Which is also pretty much what I figured you meant.
Reaction Wood
- Thread starter oceans
- Start date
evo
Been here much more than a while
- Location
- My Island, WA
My observations based on looking at the growth rings of conifers has me thinking trees are well adapted to alter their reaction wood growth. Subtle pruning on the right or left can have observable changes in the rings. Also adjacent limb removal/failures or neighboring tree removal can have profound effects. Same with snow loads etc.
I have been told that once reaction wood is triggered, the plant doesn’t stop putting it on in that area. I’ve questioned this at times but I think of it differently than tension and compression wood as an independent type of response growth.
Such as tension wood and compression wood are only one type of reaction wood, and that there is more at play than gravitational effects. Is there no torsional reaction wood? We have all observed spiral grain, is this not reactive?
I don’t trip on this, for these reasons and if one does reduction pruning evenly and thoughtfully stress/loading should be reduced uniformly along that part. I have seen failures as a direct result of ‘unbalanced’ reduction cuts, resulting in torsional failures. Dosage and size of cuts are commonly drilled into our standards these days, however what is lacking is the finer details of the placement of these cuts to provide uniform reduction of load input forces.
One must consider the old wind load physics of creasing a piece of paper in a 45 degree fold and blowing across the apex of the bend. The lesson as it applies to pruning is that there are so many dynamics with wind one must consider the windward side as well as the leeward side.
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Matias
Been here much more than a while
- Location
- Butte County
I cringe when a customer starts asking me to take off all the danglers. I explain this pretty much exactly to them and proceed.
evo
Been here much more than a while
- Location
- My Island, WA
There is a time and place for this. Never forget a ‘pretty’ tree is a respected tree. The goal of the customer might be to make the tree pretty, and getting the stuff drooping lower than horizontal can increase airflow and light to interior shade leaves avoiding the their shedding due to too much shade (and providing future retrenchment locations).
Remember Auxin is a gravity fed hormone, and it is reduced in limbs ~45 degrees to horizontal and it doesn’t flow uphill lower than horizontal. So in most species the vigor is lost below horizontal.
I was taught crown cleaning to include the 3 d’s with a eye for unproductive, air circulation, and growth direction.
ATH
Been here much more than a while
- Location
- Findlay, Ohio
I've told a lot of clients who say "I just want what is best for the tree..." that "The best thing for the tree is that you love it! We'll take proper care of it, but if a small limb here or there that isn't going to make a difference to the tree makes a difference to you, we want to either leave or take it depending on your vision of the tree, so I want to hear your preferences too!"
Subtle nuance is surely the case in every case. I agree there are a myriad of factors that inform our pruning decisions. Believe me, I deliberate reductions extensively, and change my scope from narrow to wide during those deliberations. Look at the lead, imagine the change, look at the greater view of the surrounding elements, look back at the lead, reimagine, re-evaluate…finally, cut. Or not.
Any cross sectional cut, or longitudinal cut (milling) can expose all sorts of interesting things. Ring shake is one thing that I can imagine we (or nature) could create by suddenly and drastically altering reaction wood somewhere along the tree’s lifespan.
Same
Matias
Been here much more than a while
- Location
- Butte County
I definitely don't have many hard rules, and do talk about options and style with the client first. The danglers I am thinking of are often the majority of what a particular branch has become after many years. I will start to get some more before and afters, which I want more of for my portfolio anyway, and start a thread. Like a "rate my prune" thread. I am always curious what someone else might have done differently, as so many of our choices are guided by experience.
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That’s a GREAT idea. Probably going to have to include what the client’s goals were as well to bolster your decisions in the Appropriate Response Process.
Steve Connally
Been here much more than a while
- Location
- Suffolk, Virginia
No apologies necessary. I appreciate the considerate and thorough response. I'm not pushing back at you at all. I appreciate your insight. I just think it's an interesting conversation and I'm trying to understand others viewpoints. Perhaps a thread on Epistemology.
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KTSmith
Branched out member
- Location
- Maine, New Hampshire
Oooh, that's the branch of philosophy that could use more explicit understanding, both in arboriculture and in everything else! How do we know what we know? No way that that would go off the rails!
Steve Connally
Been here much more than a while
- Location
- Suffolk, Virginia
Exactly. Again, thank you. I feel sad often when I look at how we a humans communicate with each other of late. The ability to look at another objectively with understanding is substituted with rage and instant antagonism. Half the time I don't comment because of how the other person might misinterpret what I say. I am just curious why I shouldn't say I've researched a subject. Perhaps I should say I've read extensively and feel like I understand. IDK. The world has changed. I have changed, and I don't like it. Thank you
pete3d
Participating member
- Location
- Hinchinbrooke
Although they say rules are made to be broken:
People do get safe home each day ‘cause they nearly always “follow the rules” - they look both ways before crossing the street, they look behind before they backup, they don’t say derogatory things about the policeman’s mother when asked for their car registration.
As arborists, we keep living with most of our limbs intact by doing the same - putting the break on a running chain saw when dancing about with it, wearing the appropriate PPE, tying, setting, dressing and inspecting our knots etc. etc.
I think people could live “safer” or at least less stressful lives if they followed the most basic social rules. Here’s a good one that my mother always told me, “If you can’t say something nice, don’t say anything at all.”
Though I fully understand what Tom is trying to convey with his statement on 'research' and I loved Kevin's excellent definition of what 'research' means to an actual researcher with thousands of field work hours under his belt, the word 'research' can also be used, accurately, in a less regimented way.
People use reading for research every day.
...she spent hours reading all she could find on the colleges that would best meet her needs.
...he poured through dozens of spec sheets looking for an appropriate computer screen for his setup.
... the homework assignment was to find examples of the impact agriculture had on human populations.
I could go on and on but the point should be obvious. Tons of things can and are researched through reading and doing so does not diminish the information gained.
Matias
Been here much more than a while
- Location
- Butte County
evo
Been here much more than a while
- Location
- My Island, WA
Your ring shake theory would be an interesting research topic! See what I did there?
My take on ring shakes is it’s more of a wall 4 thing vs delamination along the ring? I do see checking and cracking in wood with heavy reaction wood. Alders do this nearly all the time, you can feel it on a removal with limb weight being removed. When I comes to the spar and blowing the top you will feel a pop violently enough to shake sawdust accumulation off the moss. It’s wild to look at a fresh cut on the spar and a neutral plane crack suddenly appears. I’d say ‘watch’ but there is nothing to watch, it just is instantly there where it wasn’t before.
southsoundtree
Been here much more than a while
- Location
- Olympia, WA
I find that 'pop' much more in bigleaf maples.
Alders, too.
Might be that I dismantle more maples than alders.
Alders, too.
Might be that I dismantle more maples than alders.
Similarly, I felled a 24” Norway Maple this Summer. I would not have guessed there was much reaction wood in the trunk based on its overall crown balance over a relatively straight trunk. No sooner did the crown hit the ground, I hopped up on the stump. A moment later I heard a pop which I also felt in my feet…the stump split in two, but nothing happened to the trunk. Hmm.
evo
Been here much more than a while
- Location
- My Island, WA
I’ve heard of doing experiments in tension and compression wood. Unfortunately I cannot recall any of the the specifics on what the were actually testing.
Vertical kurfs were sawn fairly shallow and ball end sewing pins were placed and measurements over time were taken. I want to say the top side kurfs opened on conifers and closed on hardwoods, and the opposite with the under side. (Maybe backwards?)
Similarly the pins were placed from the growing tips down the stem and then measured for cell elongation.
This was so long ago it might even be second hand meaning it was someone telling me about this.
It would be interesting to either research this finding the study, OR much more fun if a group of us collaborated, open source sharing our findings across different species over x number of years. Even cooler would be figuring out how to bend trees of x diameter x height, and measuring when and where the response growth occurs.
Writing this out it would be interesting to discuss if there is a distinction between RESPONSE growth, and REACTION growth. I recall when reaction and wound wood were considered the same. Could there be a difference in the type of response? Growth response (gravitropic, phototropic), and reaction wood (sudden weight shifts, sudden event/leans/callus)?!
Vertical kurfs were sawn fairly shallow and ball end sewing pins were placed and measurements over time were taken. I want to say the top side kurfs opened on conifers and closed on hardwoods, and the opposite with the under side. (Maybe backwards?)
Similarly the pins were placed from the growing tips down the stem and then measured for cell elongation.
This was so long ago it might even be second hand meaning it was someone telling me about this.
It would be interesting to either research this finding the study, OR much more fun if a group of us collaborated, open source sharing our findings across different species over x number of years. Even cooler would be figuring out how to bend trees of x diameter x height, and measuring when and where the response growth occurs.
Writing this out it would be interesting to discuss if there is a distinction between RESPONSE growth, and REACTION growth. I recall when reaction and wound wood were considered the same. Could there be a difference in the type of response? Growth response (gravitropic, phototropic), and reaction wood (sudden weight shifts, sudden event/leans/callus)?!
