt have money riding on it!

 

As a rule i detest artificial solutions like bracing, reduction mimics natural retrenchment and is the ideal method of defect management imo

 

 

 

 

[Tony Croft aka hamadryad]

good stuff Tony, i was looking at some beeches a couple of weeks back, ribs and reaction wood tastic i thought on the trunk and limbs, the woodland is unmanaged and sapplings and coppice have been neglected for 40 odd years, so the beeches have had to work hard to find the light.

Do you have any cross sections of reaction wood? I am interested to know what it looks like and what effect it will have on the value of the timber, 1 for looks and 2 for strength, diferent uses etc.

 

Your tree is in the old class, and beyond an age selected for timber usualy, its discontinuos trunk and obvious force flows show a now well matured ripe wood heart, probably in early stages of decay and or discolouration but maybe not beyond decorative uses, ian leach might like it!

 

as for higher up at the union it will be seperated at the core by an included bark region and above this the lack of connection will be a constant.

[Stephen Blair]

thanks Tony, sorry i meant reaction wood in general, and is its speed of growth determined by the stresses involved?

[Tony Croft aka hamadryad]

The V.T.A (visual tree assessment) system as devised by Claus Mattheck works, a lot of people misunderstood some very basic elements and these misunderstandings still persist, but IMO and IME knowing trees and decay and defects as well as i do i can not recommend the system highly enough.

 

The system is still being applied in a less than sympathetic way, but this is mostly due to a lack of individual experience with the practitioner rather than a fault in the system.

 

Claus designed the system so we could live WITH trees, not so we could eradicate each and every tree that showed decay or defect.

[Tony Croft aka hamadryad]

thanks Tony, sorry i meant reaction wood in general, and is its speed of growth determined by the stresses involved?

 

Stress is the cause of a rapid deposition of wood to compensate for a weakened state, this will be most pronounced at the highest stress region.

 

but we must be sure to distingiush compensation from force flow and vigorous growth which can sometimes be hard to tell apart, in your case i feel it is a combination of both, but remember that rapid growth is a good indication the tree can and is dealing with a defective part and re balancing the axiom of uniform stress:thumbup1:

[Stephen Blair]

cheers:001_smile:

[Tony Croft aka hamadryad]

Of course unions, even with included bark are not inheriently weak, it is the reduced cross-sectional areas of attachment that is the problem.

 

One of my favourite Inclusion failures, and only a sniff of decay:001_smile: