Originally posted by netree
Cut the stub back by making a proper collar cut. The tree will compartmentalize the wound relatively quickly, and greatly reduced in the long run.
Jimmy... what about ANaerobic bacteria?
Jeff, welcome to the site. We get a lil rowdy now and then, but you can pick up alot of good stuff.
Erik
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www.netree.org
Not particularly picking on netree, but let me try to tidy up some of my observations about a few items in the thread:
Shigo talks about the preservation of the collar as not interrupting the vessel path from above that is diverted around a branch.
There are two continuities, or layers of vessels, to maintain when a living branch cylinder is joined to a larger living cylinder.
The trunk vessel system has to get around every branch to continue down to the roots. The branch vessel system has to come into the junction and re-arange itself so it too can continue down to the roots.
The branch bark collar is the location where these re-arrangements take place, and the collar is generally larger than the original branch because the collar also has trunk vessels added to the incoming branch vessels.
Every cut removing a branch itself eliminates that whole branch vascular system as a contributor to the tree. There are no sugars available anymore to the cell maintenance of branch vessels or to the branch cambium that created the branch diameter. That loss is basic to the pruning of each and every branch we select to cut.
If the collar is left alone, the trunk vessels can continue to divert around the old branch location. The collar is the containment for that bypass and the flows of water up and sugars down is continued.
If the collar is cut as in a flush cut, the trunk bypass-the-branch paths are interrupted at the top and the bottom of the collar junction. There is no longer a direct path in that area around the branch and down to the roots. The flows of water up and sugars down, is ended.
The larger the branch diameter, the wider the area above and below the branch that is now out of the vascular system.
We agree that the loss of the branch means that half of the combined supply system that is re-arranged in the collar is gone forever.
If the collar stays intact in a Shigo cut, the above supply from the crown stays intact and is available to supply the surrounding cambium for closure of the wound.
Cut off the collar completely in a flush cut, and that last top half of the collar supply is is interrupted as well. The area below, as a width of the diameter, becomes a sort of "dead" zone and that's where epicormic growth generally appears to try to be replacemnts for the missing limb. The next avaialble supply sources are the unbroken trunk vessels immediately to each side of the flush cut wound. It is much less common to see that same growth response above the pruning wound.
Closure in a non-Shigo cut is slowed significantly mostly because there is now a smaller supply of sugars, and the diffusion of sugars from the side untouched vessels is small comparatively to the robust original configurations.
At the time these understandings were formulated, closure time was very important to Alex, and closure times were a subject of great debate.
I believe we should think in tree time; the time scales that trees have developed over their evolutions for different processes and functions. It may be very naive to think that we can alter them in line with our silly ideas of instant everything and satisfying our senses of convenience.
Chainsaw are a staggering new type of wounding to trees and CODIT. We create multiple unnatural wounds simultaneously, and wonder why closure isn't fixing them.
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If Hamons can reach into the branch stub and have his hand enter the trunk, that's a real clue that compartmentalization has not taken place sufficiently--it seems to have failed its original intention. Cutting the remaining stub any distance from the collar <u>is not</u> a fresh wound, <u>will not</u> initiate compartmentalization.
<u>CODIT was initiated when the 8" limb was first removed</u>. Closure is a rather independent process and should not be confused with CODIT proper. Closure also often hides the continuing decay from us and gives the false impression that any internal structural deterioration has ended.
Cutting a dead branch or shortening a dead stub is nor wounding in my book, and it doesn't start up CODIT bcause CODIT had already begun when the limb died--by saw or by other causes.
Jimmq is correct in saying drilling a drain hole will be a fresh wound in the already CODITed wood. That act puts at risk for decay, all the wood created from the original time of wounding up to the time of the drill wound. Not a good deal...
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Death and wounding initiate CODIT as a tree's best effort interrnally to anticipate and delay decay.
Wound closure does not signify the end of internal decay. Closure is presently misunderstood as an achievement in a tree's defense to continued deterioration internally. It is not.
Speeding closure is an interesting goal, but closure and its speed depends mostly on tree vigor and external conditions. It is more mathematical than anything else, and likely can never be faster than the division and maturation time for its cambium cells.
Tree paint won't accelerate closure; leaving the collar means the closing edges can come in from a fuller circle--which appears to be accelleration, but I consider it more as increased area coverage-- at rather the same rate.
Bob Wulkowicz