Causes of spidering

Sawyerfortyish · February 11, 2006, 07:35:59 PM

I know what causes windshake. But what causes spidering in a butt log of a tree?I got in a huge oak in the mill it was 12' long. I cut it down to 8' but the spidering is still so bad I don't think I can even get good blocking out of it. The fishers in the log run almost to the end of the log. A guy came in for lumber and asked me what caused it in the piece I cut off and I couldn't give him an honest answer.

rebocardo · February 12, 2006, 12:53:08 AM

Well, I think maybe the tree has been blown over. I noticed when I use to mill my tree jobs that if it had been blown over maybe 50% would have a spider like effect. I think laying on the ground for any period of time makes it worse, even if it is not bucked and still attached to the root ball.

Worse, on one job it would not start cracking until after a board was cut. Then it would fall apart when you tossed it onto the pile. Last one I had like that was red oak and I just gave up and made the whole tree firewood.

extrapolate85 · February 12, 2006, 01:21:20 AM

I think it is caused by frozen wet-wood.

Sawyerfortyish · February 12, 2006, 07:31:27 AM

If it's caused by frozen wet wood how come every tree doesn't have it. I think a tree that is spidered has a diesease. Much like wind shake where a diesease weakens the wood fiber and allows the wind to seperate the grain of a tree. I see spidering in a lot of trees standing in the woods. I never gave it much thought about how that tree got that way.

Tom · February 12, 2006, 09:28:21 AM

What is spidering? I'm not familiar with the term. Do you have a picture?

If you mean that the wood is falling apart (shattered) inside, I've found that the reason is generally shock. Trees that have been pushed over by bulldozers, pulled by winches, dropped across other logs, etc., suffer from shattering. Sometimes lightening will cause it too, but that damage is usually higher up and can generally be diagnosed from the outside of the tree.

wiam · February 12, 2006, 10:05:37 AM

I have heard that shake has nothing to do with wind, just disease.

Will

David_c · February 12, 2006, 11:03:59 AM

Here you go Tom. Wish I could get it come out bigger.

Cedarman · February 12, 2006, 11:52:35 AM

That picture says it all. Now I know what spidering is. We call it frost cracks. I am not sure I have read the definitive cause though.

Black_Bear · February 12, 2006, 12:06:50 PM

A frozen tree that is violently rocked by the wind may experience a separation of the annual growth rings.

The shake you are probably accustomed to in hemlock, and sometimes red oak in northern Vermont, is caused by anaerobic bacteria, which often moves up from the roots.

Most loggers realize that stem and crown damage need to be avoided. That is true. What they don't realize (and I never really did when I was cutting wood) was that root damage is the conduit that allows many forms of bacteria and fungi to access the tree. Often times the root damage goes unnoticed. Out of sight, out of mind.

Don P · February 12, 2006, 12:26:24 PM

And to go back to Extrapolate's response, we often call that bacterially infected wood "wet-wood". I've always thought it was from frozen wetwood too but am not sure.

beenthere · February 12, 2006, 01:17:06 PM

Growth stresses in the tree which affects some species more than others, may be what is behind the 'spidering' end checks. Here is an interesting article discussing these growth stresses.

Growth stress in trees

Cedarman · February 12, 2006, 03:20:24 PM

We see it in ERC also. Usually only in the butt log. The logs are unusually heavy, have a black appearance at the butt end. When sawn the boards have lots of cracking, especially toward the center. Also, I don't remember it being associated with rot. The wood is usually red heartwood not subject to fungal rot, but is very shaky in appearance. When the boards dry out the darkness disappears. At first glance the boards look ok, but when cut in short lengths they fall apart.

SwampDonkey · February 12, 2006, 04:53:45 PM

Shake in eastern hemlock, at least up where I'm at, is caused by sap sucker damage over several years of the tree's development. I don't know of a single hemlock around here that isn't pecked by sap sucker. The wood is usually left standing or to rot on the ground. There is a market for hemlock, but the price is pretty pathetic and probably due to shake. Now, there is nothing to say that a fungus isn't infecting the injured tree, in fact it is most likely there is a fungal infection. However, I'm not familiar with the possible diseases or mode of transport into the tree wood.

I sawed up a pin cherry once and stacked it into a firewood pile. In no time the wood separated at the annual rings like an onion pealing. Pretty useless wood unless dried and under cover. I cut one for a friend who had it sawed and he made some things from it. (jewlery boxes and such) ;)

rebocardo · February 12, 2006, 05:07:53 PM

That star type pattern is what I mean by spidering.

Sawyerfortyish · February 12, 2006, 06:21:24 PM

Usally the trees that are spidered have cracks or fishers running up the the log from the ground and can be bleeding out water or sap. Sometimes if you cut them high and then take a butt cut off you can get rid of all or most of the spidering. A lot of times after you cut off the first 8-10' the rest of the tree is fine.
Rebocardo that star pattern is exactly what i'm talking about just like the pictures.

WH_Conley · February 12, 2006, 06:30:12 PM

I cut a red oak a few days ago that the chain locked up on the saw, looked down and water was running out of the cut, with sawdust. Finally got everything freed up and when I got the tree on the ground found that the log had cracks like a star or spider running from the pith. They just went out a little way, not like I have always associated with freeze crack which I always thought went from the heart to the bark. I might be wrong on this, if so, I will be glad for the education.
Also there was no external sign to show anything wrong with this tree.

Kevin · February 12, 2006, 07:45:35 PM

Red Oak sawdust is bad for jamming up a chain unless you clear it.

Black_Bear · February 12, 2006, 09:05:06 PM

I guess I was wrong about the causes of ring shake earlier and I probably should have realized it. If I would have read the rest of my notes I would have read that the wind theory is unproven, but still thought to occur by some wood scientists.

I felt really stupid so I went and dug out an article I printed out last year. The article cites the work of Alex Shigo back in the 1960s and states that he did indeed find a high correlation between sapsucker damage and ring shake.

The internal stress theory goes back to the 1930s and has been proven more than once.

The article is on the web here:

http://www.fs.fed.us/na/morgantown/hemlock_proceedings/p156.pdf

I found this article while I was doing a report on tree pests last year. The hemlock proceedings in which this report originated from had some good literature on hemlock woolly adelgid.