treevet
Addicted to ArboristSite
Great thread, probably the best learning thread so far this year, and I'd like to thank you guys for all the knowledge and contemplation that's being discussed here.
I'm out of my league by a mile, and I know it, but I've gotta ask a few questions to hopefully understand better.
Alot of this discussion has centered around the time it will take for wall 4 to form and prevent further pathogen entry, but isn't how well wall 1 will block decay from entering the main stem a more important factor to the health of the tree as opposed to the health of the limb in question?
And isn't how wall 1 will respond primiarily determined by species?
Once the wind or ice has broken the limb the decay pathogens will begin their work regardless of wether we do nothing, node trim it, or make a larger cut at the stem.
So it seems that what we're risking is the growth that occurs between the node trimming cut and how much more new wood we'd have to wound if the limb was removed at it's origin several years later.
All the wood present at the time of wounding is subject to decay, correct? It's up to the tree to compartmentalize the decay as well as it's able. So if we node trim it, and it resprouts, but then slowly declines and dies, and we must return to make the larger cut at the stem, now we've got all the new growth since the original injury being wounded and subject to a greater amount of potential decay.
But if the tree can successfully compartmentalize the decay and successfully resprout and maintain growth, we may have kept the decay from reaching the main stem at all.
I'm having a difficult time seeing how either option could be correct ALL the time. So isn't it up to us to analyze the variables in each individual situation to allow the tree the best chances to keep the largest percentage of it's mass healthy over the longest term possible?
That is a very thoughtful post. Most noticeable is the fact that the very large, very much abbreviated stub will have to be removed later and the walls will have to be re established. Also the loss of potential woundwood that would have occurred in the interum if the parent cut was made initially. Also I do not agree with the correlation between sprouting and compartmentalization. I have seen many large diameter stubs incur decay regardless of the amount of sprouts or success of laterals and this is a vector into the main stem that would otherwise have been protected by wall 4, etc. and has not had the means to form them with the stub still attached.
I think a highly compromised limb/leader (12" by 10 foot lgth) will be failing regardless of sprouting and therefore the walls (or some kind of cone Sanborn describes) will be weak and failing/shifting in nature.
There are of course exceptions to every rule. But Sanborn and Meilleur are advocating leaving these giant stubs all the time and not monitoring them. I see that is unprofessional and irresponsible.
It reminds me of the new appearance on some of the forums by posters of advocating indiscriminant tree topping and calling it pollarding, 2 vastly different treatments.
"To keep the largest percentage of it's mass healthy over the longest term possible?" I think not as I said earlier that decay or structural risk can be a larger issue than physiological health if targets abound. If they did not, we probably don't get the call anyway.