Load reduction vs Cabling

KevinS

KevinS

Branched out member
Location
ontario
So I'm sure I'm in over my head with this but here it goes.

Everyone knows that when you cable it should be paired with pruning. I have no problem with this. I've been told and after enough time I agree, that reduction pruning, entrenchment, etc. can often do just as much good as cabling.
Any of these tasks strive for the same goal to reduce stress. Whether it be for crotch, cavity, inclusion,etc.

Now I'm trying to figure out structurally when it's advantages to prune vs cable. Obviously if the prune would make a wound to large to heal on a mature/ declining tree a cable with a lighter pruning would work aesthetically and a young thriving willow could withstand a more heavy handed pruning to avoid cabling.

When do you guys draw the line between cabling and not? Purely for structure and tree health we'll leave the beauty factor out.
 
Guy is right it depends so much on what outcome you are looking for. But also What are the hazards? What are the targets? Can the targets be reduced or moved completely? What is the tree species? All things to consider carefully.
A big old willow in a children's playground I might get both pruning and cables but put that same tree on someone's lawn with no significant target and a lighter pruning with no cable. River birch is one I try to prune heavy and no cable (unless it's non-invasive).
 
Fair enough, I agree as well and that's the point I'm at. I'm working on an in house hazard mitigation policy I know every tree's different and go with my best sense and gut per situation. But putting go with your gut on a company policy, I don't think the boss will go for that.
I've got research that says 10% reduction reduces load by 20% obviously assuming you prune it in the most advantageous way.
But I can't find a range of how much support cabling gives, I assume because it's more dynamic and cobra has more give than steel etc.

Some of my guys have told me they can go and assess a defect all they like but they don't have a good grasp on how and how much to mitigate it by. If they're unsure then there gut is unsure so I'm trying to fill the gap even a little between my gut and there reasoning.

That's my actual dilemma. Maybe that will help.
 
I actually refuse to give a % reduction because of how arbitrary it can be. There are too many different views of what is what. Do you do it by leaf area, basil branch area or pile it up and estimate volume? If I sell a reduction or cabling my gut tells me it is needed, from my experience. And when climbing I will reduce until I feel comfortable with the tree. Of course I try to stay with in A300 standards (using the pile/volume method) but sometimes you have to do what needs doing.
I think if I were to try and write a company policy trying to say that (first of all I would probably loose my mind) but I think I would go the route of defining the hazards, and the mitigation methods and let the individuals using the policy use their experience to prescribe proper treatment. And if they aren't comfortable with it or don't have the experience then let them shadow or work with someone that does so that they can grow and get comfortable.
It is a difficult dilemma, write a policy for such a dynamic topic that you couldn't hope to cover all the possibilities that someone would find and that could have so much of an impact if things went wrong. Good luck and I hope you share your final product with us when its done.
 
flyingsquirrel25 said:
I actually refuse to give a % reduction because of how arbitrary it can be. There are too many different views of what is what. Do you do it by leaf area, basil branch area or pile it up and estimate volume? If I sell a reduction or cabling my gut tells me it is needed, from my experience. And when climbing I will reduce until I feel comfortable with the tree. Of course I try to stay with in A300 standards (using the pile/volume method) but sometimes you have to do what needs doing.
I think if I were to try and write a company policy trying to say that (first of all I would probably loose my mind) but I think I would go the route of defining the hazards, and the mitigation methods and let the individuals using the policy use their experience to prescribe proper treatment. And if they aren't comfortable with it or don't have the experience then let them shadow or work with someone that does so that they can grow and get comfortable.
It is a difficult dilemma, write a policy for such a dynamic topic that you couldn't hope to cover all the possibilities that someone would find and that could have so much of an impact if things went wrong. Good luck and I hope you share your final product with us when its done.
Click to expand...

Thanks for that.
I have already compiled your suggestions and more but when I came to this part like I said I couldn't get my gut on the page. So I suppose it's good to be at the level I'm at and why I can find next to no research on the topic.

The closet I have is some biomechanics lectures, etc and they are exactly the answer but you need to want to put in the time to get into that stuff it's kinda dry, but important. I try to really push into biomechanics but like I said I'm ok with my gut it's the ones under me looking for an explanation.
 
Menardcch 1501 cable q alba.webp Menardcch 1501 q alba fork.webp See Goodfellow 2009; 15% off the end ->~50%+ stability gain.
Thank you for not putting your gut on the page; sounds messy.
I'm seldom ok with my gut so I use Tums, and my pineal gland.
Climbing into and flexing tree limbs is the best assessment method.

But on this one just looking worked ok. Pruning would have taken a lot more time than cabling, and uglified the tree, and the fork was too big and the target too high to cut out the inclusion, so a cable is specced.
Most biomechanics lectures are missing the BIO part, which accounts for the aridity.
"Of course I try to stay with in A300 standards (using the pile/volume method) "
If you actually try to figure out the standard you'll see it's not a recipe. (It reads more like a Zen mind game IMO.) 25%, 1/3 rules have little or nothing to do with compliance, but yeah I also use the pile/volume method, to check it for the heck of it, but other clauses are more important.
 
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Total side topic but I have mixed thoughts on the theory tall slender trees are a problem. I've got to go find the formula but if the tree/limb/section is taller than the dbh 'should allow' makes it a problem tree.

Does anyone have opinions on this?

My feeling is if the tree grew in an ok root zone and naturally, not continuously elevated or lion tailed to push elongation. But if that's how it naturally grows then it isn't too bad.
But if it becomes like this through human intervention it may be a problem.

Studies done on forest trees when wind aspects change you get a lot of blow down (uprooting). But is the tree any weaker. Obviously bigger base is better but is tall and slender bad?
 
Have a client this week who has some Box Elder that were previously cabled. They are all in a clump over the boat lift. He also wants to reduce them.

For this situation, I think both is a good combo.
 
KevinS said:
Total side topic but I have mixed thoughts on the theory tall slender trees are a problem. I've got to go find the formula but if the tree/limb/section is taller than the dbh 'should allow' makes it a problem tree.

Does anyone have opinions on this?

My feeling is if the tree grew in an ok root zone and naturally, not continuously elevated or lion tailed to push elongation. But if that's how it naturally grows then it isn't too bad.
But if it becomes like this through human intervention it may be a problem.

Studies done on forest trees when wind aspects change you get a lot of blow down (uprooting). But is the tree any weaker. Obviously bigger base is better but is tall and slender bad?
Click to expand...
This guy agrees http://www.isa-arbor.com/events/conference/proceedings/2013/presentationDescription.aspx?ID=952
 
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