Reaction wood

[treeseer]

...So on a strictly scientific basis I would say that the paper hasn't proven any universal principles.

Quite so; there are many shadows of doubt, in the open mind.

[jomoco]

Yes, so very many gullible customers, with open wallets...

 

That the ISA now aids them gettin screwed over by charlatans in this biz?

 

Get your Cobra Snake Oil here folks! Only 350 quid a bottle!

 

I hope Cobra and the arborists that promote and install their cabling systems get sued out of business in a court of law.

 

Jomoco

[daltontrees]

I think I may correct the entry in Wikipedia for 'reaction wood' as it is plainly wrong (see attachment in earlier posting). Anybody got any thoughts on this before I do it?

[jomoco]

Buttressing wood formation falls into the reaction wood category IMO. Very old Cal peppers(Schinus molle) and Box elder(Acer negundo) are examples in my neck of the woods.

 

http://aob.oxfordjournals.org/content/85/1/1.full.pdf

 

Go for it Jules. That wiki definition is lame.

 

Jomoco

[daltontrees]

Buttressing wood formation falls into the reaction wood category IMO. Very old Cal peppers(Schinus molle) and Box elder(Acer negundo) are examples in my neck of the woods.

Jomoco

 

That's a really good article but I don't agree with you and here's why. I am not trying to prove or disprove why or how reaction wood forms, I am just trying to dispel some of the bogus definitions. The interrelationship between thigomorphic wood reation wood, negative-geotropically influenced wood, well-nutritioned wood etc. is definitely blurred, overlapping and subject ot any number of poorly understood feedback loops, but ultimately reacton wood is defined as forming to combat gravitational loads. Indeed, your cited article says as much by defining reaction wood as "wood with distinct anatomical characteristics which, in dicotyledonous trees, occurs on the upper sides of branches or leaning trunks in areas subject to tensile stresses (tension wood) and can perform a straightening function."

 

Because butresses and upright butts just aren't branches or leaning stems, they can't have 'reaction wood'. But clearly they can and do exhibit adaptive growth, which your article explains is characterised by increased wood density as well as butress height. However, the increased density could be due to increased lignin to support self-weight of the trees as they get bigger. Elaeocarpus is an angiosperm, and reaction wood in the strictly defined sense should manifest itself as topside cellulose-rich tension wood on branches. I am not seeing how this is comparable to topside (possibly) lignin-rich compression wood on butresses.

 

The whole thing would be simpler if we scrapped the reaction wood distinction and talked of compression-adapted wood and tension-adapted wood. This would take gravity out of the equation and might lead to a better understanding of the mechanisms behind the adaptations.

 

I'll put the kettle on and have another think about it.

Edited April 14, 2014 by daltontrees

[treeseer]

I'll put the kettle on and have another think about it.

Have you read the tea leaves yet?

 

ISA International Society of Arboriculture : compression wood reaction wood in gymnosperms, and some angiosperms, that develops on the underside of branches or leaning trunks and is important in load bearing....

holding wood section of wood located between the face cut and the back cut that helps direct where the tree will fall (see hinge)....

reaction force force of equal magnitude exerted in the opposite direction of a force acting on a body....

reaction wood wood formed in leaning or crooked stems or on lower or upper sides of branches as a means of counteracting the effects of gravity (see compression wood and tension wood)....JUST LIKE WIKIPEDIA!

reaction zone natural boundary formed chemically within a tree to separate damaged wood from existing healthy wood. Important in the process of compartmentalization (contrast with barrier zone)....

soil reaction pH (acidity or alkalinity) of a soil....

summer wood see latewood....

tension wood a form of reaction wood in broadleaved trees (hardwoods) that forms on the upper side of branches or the trunks of leaning trees (contrast with compression wood)...

 

A300 Standard's is better imo: Wood formed in response to mechanical stress or loading. (92.16)

 

It IS externally visible, as when the orange inner bark shows through where there's rapid growth. imo.

 

Nice work on the pdf tho; all that done for fun? Goodness.

[jomoco]

I'm gonna scurry out on a limb here Jules, and agree with Treeseer on this matter, with the proviso that all live wood has the ability to form reaction wood.

 

It's further my belief that localized motion, including vertical splitting are what trigger buttressing wood and burl formation on the trunks of very old and mature hollow trunked Pepper and Box elder trees, to name a few.

 

The vertical cracks found in the outermost bark of so many euc species as part of their natural girth expansion process lends a fair degree of support to my opinion also. Those vertical cracks rarely extend any deeper into the trunk than the cambium layer.

 

After reading your preliminary draft on reaction wood definitions and descriptions?

I was left thinking about it only applying in the weightlessness of space where gravity can't trigger reaction wood to form without some artificial rpm!

 

Hence my opinion that all live wood subjected to gravity is in fact reaction wood, or has the innate ability to form reaction wood when disturbed by a variety gravity related factors.

 

Reminds of that great 70's sci-fi flick about forest pods in deep space, Silent Running.

Starring Bruce Dern as the dedicated caretaker of the last of earth's forests in transit.

 

Jomoco

[treeseer]

Shigo 1986: "Wood altered as a result of a lean...(1/2 page of forestry stuff)..."

 

pretty narrow.

[daltontrees]

Have you read the tea leaves yet?

 

reaction wood wood formed in leaning or crooked stems or on lower or upper sides of branches as a means of counteracting the effects of gravity (see compression wood and tension wood)....JUST LIKE WIKIPEDIA!

 

Not so. Wikipedia says "Reaction wood forms when part of a woody plant is subjected to mechanical stress, and helps to bring parts of the plant into an optimal position. This stress may be the result of gravity, wind exposure, snow buildup, soil movement, etc. "

 

This is closer to the definition of adaptive growth. The point Im trying to get across is that all the reliable definitions (including ISA, thanks for that) say it's a response to gravity on leaning stems or limbs.

 

At least that's what the tea leaves are telling me. Maybe I've had too much tea. And yes, it's all being researched in the interests of , well maybe not fun but the satisfaction of furthering better understanding. Wikipedia's great a lot of the time, I use it daily for various things, but the quality is a bit variable. The reaction wood definition is definitely wrongly cited and syntactically wrong and also is wrong. 3 wrongs don't make a right.

[daltontrees]

Jomoco, I am pleased to have anyone pitching in. Sometimes I noticve that hundreds of people have read this thread since a couple of days ago yet only a few (mainly from USA?) bother to comment.

 

We are not disagreeing. I agree entirely that all wood has the pre-disposition to react to all sorts of circumstances. I also agree stresses can be mechanical (flexure) or gravitational (weight) or intermittent loading (snow or foliage). Or bits of all 3 at once. Hence my comment to treeseer that 'all wood is interaction wood'.

 

I'm just saying that the words 'reacton wood' have alredy been defined by others to be restricted to situations of gravitational forces. We may need another term for flexure wood, but trying to lump it in with reaction wood won't help.

 

To pout it another way, if reaction wood is as Lonsdale purports explicable by gravitational relocation of growth-inducing auxin, then butress wood cannot be reaction wood. There may be another mechanism, at cellular level, that is triggering the production of wood of particular quantity and/or quality where there are regular flexure stresses at the base of an upright tree.