Looking to get some pics to settle a friend to friend dispute (friendly wager).
Just search on google images they have a few pics. Basically its just a separation of the growth rings I believe mostly cause by the freezing process. So whats the wager? tc
Caused by bacteria.
and sapsuckers :D
USDA FS NE RP 21
"Anatomy of hemlock ring shake associated with sapsucker injury" / By Jorgensen, Richard N. / Published 1964
The log we were looking at had red marks in it but no seperation and I bet a night on the town on me if what we were looking at was not shake. Log had already gone to the mill so I was hoping to get a picture to show him it wasn't shake.
Were the red/purplish areas at the ends of the growth rings? Because the late-wood portion of the ring often has a roseate or reddish brown tinge to it and individual rings can be sinuate (wavy) and not uniform in width. This is natural and not shake.
This is an extreme example of shake. Tree was at least 75 yeras old.
(https://forestryforum.com/gallery/albums/userpics/10436/thecfarm14.jpg)
The straight mark down the middle was done by a chainsaw.Too big for pulp. The way you are talking the piece in question went for pulp.?If it went to a sawmill it will show up on the scale slip as a defeat.
Quote from: Ron Wenrich on September 17, 2010, 08:44:08 PM
Caused by bacteria.
Sapsucker damage causing it I have heard of but not bacteria. I believe at the very least moisture and freezing compounds it and is what ultimately results in logs that have no value for lumber. I cut big Hemlock for a couple of years here on the Menominee Reservation. There were tracts in which there was nothing but huge areas of big old Hemlock lots of it was taking a beating from the bugs. I can remember making decks of nothing but the oversize butts that had to be split into 1/4s' so they could go as pulp. Probably some of the biggest wood I have ever cut but it sure can be nasty stuff when it is heavy with shake.
I've never seen an eastern hemlock in NB that didn't have sapsucker injury when it got to be pole size or bigger. We have a lot of them buzzards around here.
Well, we didn't get docked for it. It was just like what swampdonkey described. Looks like it will be a good night out next Saturday for me.
What I've come to understand of the sapsucker caused shake is traumatic resin ducts form which cause a week point. Then fibres separate near the end of the growth ring. I have also heard other forms result from frost-damage zones, and for sure wind action. Those are documented in the literature on wood science. They note that crack formation begins to occur in the densest material, the late-wood.
I doubt if any bacteria could get into those sapsucker wounds. Just a thought.
Here's a discussion on shake:
http://www.woodweb.com/knowledge_base/Causes_of_Shake.html
Ron, I wouldn't be able to say one way or the other. I wasn't linking bacteria so much with the sap sucker injury, just that sapsucker was another cause. But, if an insect can transfer a disease in saliva to say beech, I would not rule out any possibility of something nasty on the beak of a bird being spread about. :D The idea of bacteria seems to be something in recent years, not sure how well that is excepted by the experts. Any documented reports a man can get their hands on? Our hemlock grow in hardwood here for the most part and the red spruce we get wind shake in are also on hardwood ridges, red spruce don't like wet too well unless they cross with black. Even if they are not in hardwood they (saplings) grow on igneous sedimentary very porous soil here by the thousands per acre (we thin it).