Dead (and Undead) Wood

[moss]

Always and never, are concepts best left to other discussions.

I really like this, whenever those words are used they are usually (not always) wrong.
-AJ

 

[evo]

Just a reminder that some species such as oak and sycamore will form a "collar" of woundwood on long dead limbs far further out from the stem then we are often taught take our cuts.

Food for thought

We have a few that do the same here, and then also some species that rarely have collars. Once the limb dies or starts declining the collar will start forming.
This well a different thing happens sometimes with Douglas fir. It’s neither epicormic nor the collar expanding outwards. But I see it most often with ~3” diameter broken limbs with decent sun exposure. The limb will break clean off, at the natural fracture zone, and still callus or the break a foot or more away from the stem, not a single needle on the stub.
I can only explain this by there is enough photosynthesis going on with the cambium, it still can make it’s own wood.
However it also might be a reversal in the direction wood is put on, like the root grafted stumps callusing over. Likely much more going on there than we have wrapped out brains around.

I’m realizing we need to further define what we are talking about with ‘deadwood’. For me I’m talking about naturally shaded out or naturally broken/shed. Not a co-dom/tear out nor a injury to the main trunk.

In PNW conifer land the only pathogenic fungi I’m aware of that either erupts or infects dead stubs is Pini, and some weird kind of yeasty thing on hemlock. Still not conclusive if it’s a niche environment and the crud is just fruiting at these points, or if it’s a infection arising from these points.

 

[moss]

We have a few that do the same here, and then also some species that rarely have collars. Once the limb dies or starts declining the collar will start forming.
This well a different thing happens sometimes with Douglas fir. It’s neither epicormic nor the collar expanding outwards. But I see it most often with ~3” diameter broken limbs with decent sun exposure. The limb will break clean off, at the natural fracture zone, and still callus or the break a foot or more away from the stem, not a single needle on the stub.
I can only explain this by there is enough photosynthesis going on with the cambium, it still can make it’s own wood.
However it also might be a reversal in the direction wood is put on, like the root grafted stumps callusing over. Likely much more going on there than we have wrapped out brains around.

I’m realizing we need to further define what we are talking about with ‘deadwood’. For me I’m talking about naturally shaded out or naturally broken/shed. Not a co-dom/tear out nor a injury to the main trunk.

In PNW conifer land the only pathogenic fungi I’m aware of that either erupts or infects dead stubs is Pini, and some weird kind of yeasty thing on hemlock. Still not conclusive if it’s a niche environment and the crud is just fruiting at these points, or if it’s a infection arising from these points.

Tom Wessels who is the well-known northeast U.S. "forensic ecologist" has documented the same "stub behavior" on Eastern Hemlock, to the extreme where a completely decapitated hemlock grows tissue over the remaining "ground stub" and continues living, zero foliage. Super interesting. It may have to do with the remains of the tree leveraging the root zone mycorrhizal network, essentially being fed what it needs in its extreme "idling" state by surrounding hemlocks. Trees are cool.

@Tom Dunlap can this thread be renamed "Dead and Undead Wood" ;-)
-AJ

 

[moss]

We have a few that do the same here, and then also some species that rarely have collars. Once the limb dies or starts declining the collar will start forming.

This is super interesting as well, I'd been wondering about this for red oak family species. What are the details of the biological triggers, timing and processes for starting collar growth on a declining limb? As Evo indicates it could be very different per family, genus, and potentially species. Not to mention the vast differences between conifers and broadleafs in general.
-AJ

 

[moss]

For red oak family trees I've been noticing existing systemic fungi seems to speed up or even initiate abscission processes for twigs, branches and limbs. Especially following several years of stress conditions like extreme drought alternating with extreme wet weather conditions. Kind of the classic distressed tree putting out a lot of epicormic growth and then cutting it off resulting in chronic twig and small branch showers. Rinse and repeat, tree keeps going but in a losing game.
-AJ

 

[DSMc]

... I’m realizing we need to further define what we are talking about with ‘deadwood’. For me I’m talking about naturally shaded out or naturally broken/shed. Not a co-dom/tear out nor a injury to the main trunk...

Dang, I hope I didn't add confusion by posting the picture series of the Tilia americana. The co-dom/tear out was just a reference shot, and the reason why I was there. It was the showing of interconnected columns of decay resulting from retained dead limbs, which riddled the tree, that was my intention to highlight.

 

[moss]

Dang, I hope I didn't add confusion by posting the picture series of the Tilia americana. The co-dom/tear out was just a reference shot, and the reason why I was there. It was the showing of interconnected columns of decay resulting from retained dead limbs, which riddled the tree, that was my intention to highlight.

Tilia seems like it would be higher on the deadwood/decay column list right? Being relatively soft wood etc. In far eastern Mass. where I am it's mostly European origin tilia planted along city and town streets, I rarely work on it. American Basswood is uncommon in my immediate area, soil type is wrong (too acid). Going further west in Mass. soils get sweeter and a lot more basswood, mostly as a forest tree but likely on the edges of people's wooded yards so tree workers there are probably seeing plenty of it and have something to say about its qualities re: deadwood.
-AJ

 

[moss]

Loving the "very not bad" edit to the thread title! Thx Buzzer Mod Gods!
-AJ

 

[moss]

Dang, I hope I didn't add confusion by posting the picture series of the Tilia americana. The co-dom/tear out was just a reference shot, and the reason why I was there. It was the showing of interconnected columns of decay resulting from retained dead limbs, which riddled the tree, that was my intention to highlight.

Ha! No worries, I saw the signature codom "ears" on the remaining leader but didn't make much of it "Just happened to be in the photo!"
-AJ

 

[DSMc]

Tilia seems like it would be higher on the deadwood/decay column list right?...

Very true, AJ. The thing is though, if you look, many different species will exhibit similar decay columns and from the same cause, dead wood. It is also true that some tree species have phenomenal decay resistance. We all know this, right?

So why not just tell it like it is. Yes, some trees will have a net benefit from deadwood removal. It is not a worthless, just-for-profit procedure.

The flip side of the OPs question is, does deadwood improve the health of an individual tree by leaving it on?

 

[moss]

The flip side of the OPs question is, does deadwood improve the health of an individual tree by leaving it on?

Great! In a natural forest context, deadwood is providing a lot of ecosystem benefits so of course what trees do naturally anyway is good enough for the tree. Landscape/property trees of course have different considerations. There is room for tree professionals to advise on wildlife and overall habitat/system benefits for trees that are not over targets or are not “showcase” front yard trees or the equivalent in public spaces etc.
-AJ

 

[DSMc]

I believe this has already been discussed, many pages ago. The OP was not asking the question in regards to ecosystems or forest health. Instead it was directed at individual trees.

 

[moss]

It is one of my gripes with the mostly excellent Arnold Arboretum in Boston, Massachusetts. Majority of the broadleafs are so heavily dead-wooded that it nearly sterilizes (overstatement I know) the overall canopy. In combination with the intensive ground maintenance there is noticeably less diversity for native bird canopy dwellers. And that will also include effects on insect, fungi and even lichen diversity. I’ve observed the place nearly daily over 35 years, it used to be rougher on the edges, more benign neglect but these days they are maxing it out with new plantings and overall land management. I digress but the lack of retained deadwood is striking.
-AJ

 

[moss]

I believe this has already been discussed, many pages ago. The OP was not asking the question in regards to ecosystems or forest health. Instead it was directed at individual trees.

Yep, epic thread, things will keep coming around.

 

[ATH]

.....Customers are often confused when they say, "Looks beautiful, my tree is so much healthier now, thank you!" and I reply, "Tree doesn't care, its health is not changed but you have a lot less yard clean-up work for a few years". If they want to know more I tell them more, referring them to look at mature broadleaf trees in the forest and their beautiful (wabi-sabi) displays of retained deadwood structures lower in their crowns.
-AJ

I often tell people:
"The best thing for your tree is that you love it!"

If that means cleaning out some dead wood and getting it off of their house and driveway (obviously to the point we aren't detrimental to the tree!). Again, obviously, people need to have a little knowledge/understanding who to hire beyond passion for the tree...but it is a catch phrase. Don't make too much of it!

 

[Daniel]

Tom Dunlap said:
Here's an anecdotal story about this topic. Since the results would be impossible to replicate you have to decide how credible the outcome is.

A compan that I know had a client with a large American elm that was infested with a number of critters including fungus, bugs etc. that were weakening the tree. IN order to keep the nasties at bay a very involved and expensive chemical treatment and fertilizer program had been followed for several years. The tree had improved just a little but the client was concerned about the expenses. The arborist suggested a VERY thorough deadwooding down to pencil and matchstick diameter. This trim job wasn't cheap either.

Over the next couple of growing seasons the arborist tracked what the tree needed to keep the nasties at bay. What was found was that the costs for treatment plummeted and the tree improved. The variable was the thorough deadwooding so the conclusion was that the pathogens had deadwood to 'eat' and openings into the tree for exploitation. The tree does expend energy isolating deadwood and trying to grow over stubs. With that energy left and reallocated to growth the tree seemed to be in better shape.

It would be nice to read about peer reviewed research about this.

ICAN out of Evergreen College in Washington would likely be a resource. At one time I had a subscription to 'The dead wood Journal' which highlighted research into the topic as it related to forests.





Tom,
It's been clear to me that a thorough dead-wooding of pin oaks with bacterial leaf scorch seems to extend the life of the trees indefinitely and retards the spread of the disease. I pruned several trees many years ago that I thought would succumb in a few more years, yet the trees have flourished in a remarkable way.

 

[Daniel]

The article in question was billed as "scientifically" addressing whether removing deadwood had health benefits for the tree.

A snap shot in time of cladoptosis in limbs in no way provides information on long-term outcomes.

in tree time the concept of long-term outcomes in tree work would take generations. Tree time is measured in decades and centuries, not years.

 

[Tom Dunlap]

in tree time the concept of long-term outcomes in tree work would take generations. Tree time is measured in decades and centuries, not years.

Tree time is species dependant. Aspen tree time can sometimes be measured in weeks it seems. Sequoia in millenium

 

[TreeVB]

It has been a while since I read through this thread and there seems to be great points on both sides of it. Something that I feel is missed is the lack of attention to wall 1,2, and 3 of CODOT. Sure wall 4 is strong and very important, but if we completely trust CODIT then wall 1,2, and 3 should be sufficient to stop protruding pathogens. Wall 4 might happen slower than usual but the natural bandaid “should” help make up for that time.

 

[KTSmith]

Respectfully, I'm not sure what TreeVB means with respect to "completely trust CODIT". CODIT is a model for the concerted set of processes within the wood of living trees to resist the spread of the effects of injury and infection. Yep, some tree species invest a lot in compartmentalization, some not so much. And a starved individual tree may not perform as well as expected for the species in good health. Indeed, the CODIT walls buy time to restore lost sapwood function and the continuity of the vascular cambium. All trees die, all wood rots (in the greater conceptual fullness).
I do trust that CODIT provides a lot of explaining power. We don't know how all of the components work moment-to-moment, and there is species/environmental variation. But the relative strengths of W1-4 are pretty clear for most cases. Part of the challenge in teaching compartmentalization and CODIT is that Shigo used gross anatomical features for largely symplastic processes. If anyone is still reading, the sort-of-recent article by Hugh Morris is a pretty good treatment to which I provided a published commentary here. Apologies, I've probably posted this before in TB, maybe even this thread!