Dead (and Undead) Wood

[guymayor]

Yeah it was nice when in A300 Part 8 we settled the trunk flare/root flare question by calling it 'the flare', and got some good guidance in the standard. John Britton in CA, a great mentor, pioneered this work.

There've been learning curve issues but in general Flare Care is an automatic add-on that's an easy sell. Clients understand the part of the tree that connects to the earth is kinda important, even when many arborists ignore it.

 

[UncleDon]

Great discussion, going on for several years I see. I agree with most of the above observations since 2008, and as far as the original question, I don't think you will find any real research on this that can say it any better than what all these professionals have done in pointing out the many variables and practical issues of site and species specific judgement calls that have to be made.
I like Redtree's comment on girdling roots, and I'm going to respond to that in another discussion on girdling roots.

 

[Redtree]

Ya I think your right uncle Don. Treebuzz gets some criticism, but it's the only thing on the web for Proffessional arborists, with a wide range of experience, to come together to express and criticize opinions.
Thanks treebuzz
And please criticize my opinion. Just do it gently. Looks like everyone here is good at that anyway. I'll keep reminding the American critics up here in Canada that u guys are more similar to us then some of us realize. Keep on rockin in the free world.

 

[treehumper]

As a Canadian ex-pat living in NJ, I can attest to the differences and similarities. The things that separate us as nations and bind us as allies and partners.

 

[Daniel]

Wounds stay open, and decay enters the parent, when the dead branch stays on. Wounds close when dead branches are removed.

That's been well documented..

Assumption check Guy..
Does wound closure help the tree???? Shigo had to get people past that notion... when he introduced codit..
interestingly Shigo based a lot of his conclusions on the presence of discoloration, a model that is still followed by researchers today..
unfortunately no one has the patience to wait 50 years to see what kind of discoloration leads to failure in white oak, before publishing..
Fortunately, common sense prevails where science cannot tread... (for those with a little common sense) LOL

 

[guymayor]

Good points about discoloration, and assumptions.

But I still think in general that wound closure helps the tree!

 

[oceans]

Good points about discoloration, and assumptions.

But I still think in general that wound closure helps the tree!

Wound closure does help, but when I think of Wall 1, I can't imagine that the tree would prefer having less material in place to determine at which point to initiate tylosis.

Is it blasphemy to think that a stub might be better for the plant in the short term? As far as I know, from straight up observations, the collar will form in the right place whether a stub is left or a proper collar cut is made.

The collar cut will certainly look better, but what if we leave a temporary stub?

 

[evo]

I do this all of the time at my house when pruning. If there is no collar, or just a hint of one I will leave a stub only to come back later to make my final cut. Other times I do this is when there is little to no chance of the tree occluding the wound. I do feel that it's better for the plant, but while working on a clients tree I also factor in when or if I will becoming back later that year, in three years, or perhaps never if they are selling the property.

 

[oceans]

I do this all of the time at my house when pruning. If there is no collar, or just a hint of one I will leave a stub only to come back later to make my final cut. Other times I do this is when there is little to no chance of the tree occluding the wound. I do feel that it's better for the plant, but while working on a clients tree I also factor in when or if I will becoming back later that year, in three years, or perhaps never if they are selling the property.

True. There are any number of factors that would influence our cut of choice.

What other trades are there in which a client can expect a return visit for proper attention and care over time (assuming a second pruning of a previous cut was a good idea)?

Also, what would be a determining length of a stub, and for what given diameter and species?

I have intentionally made several 2" heading cuts in a Maple to initiate a crown reduction where no laterals existed. The tree seems to have responded well. I should gather some photos of that.

When first doing the work, it looked like I left all sorts of stubs, but I see the tree often and it has new growth originating from the cuts. I tried to do this at nodes, and most were at co-dominant unions. Imagine a proper cut to remove one of the two branches, but remove both. That's what a lot of them looked like.

Of course this is different than stubs left with intention to remove. I was stunning to initiate new growth at a much lower height in the plant. Varied goals here, but each case can provide a learning experience.

 

[KevinS]

Sorry if this was brought up I'm only a few pages in. But I'm reading a lot of leave it to the trees they've handled things themselves for approximately a bazillion years. One flaw I see in this is 250,000 years ago Canada didn't really have Lime trees, Michigan didn't have chines elms, Norway maples were not container grown, we hadn't hi graded the forests with logging leaving the runts and rejects as the optimal seed source, nursery grafting and topping... oh wait what's a nursery, what's mono culture? Then there is the whole carbon sink ratio, then soil compaction yeah a t-rex was heavy but I think the I-95 is worse.

I'm no biologist but the pacific NW and a few places around the world are lucky to have ancient trees but times, environments, conditions, species geographic bounds are not held to there zones, etc. So yes trees are great and we only know some what how great they are but things are different.

Now I'm back to reading the last 9 pages

 

[guymayor]

"What other trades are there in which a client can expect a return visit for proper attention and care over time (assuming a second pruning of a previous cut was a good idea)?

How about the pet grooming trade? or MD? We care for living, dynamic organisms; can we be held to the plumber's paradigm? Where does this one-off expectation come from?

"Also, what would be a determining length of a stub, and for what given diameter and species?

1. Trust the tree and make it at at the the next distal node, where diameter narrows.
2. The Brits tried using mathematical formulae when reducing lapsed pollards, disregarding biology, and the tree's own advice. The experiments on beeches oak and ash etc. have not gone well from all I've seen.

"I have intentionally made several 2" heading cuts in a Maple to initiate a crown reduction where no laterals existed. The tree seems to have responded well. I should gather some photos of that.
When first doing the work, it looked like I left all sorts of stubs, but I see the tree often and it has new growth originating from the cuts. I tried to do this at nodes, and most were at co-dominant unions. Imagine a proper cut to remove one of the two branches, but remove both. That's what a lot of them looked like.

If your maple is vigorous and gets sun, that response is reasonable to expect. btw if you made the cuts at nodes, it was reduction, not topping. Not sure what 'heading cut' means.

"I was stunning to initiate new growth at a much lower height in the plant. Varied goals here, but each case can provide a learning experience.

Trees are the best teachers!

 

[evo]

Well I have left stubs on maples where there was not a collar, to come back a year or two to make a proper target cut. I've made the "topping" style cuts to simulate branching like you mentioned and also to create habitat.. I have also left big stubby dead wood as is when the tree would not have a chance to close it before it turned into a cavity. Another is when a large limb fails (or has to go for some reason) I will bring it back to between 3-8 feet (from the trunk) and make it look like a habitat snag.

My choices on what and when to make these cuts have to do with many different factors. Growth rate, species, risk tolerance (mine and the clients), and if it's likely the client will have me back (or anyone else to follow up). As I've mentioned before I live on a island which is a urban/rural interface. We are being developed at a crazy rate. We have it all here, from forest management to lot size parcels with non native landscape trees.

I tell my clients there is what is "good" for the tree, and then what is good for the forest/ecosystem. Trees don't need to pruned when taking the ecosystem approach, yes they have done this since the dawn of time. Veteran tree management on some slower growing landscape trees is great if there is the space for it, and the risk level allows. Most of the time pruning is done is for the clients needs, and not the tree. Sure there are cases where pruning is healthy for a tree, but more often than not I liken it to amputation. There are correct ways to cut your leg off (approximately less than 1/3 of your body weight) and ways that invite gang greene or leave your stub useless.

 

[oceans]

How about the pet grooming trade? or MD? We care for living, dynamic organisms; can we be held to the plumber's paradigm? Where does this one-off expectation come from?

Great examples. Perhaps people need to be reminded of how much trees are doing for them. Without an interactive relationship, their trees are potentially just giant stagnant problems waiting to happen.

Trust the tree and make it at at the the next distal node, where diameter narrows.

I'll look for this more often now. I hesitated a great deal to suggest or introduce that practice when working for anyone but myself and my own clients.

If your maple is vigorous and gets sun, that response is reasonable to expect. btw if you made the cuts at nodes, it was reduction, not topping. Not sure what 'heading cut' means.

I thought a heading cut meant no lateral branches existed.

Trees are the best teachers!

YES! And so are those that understand that. Thanks, Guy.

 

[guymayor]

"Great examples. Perhaps people need to be reminded of how much trees are doing for them. Without an interactive relationship, their trees are potentially just giant stagnant problems waiting to happen."
And with a little interaction with their friends, trees are giant assets waiting to appreciate!

"I'll look for this more often now. I hesitated a great deal to suggest or introduce that practice when working for anyone but myself and my own clients."
As I was embarrassed at first to suggest that collar cuts are not the best in damaged or older trees.

"I thought a heading cut meant no lateral branches existed."
That may be one definition. A lateral that is 'too small' is another. As with 'defect', that term has different meanings. Vagueness in standard terminology suits companies that sell by smoke and mirrors, but works against the rest.

YES! Keep up the experiments, and don't be shy about showing the results!

 

[KevinS]

My point was more the eco-system. Birds use trees as more than a place to rest or nest. Trees with deadwood have more bird activity. More cavities to nest in but more so, more bugs to eat that live in the tiny deadwood.

There may be merit to the theory that removing deadwood over "x" diameter is beneficial for urban trees but there is no merit (in terms of tree health) to nit picking pencil sized dead.

This kind of sounds like deadwooding the lower and interior of the tree but leaving the outer crown touched. For bugs and crud this may be efficient but on other threads I've seen it viewed as lazy unethical but I guess if that is worked out ahead of time it's not. The outer dead twigs are often smaller so they wouldn't effect to sunlight too much.

Insects often eat deadwood not live wood so it's not to much of an issue. However Trees under stress are more of a target for infestation of insects, so pruning the deadwood out is a medium used to control infestations of insects, correct?

Trees are hopefully more or less healthy but if you look at ash trees right now with the eab outbreak would pruning out the deadwood not make it less of a honing beacon for the bug? I understand it goes through healthy cambium but stressed trees are easy targets for them?

On that thought train what if the next major pest from asia starts out of nowhere next year with oaks or apples or .... would regular pruning now help them with preventative maintenance?

 

[KevinS]

Thank you Bob and Sean.

It's encouraging to know that some among us realize the limitations of our knowledge regarding tree biology. Scientific understanding of trees and the role they play in any system is still in its infancy. This is blatantly clear with a simple examination of the body of scientific literature which explores these questions, yet some folks are so convinced that we already know everything. Perhaps because of this, arboriculture will always be considered a "soft science" lacking any real credibility.

As a result of staring this thread I've received PMs from angry treebuzz members who felt I was treading on some sensitive ground. One reads...

"before parroting a bunch of myths and questioning the ethics of the majority of arborists. I don't know what you do for a living but it's clear you know little about trees. Fair warning."

Really? Myths? Come on! I'm happy to be in the minority of arborist on this, if it means I'm with the majority of scientists.

The way I see things here on the buzz some people get hot under the collar, but any time some one asks a question and is willing to read every and any answer that comes along isn't skating on thin ice with hot blades. Everyone knows different things and if you don't know you ask. If this were a bias one sided survey then maybe but it isn't so there should be no reason to get riled up. I also believe Bob and Guy doing a casual seminar in a pub would really find the answers, everyone should be invited and maybe even get a ceu out of it.

 

[KevinS]

[ QUOTE ]
I would consider the removal of dead tissue in a tree to be comparable to washing your hands. I don't think the tree really cares much. The limb is sealed internally typically CODIT and all. While I do not think that the dead tissue is in itself infective to a healthy tree, it most certainly increases the number of wood decaying fungi present in the form of spores. All good unless the tree has it's "skin" broken. You wouldn't want to hang out in the hospital around a high frequency of infectious agents if you have multiple skin breaks (like a burn victim) but it may be doable in a fairly sterile environment.

The tree doesn't care - whatsoever. There has been non productive or damaged shut down limbs WAY before the first commercial arborist got on the scene.

[/ QUOTE ]

I agree. Deadwood removal is pretty much an aesthetics driven facet of our industry in my opinion.

A decent argument could be made on both sides of the issue. The pro-
deadwood removal faction can argue that it reduces the wind sail factor somewhat, reduces fungal, bacterial and insect loads somewhat.

The pro-natural faction can easily argue that leaving deadwood provides structural support to nearby live limbs being buffeted during high wind events. That increased levels of fungi, bacteria and insects stimulates the tree's natural defenses keeping the tree's immune system on its toes so to speak. It can even be reasonably argued that higher weight bearing loads on both limbs and trunks stimulate greater caliper growth in both.

In terms of what's best for the trees themselves? In my opinion, in 95 percent of the cases, the pro-naturalists win the day. The most beautiful trees I've ever seen have always been in their natural settings, deadwood and all. Whereas even a class one pruned tree only holds its beauty for a few years before suckering out and losing its beauty.

The 5 percent of the trees that I feel truly benefit from our interventIons are the split or otherwise structurally deficient trees that we rod or cable back into a degree structural soundness, where otherwise they would die or become compromised much sooner.

Jomoco

'The pro-natural faction can easily argue that leaving deadwood provides structural support to nearby live limbs being buffeted during high wind events.'

If this is true how is it balanced against cadmium rubbing? Crossing and rubbing branches can also offer some support or structure but the rubbing can cause a defect.
I've always been taught crossers and rubbers have got to go, but from a structural stand point if each was reduced to have less sail there would in turn be less rubbing at the defect area and possibly one would encase the other or they would fuse as a graft giving mechanical strength. It would leave smaller wounds farther from the main stem and no big cuts.

What do you think about that?

 

[Daniel]

I do this all of the time at my house when pruning. If there is no collar, or just a hint of one I will leave a stub only to come back later to make my final cut. Other times I do this is when there is little to no chance of the tree occluding the wound. I do feel that it's better for the plant, but while working on a clients tree I also factor in when or if I will becoming back later that year, in three years, or perhaps never if they are selling the property.

Any green cut that would leave a 4" wound on a main trunk or stem, gets a stub.. the bigger the limb, the longer the stub.. Once the reasoning is explained to the homeowner, they come right along 98% of the time. Many of us have come to similar conclusions on our own, the industry and its "minds" are slow to change.. common sense will hopefully prevail where science cannot tread ( unless you got 50+ years to do your research). The problem is that though books and scientific papers are written on trees, they are NOT trees... That perfect target cut is a lot easier to make on paper. The other problem is the human element. Of all the arbs I've worked with over the years, I've only seen one that makes near perfect target cuts. the rest either weren't trained or didn't care enough.

 

[guymayor]

"I've always been taught crossers and rubbers have got to go,..."

"Rules are too absolute for Mother Nature" Shigo

" but from a structural stand point if each was reduced to have less sail there would in turn be less rubbing at the defect area and possibly one would encase the other or they would fuse as a graft giving mechanical strength. It would leave smaller wounds farther from the main stem and no big cuts."

Kevin that's a good example of the need to set aside those 'rules of thumb' that unfortunately are not true, but still are taught. "Inosculation" is the term for 'encasing' or self-grafting.

Dan it's good to avoid 5"+ wounds, but I think you meant "Almost any..." and not an absolute rule.

 

[treehumper]

Maybe a slight change in how we approach the rules is in order. Instead of cut this or remove that, it should read, look for and assess these conditions. What is the objective of accessing the tree vs. objective of pruning. Go up looking for deadwood of a certain size and determine if it needs to be removed or if it can remain. Rubbing limbs? I've left plenty or reduced their weight as the way to attain the objective of mitigating limb failure.

There is a lot of science and research out there that we can access. Because much of it is done in the name of silviculture it takes some additional processing to understand how it applies to arboriculture. How about seeking out some literature to support or validate your opinions? You'd be amazed at what you'll find out there.