Thread: Burls - what causes them???

Aliens, fungal or insect attack.

Especially if there has been damage to that part of the tree.

Often caused by drunken aliens shooten lasers.

You need some aliens.

Think of 'em as a form of skin cancer for trees.

What causes skin cancer in humans? Well... we've got a range of known causes, a range of suspects and, I'd imagine, there are causes we don't know about yet. This has been the subject of many years of study.

AFAIK, far less effort has gone into the matter of burls. We have many suspects: stress, bacteria, insects, fungii and, yes, even aliens playing with our minds. But no-one really knows although everyone has their opinions.

Personally I suspect that a lot of 'em are just petrified echidnas, chased one too many times up a tree... Do you have echidnas in your part of the world? No? See? I rest my case.

Originally Posted by dazzler

Aliens,

Often caused by drunken aliens shooten lasers.

You need some aliens.

I'm seen as one of them - at least that's what is says on my ID card!!! Not being of the indigenous skin colour, this is what were labelled as!
Now where did I put that laser..............

Seriously though - thanks - that's what I thought - we obviously don't have the right insect/fungi - still won't stop me lookin though - never know.

there is a bacterium that causes crown gall but this is not the only cause.

Originally Posted by Skew ChiDAMN!!

AFAIK, far less effort has gone into the matter of burls. We have many suspects: stress, bacteria, insects, fungii and, yes, even aliens playing with our minds. But no-one really knows although everyone has their opinions.

Personally I suspect that a lot of 'em are just petrified echidnas, chased one too many times up a tree... Do you have echidnas in your part of the world? No? See? I rest my case.

Thanks Skew - nope, none of them round here that's for sure, but plenty other 'scared' things runnin up trees!!! Obviously the trees don't last long enough for the burl to form!

the geeks have an idea

http://www.wisegeek.com/what-is-burl-wood.htm


cheers

Originally Posted by dazzler

the geeks have an idea

http://www.wisegeek.com/what-is-burl-wood.htm


cheers

Thanks for the link.

As you can see from the responses, nobody knows.

That shouldn't stop us from opining.

nematoda burlensiata commonly known as the Burly Worm as in "the burly worm catches the bird". and the reason he can do this is that Burly Worms live on steroids found naturally in eucalypts making them big and strong which causes the hump in the tree known as a Burl. True mate.

I think that "burl fairies" cause them.

The trunk of most trees, but especially Euc's are covered by epicormic buds that can sprout to form new branches if conditions are right IE bushfire, physical damage etc.

Sometimes these epicormic buds "misfire" and instead of producing new growth in the form of leaves and stems produce growth in the form of woody tissue. Hence burls...........














I have to admit I just made that all up, but its as good a theory as any.

Originally Posted by Bleedin Thumb

I have to admit I just made that all up, but its as good a theory as any.

No you didn't.

http://www.google.com/search?hl=en&i...picormic+burls



Joe

Seriously though I got this response from my mate at Forestry Tas when someone else asked this or a similar question early last year. Go to the bottom of this post and read emails from the bottom up


To: Steve Rea[
Date: Jan 19 2006 - 8:33pm
Dear Mike

I am not as much an expert in wood anatomy as Tim Wardlaw suggests.
The best descriptions of these phenomena of elliptical defects
(birds-eye, not always caused by dormant buds) and longitudinal waves
(fiddleback) are to be found at
https://www.woodworkforums.com/%3Ca%20href="] http://www.ag.auburn.edu/aaes/commun.../figureinwood/
http://www.ag.auburn.edu/aaes/commun.../figureinwood/
and
https://www.woodworkforums.com/%3Ca%20href="] http://www.hobbithouseinc.com/person...cs/_figure.htm
http://www.hobbithouseinc.com/person...cs/_figure.htm

Hope these prove useful. I have not found more detailed explanations
of the origins of these phenomena.

Regards

Steve Read



Steve Read
Chief Scientist
Forest Research & Development
Forestry Tasmania

Tim Wardlaw 13/01/2006 2:11:10 pm

Gents,
I have sent an interim e-mail to Mike Gard (copy below) but would
appreciate it if you could add your repective expertise.
Thanks,
Tim

Afternoon Mike,
Evan forwarded you question on to me to deal with He mentioned
something about being buried under legal documents so I reckon he would
prefer to be talking about wood grain in eucs than what he is currently
doing.

Your question is outside my field of experetise (pathological
problems including wood decay) so I will forward on to two people in FT
who might be able to give you more info - Rod Hill, who co-ordinates
wood sales and has alot of field experience in developing log
specifications; and Steve Read, our Chief Scientist, who before he
became a research manager worked in wood anatomy at Melbourne Uni.

From my limited experience I believe fiddleback and wavy grain generally are
strongly under genetic influence. Birdseye is a concentration of dormant
buds (epicormic buds). It's very common in burls, which in that case is
an age-related genetic abnormality (much like cancers in people).

However, I don't think birdseye is restricted to burls and may occur as
an abnormality in the main trunk but I am not sure of the factors that
would lead to such development.

Hopefully Rod and Steve might have more info.

Evan Rolley 13/01/2006 11:17:13 am

Tim, Please send Mike you considered reply on my behalf..I am up to my
armpits in legal documents ahead of Mondays action. Thankyou, Evan

Mike

G'day Evan
How're you doing?

Just wondering if you can tell me (or point me to someone who can) what
causes fiddle-back and birdseye grain in eucalypt - or any tree for
that matter?

Is it to do with water supply or is it just an inexplicable quirk of nature?

Cheers
Mike Gard

Thanks very much Steve. Just what I was after.

Cheers

Mike