longer cuts on poor compartmentalizers| CODIT WALL4

treevet

I apologize for that last paragraph, I do not want to be like that.

I d like to add to last post. "Wall 4 is a boundary that separates wood present at time of wounding from the new wood that continues to form."

Callus is not wood. It has little or no lignen.

I d like to quote a section of Shigo "Tree Pruning"

"After wounds injure wood in living trees, a long series of physiological and anatomical events take place. The first response is an electrical one. Then chemical changes take place. Stored energy reserves in living parenchyma cells are converted through long biochemical pathways to substances that are inhibitory to most wood inhabiting microorganisms. The substances form a boundary that resists the spread of microorganisms into the wood. The boundary also defends the liquid transport, energy storage, land mechanical support systems of the tree. This boundary is the reaction zone.

Then the cambial zone about the wound resumes growth, the newly formed cells differentiate to form a boundary that separates the wood present at the time of injury from new wood that will form after the boundary is completed. That separating boundary is called the barrier zone.

On the margin of the wound, the cambial zone produces large, undifferentiated, nonlignified, homogeneous cells called callus. As callus production continues, some of the cells begin to differentiate to form transport cells-vessels, tracheids- and fibers. When these cells become lignified, then we have woundwood.

It does not say that after the barrier zone is formed then (then) callus is formed. It may be formed at the same time and be part of the zone. Also I have read that callus contains inhibitory chemicals, too, giving credence to the possibility that it may be an aspect of wall 4 (when one forms when injury occurs as none may occur if energy reserves are low or nonexistent).

PS I could lay up at night thinking about this

D Mc

Treevet, no worries; no offence was taken! We got quite a chuckle out of it, because we do indeed lay awake at night thinking about these things.

You expressed your thoughts very well. We are not sure what Ekka is thinking because it sounds like he is saying that without callus growth there is no Wall 4; and yet in pictures by Gillman, Shigo and Mattcheck they all point out Wall 4 being at the growth ring immediately after the injury. Which in future years will have healthy growth outside of it. However, callus growth is outside the tree at the point of injury and doesn't extend into the tree (with the exception of occlusion at the edges of the injury).

The study that Ekka sited in his last post was referring to debarking while living cambium remained attached to the tree. That in itself makes things a bit confusing as it is not the only time Wall 4 is activated.

So just trying to clarify these thoughts in our own minds as well.

D and S Mc

treevet

I think some picture this 4th wall as the closure of successive years of woundwood as Mr. Underwor stated. This is obviously incorrect.

Underwor

Treevet, Thanks for making me go back and study some more. You are correct!!!! Now I have to correct myself in class on Tuesday!! Wall 4 is chemical in nature and as I see it keeps the decay from making a flanking move around the edge of the wound into the wood that forms later. Once this wall is established, then woundwood can cover the outside and seal off the face of the injury from further pathogens.
Here is a link to an image that I took in 1986 of a hackberry that was repeatedly wounded. We can see where many wall 4s were established and breached by the enemy (Leroy and his string trimmer).

http://165.234.175.12/photos/Arbor/mowerslab.jpg

__________________
Bob Underwood, Associate Professor of Forestry
ND School of Forestry
Minot State University - Bottineau Campus
Bottineau, North Dakota

treevet

Yeah, Bob If woundwood was wall 4 and given it closes approx half an inch per side per year, a six inch cut would take 3 years (in this theory) to offer protection. If that was the case, every house in the neighborhood would be wearing trees as hood ornaments.

Ekka

I fixed that link up for you.

Here's what that doc wrote about wall 4.

And a copy of the diagram.


So what we do know is wall 4 has to be grown and is not a change in existing cells but new cells.

Carefull with this thinking or statement.

Whilst it can extend beyond where callus has grown it only does so where there is wood not where there is fresh air ... like when a car swipes a tree and takes a chunk out including bark the barrier is set up where there's still bark on the outside but not where the callus failed to form.

Where there's no bark it appears the progression is to form callus as well as the wall.

Here's the illustration and take note of the blue arrows and note the thin orange barrier does extend beyond the wound but only where there is wood.

So whilst you can have one with out the other it appears so only when contained within the woody system of the tree. And that debarking experiment showed how it is formed in the absence of bark (open wound) with callus.

Attached Images

	coditwall4sketch.JPG (37.8 KB, 112 views)
	coditwall4sketch2.JPG (65.2 KB, 185 views)

__________________

Free Tree and Green Industry Link Directory

Qualified Brisbane Tree Lopping | Stump Grinding and Stump Removal Brisbane

Brisbane Tree Care, Consultations, Developer, Tree and Arborist Reports

Forum Sponsors

treevet

[quote=Ekka;22355]I fixed that link up for you.

Here's what that doc wrote about wall 4.






That is some really cool stuff you ve got there. I knew it looked familiar so I dove into the Shigo section of my library and found it.

This is from the US Dept of Agriculture, Forest Service Ag Info Bul #419 titled, "Tree Decay, An Expanded Concept"
April 1979

I showed this incredible book with the most beautiful and descriptive illustrations to Dr. Shigo and he was amazed I had it and signed it on the front, "Dave Shaw, "Touch Trees" Alex Shigo (Sig) 9/7/97.

This was the beginning of Modern Arboriculture (approx) and part of why he was named the "Father of Modern Arboriculture" a few years ago. He was just a plant pathologist at that time for the US Dept of Ag.

The dramatic aspect of this was the dispelling of the "heartrot concept"

From the intro, ".....include the orderly response of the tree to wounding and infection-compartmentalization-and the orderly infection of wounds by many microorganisms-successions. The heartrot concept must be abandoned because it deals only with decay causing fungi and it states that these fungi grow unrestricted through heartwood after infection of fresh wounds. The heartrot concept emphasizes descriptions of decay causing fungi and types of decayed wood. It describes disordered wood and events that occurred in the past. The expanded decay concept emphasizes the order of a compartmented tree, the order of compartmentalization and the order of successions. Regulation of discoloration and decay depends on understanding compartmentalization and successions."

This changed how we look at and treat trees!

Shigo cut probably thousands of trees in half (lengthways!) while researching this theory that describes compartmentalization and all the thousands of hours involved that resulted in the CODIT model.

This is why it is hard to take some poster laying on the couch watching reruns of sitcoms eating a bologna sandwich (a similar effort) and comes up with changing one of the words of codit from decay to dysfunction or something like that, and at the same time says someone will come along and update, alter or somehow improve on this modern day genus theory and other revolutionary changes he made. I really wanted to ignore this but could not

Sean Freeman

Treevet, your passion for the foundation work laid by Alex Shigo is matched by the same from many here in Oz of that you can be sure..........however having heard and seen(on video) Shigo explain how important it is not to stop questioning everything, making certain (or as ceretain as we can) that we understand what is happening inside the tree why, how when and where. He always seemed only too willing to aknowledge that the work didn't stop with his writings, rather that is where it starts.

I like to believe that he would have no qualms about Arbs trying to make the model fit more accurately what they are actually seeing inside the trees they dissect, by altering the emphasis from decay to disfunction. He would want that change carefully explained justified and demonstrated for sure.

__________________
Sean

Trees are poems that earth writes upon the sky,
We fell them down and turn them into paper,
That we may record our emptiness.
- Kahlil Gibran

Ekka

To try an clarify my postion, my understanding and my view I made a video.

Ekka's explanation of wall4

__________________

Free Tree and Green Industry Link Directory

Qualified Brisbane Tree Lopping | Stump Grinding and Stump Removal Brisbane

Brisbane Tree Care, Consultations, Developer, Tree and Arborist Reports

Forum Sponsors

treevet

You are, of course, completely right, Sean.

The reaction I guess is not so much for (for) Alex Shigo, the scientist, but more for Shigo, the person. There would be a tendency, probably, to when considering this man and his work, to be maybe an intellectual, somewhat robot-like through decades of research. Maybe like I am thinking of Albert Einstein or someone like him right now. Nothing could be further from reality.

I was lucky enough (and to have enough foresight) to have spent hundreds of hours with him (among differing size groups) choosing to base most of my education time on him from 1980 on. I can fly for free as my wife worked for the airlines.

He was a father figure to me having lost my father around that time. He was that way to many. He was mainly a mentor. He would often go off on tangents philosophizing and joking with a magical personality about so many things that he made you feel whole, if you know what I mean. He always had time for you and made you feel like you were the only important thing in the world when you spoke with him personally. Everyone he was involved with lifted their game a little no matter where that game started or ended. He made one feel good about themselves. He was the ultimate teacher, as his best friend, Charley Owen once said, and that was a large part of his genus.

So excuse me if I overreact to any perceived slight, right or wrong, much like someone would for parents, siblings or good friends you would stand up for.

Again, you re completely right. Have the passion and question everything and if you want to make a point, make sure it is based in research involving the scientific method.

treevet

You did a very good job of explaining yourself but I have a few questions. Not verbatum, but you say "heartwood, deadwood, nothing going much here, not doing much, no live cells". The first growth rings store carbohydrates, they take them in and release them for use. On page 48 of A New Tree Biology a red oak with a shot gun wound (sudden injury), wall 2 showed inward spread resisted but a dark band of discolored heartwood surrounding the decayed wood outside the heartwood and the new growth rings, acting as a defense boundary is apparent. Shigo's quote "heartwood does compartmentalize.

You mention no chemical boundary ( or maybe once), and you assert wall 4 grows, leaving one to assume you mean the woundwood or rams horn ( uncontained cells). Interesting note, In New Tree Biology no mention of woundwood, then, later, in Modern Arboriculture there is. I m sure subsequent research revealed the difference btwn callus and woundwood (lignen, etc).

Your assertion seems to be wall 4 is only created by uncontained (unpressured cells) and chems are not involved and this is callus and callus is an annual growth that forms closure and sometimes rams horns?

You mention "They found" . Are you basing your knowledge on someone other than Shigo s? Can we search them?

Research shows callus grows in only the 1st 3 to 5 weeks, then some cells differentiate and become lignified to form woundwood.

I still think callus is part of wall 4 and it's and other reactive chemicals across the span of the wound developed by heartwood and possibly traumatized cells dieing on the face of the wound are the wall. All the closure is just life going on (or not).

PS. after watching your vid I thought you started another thread about your video?

Ekka

All of the information for the video is sourced from this thread. Like a few posts above those pics are from links within this thread.

I believe wall4, whatever it's chemical properties are, is grown after the event. Take a look at all the diagrams, pictures and micoscopy. You dont see it within the current years rings but as part of the next years or growth.

Also, if it was existing cells within the current years growth that changed to some chemical barrier yet tangible and see-able with naked eye it would be present on the face of wounds where no callus formed. But it never is. It is always accompanied by wood on the outer side of it.

When you get a wound you can have localised growth. Like a pruning cut starts to form a doughnut. And you can get your normal growth rings to. Sometimes the two work together. However, again look for yourself, do you think it possible for that thin wall4 to generate normal ring growth afterwards? NO? So where does the wood come from then?

I say it was already there and when it is there it morphs to wall4 laid against the wound.

Now regarding heartwood compartmentalizing and having stored stuff, sure, but it is not alive, it doesn't generate new cell growth, it's a sink. However Rays which are connected between living cambium cells and dead heartwood can transport deep into heartwood, that's what helps stop radial spread.

What I'm trying to focus on here is wall4 which occurs on the outside of wounds, the growing side of wounds.

__________________

Free Tree and Green Industry Link Directory

Qualified Brisbane Tree Lopping | Stump Grinding and Stump Removal Brisbane

Brisbane Tree Care, Consultations, Developer, Tree and Arborist Reports

Forum Sponsors

treevet

This span of tissue inside (within the wound) the perimeter of the callus, not living tissue as we know it........already breached by successions of opportunistic decay causing orgs.......and contained inwardly by wall#2 (twds the center of the stem) (if a tree is injured it is infected)

....this span, what protects new cell growth and annual growth of woundwood on this span from these pathogens already inhabiting the inner aspect of the stem?

What I see is wall 4 within the perimeter of callus is entirely chemical and formed at the time of trauma.

"The discolored heartwood acts as a defense boundary. Protection boundaries are static and formed after injury and infection. Defense boundaries are dynamic and formed after injury and infection. Heartwood does compartmentalize." Shigo

Maybe we are saying the same thing but your term "grows" the wall, I am not clear on.