tree terminology

[murphy4trees]

I have been using the terms "compression wood" and "tension wood" to refer to parts of a hinge in a side leaning tree... or called the underside of a limb, compression wood and the top, tension wood..
I was told by an authority that I should replace these terms with "wood under compression" and "wood under tension", because deciduous wood is compression wood and conifer wood is tension wood (or vice versa).

Now as Rocky says..."I may be just a dumb tree cutter", but I never heard that before and it makes no sense to me..

So does anyone know? I checked in Beranek and Dent and didn't actually see the terms used, but I believe I have seen them used in some on line piece.... Maybe the OSHA logging pages

Thanks

 

[Lumberjack]

I thought that hardwoods were tension, but I am not sure.

If you are talking about hinges, then the type of the tree isnt as important, so i say keep it. No point in fixin it if it aint broke.

 

[Nickrosis]

You're on the cutting edge! They're flexible terms because we're still learning a lot about reaction wood. The traditional thinking is that compression wood is only found in conifers and that tension wood is only found in deciduous trees. I say traditional because you can disect up a tree and find reaction wood in the "wrong" trees!

It's better to think of conifers tending to produce compression wood, because that's what usually happens. But it can also form tension wood. Vice versa with deciduous trees and tension wood.

Essentially, both are effective ways of holding a stem up, but each has a preference. Don't look in books, like netree would say. Dig up some tree roots and cut cross-sections of branches or leaners, and you'll probably see this taking place.

 

[Stumper]

Those terms DO NOT denote deciduous or evergreen. All limbs have tension/compression wood and so do trunks with heavy leans. Tension wood forms on the upper side of the stem, compression on the bottom. The fact that this tissue is laid down in response to strain causes it to have differing properties. Look at the growth rings on an old leaner. Growth rings tend to be broad on the upper/tension side and narrow on the lower/compression side. Those different widths are indicative of differing densities. This type of wood does funky things when milled and then allowed to dry. It is also called Reaction wood[/I]-because it forms in reaction to stresses and because removing it from the surrounding tissue gets some strange reactions. this is all part of the way wood forms and is A.interesting and B. normal. Your usage of tension /compression wood has always been understandable. Personally I prefer to refer to tension and compression fibers.:angel:

 

[Stumper]

Good post Nick. You have faster fingers than I.

 

[NeTree]

Even more fun is when you can look at a stump, and tell which way the tree was leaning (if it was), what time of year it was cut, and how long ago. Shigo would be proud!

 

[Nickrosis]

Did that answer your question, Daniel?

 

[murphy4trees]

Yes,
Thanks to all...

 

[John Paul Sanborn]

Get Mattheck's book "body language..."' he goes into detail on this subject.

whath you will find is more compression the more latereal the branch and the tension on the more vertical.

IMO we find comression on conifers more, because they are more spreading. An aspect of geotropism?

 

[Gypo Logger]

Of any tree I have ever witnessed, I would say the Spruce is the toughest tree known to man, and is the most forgiving or unforgiving, depending on how you look at it.
Spruce can be compressed so much, by say frozen rain that the leader can touch the ground and spring back to it's original form when the air warms again.
In fact, Spruce is so tough, that I noticed when cutting a row of them, I tried to commit one over with a 16,000# skidder with 30% holding wood and a clean knotch and backcut, that the skidder simply climbed the 10" Spruce till the rearend of the skidder was off the ground and the tree was at a 35* angle.
Now that's pretty darn tough!
John