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Melvin - ring-barking is still standard practice for Japanese temple builders!

I sometimes wonder if forestry traditions aren't quite pragmatic - at a time when all timber had to be dragged by humans or horses, it was handy to lose some weight by getting a lot of the drying done before you felled the tree. Then if you brought it out it when there was snow on the ground, it was so much easier to haul.

On Stobo Estate (where I used to have a small sawmill), there were various remnants of old horse-drawn sleds which were used for timber extraction until about 30 years ago.

Martin,

Thanks for your post above. I was not aware re Japanese temple builders using this method....I hope to talk to some of these guys about this during next visit to the inlaws there.

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"Some people have speculated that wood cut in the fall and winter should weigh less, since the “sap is in the ground.” However, the water content of wood is roughly the same year-round."...University of Tennessee, College of Agriculture and Natural Resources

I feel sorry for their graduates!

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I feel sorry for their graduates!

Forests cover upwards of 50% of Tennessee. About 96% of the forested land is described as being used for commercial logging, and about 85% of that is privately owned.

95 percent of what is harvested is hardwoods, and the total lumber production in 2002 was 899 million board feet. Your search results may vary.

If you are in a decent position to take issue with the University of Tennessee, please state your case.

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Nate,

Will you describe this color change, please?

Joe

Joe , the color of the maple will lighten from a slightly pink shade when first sawed to a whiter shade as the surface drys .Pretty much the same as the difference you'd get by wiping a little water on a dry board It's quite easy to see as you do it and when there is no further change you're done and should stop the forced air flow. As to my senternce structure if you type as slowly as I do it behooves one to eschew verbosity.

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Just finished reading the rest of this rather excellent discussion . As one of my fellow New Englanders points out there seems to be some confusion about the difference between sap and water in the tree. The heartwood of a tree is basically dead cells and while it still contains moisture there is very little metabolic activity. There is a bit more in the sapwood I think but the sap is almost exclusively contained in the cambium and phloem layers directly under the bark. This is the area where growth is occuring and where sugars and starches are being used for cell construction. Since this entire area will be removed as the log is processed it has little effect on the final product as used in violinmaking." Ring barking" as has been mentioned will gain a head start on drying by preventing some of the moisture take up from the roots but the same thing can be accomplished by leaving the entire tree on the ground for a few days with the leaves still on which sucks water out of the tree so rapidly that the small twigs will be brittle in a short time and the tree can then be processed. I have less experience wiyh drying spruce but think it must be quite different because in soft woods there are resin ducts contained within the wood itself. I beleive that ring barking in softwoods might result in a reduction of resin content and I would be interested to hear from those with real experince in processing those woods.

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Hi Nathan Slobodkin,

You obviously know a lot about trees and wood! Perhaps wood and trees behave and grow according to the condition in the area?

This photo is of a section of eucaliptus from Australia. You can see how different the heartwood is to the photo of the laburnam I posted earlier. There is a lot more volum loss from the heartwood.

The diameter of the trunk is about 2 meter.

post-5577-0-94696700-1356779131_thumb.jpg

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Thanks for your post, Nathan. I finally understand the difference between the sap and water flow in the tree. This makes a lot of sense. I remember reading somewhere that a maple tree should always be left on the ground for a few days after cutting. Whether this is always done or not I don't know, but the question is to what extent this would be useful if the tree is cut in winter since the leaves have already fallen. I suppose it is most useful when the tree is cut in summer.

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This photo is of a section of eucaliptus from Australia.

Great photo. Would you mind if I stole this photo to use whenever discussions about slab vs. quarter cut, and "strong winter grain lines" comes up? It's a great illustration of what wood actually does.

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Great photo. Would you mind if I stole this photo to use whenever discussions about slab vs. quarter cut, and "strong winter grain lines" comes up? It's a great illustration of what wood actually does.

Hi,

I took the photo in a sculpture park but forgot the name of the artist. Youcan use the the photo. Next time I go to the place I wiil note the name as he has left a permanent wooden fixture: 76 oak steps on a hillside, set in Welsh anthracite!

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Eucalyptus is unique - obviously there's not a lot in Scotland (!) but a local sawmill got a load from a tree surgeon in this sort of condition. Slightly smaller diameter of course ....

The opening up of the heart and the major radial cracks travelling outwards aren't just end checks as in a regular European hardwood - they travel all the way up the log. If you drop a tree from a timber grab it will open up like a Terry's chocolate orange.

For reasons of its unique structure, eucalyptus has to be quarter-sawn, and I seem to recall there are special mills in Australia that do this mechanically.

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I live in New England and spent my childhood hauling sap buckets. Anything that runs out of a tree late spring and throughout the summer is water, not sap in the same context as what produces syrup. The sap starts to form in the fall when the tree stops absorbing water (hence, no water flowing from the cut branch) Actually the highest sap content is late winter-early spring. Anything cut in the summer would be wetter but would not have sap in it, but anything cut during the winter will. I do have to add my personal opinion here, if there is "sap" in the wood how can it matter? if you take all of the sap from one billet and boil it down you may have enough to put a glob on the head of pin so I do not see how that much sugar could be a concern.

Hi,

A tree is a wonderful piece of natural engineering! The sap can flow in any direction; up, down, towards the centre.

I was warnishing a violin in 2008 in Agust. I heard a cracking noise, looked out of the window and sow a willow tree split into half,. there was no wind and no lightning, the tree came down because it took up too much water! After a dry period, there were two days of rain but the weather was warm and sunny when the tree split in half, one half broke and bent near the ground, the other half stayed upright for a few hours but broke about 15 feet from the ground. Here are two photos:

Anything cut in the summer would be wetter but would not have sap in it, but anything cut during the winter will. I do have to add my personal opinion here, if there is "sap" in the wood how can it matter?

The water or sap in the wood always contains some impurities; sugar, salt, acid, or mineral. When the wood dries these solidify and make the wood cut in summer heavier.

post-5577-0-57274900-1356974682_thumb.jpg

post-5577-0-95955900-1356974702_thumb.jpg

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Hi,

A tree is a wonderful piece of natural engineering! The sap can flow in any direction; up, down, towards the centre.

Sap can be a confusing term because it simply means fluid that flows through the vascular system of a plant. However it is not all the same.

The xylem transports water, minerals, and some dissolved carbohydrates from the roots up to the stems and leaves. Flow through the xylem is unidirectional.

The phloem transports nutrients (e.g. sucrose) to all parts of the plant that need nutrients, including the roots, in a bidirectional manner.

Cornell University has a very good description of sap flow with regard to making syrup (http://maple.dnr.cornell.edu/produc/sapflow.htm). A link at the bottom of the page will take you to the Cornell Sugar Maple Research & Extension Program if you're really interested in making syrup.

-Jim

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Cornell University has a very good description of sap flow with regard to making syrup (http://maple.dnr.cor...duc/sapflow.htm). A link at the bottom of the page will take you to the Cornell Sugar Maple Research & Extension Program if you're really interested in making syrup.

-Jim

Nice, little article. Thanks for the link, Jim.

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Sorry, I don't understand your comment.

Hi Jim,

Many of the assertions in the link are incorrect. Thermo-dynamics play a major part in plant life.The changing temperatures are like you squizing a spunge; the sap goes where the pressure is least.

Have a look atthe photos on post#46, it is the exposed root system af a small maple tree, this one.

post-5577-0-84105000-1357125200_thumb.jpg

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Wolfjk,

They, and I have addressed the effects of temperature on suction and pressure. Do you have a specific function that you are interested in that has not been addressed, or that you feel has been incorrectly addressed?

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Wolfjk, if you don't like information from Jim, or Nathan (who has done a lot maple cutting?), or the Cornell University Sugar Maple Research & Extension Program, or the University of Tennessee College of Agriculture and Natural Resources (a major hardwood producing state), what would you consider to be more reliable sources of information, and why?

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Hi,

There may be as much woody material under ground as above it.

Almost forgot this part. It's is easy to mis something if a bunch of questions/statements are crammed into a single paragraph, for me anyway. If you are interested I can post a formula where you can estimate the above and below ground mass of a tree when I return to the office next week.

-Jim

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The reason we always did winter cut wood is because it hangs on to the bark better....we were mostly cutting boule for cabinetwork. This plus the temperature does not promote fungal growth.

Joe

What's the benefit of the bark for your work?

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Wolfjk,

They, and I have addressed the effects of temperature on suction and pressure. Do you have a specific function that you are interested in that has not been addressed, or that you feel has been incorrectly addressed?

Hi Jim,

Thanks for your posts.

Thus, pressure and suction are essential to sap flow. But how do the pressure and suction develop?

The life of trees and every living thing in the universe is a mystery! However we can be certain that the maple tree was not created to yield maple syrup! The primary function of all living things is survival and reproduction. So we can be reasonably certain that sap in the maple tree is to make the woody material but more importantly to produce the seeds.

At night or during other times when temperatures go below freezing, the carbon dioxide cools and therefore contracts. Some of the carbon dioxide also becomes dissolved in the cooled sap. Finally, some of the sap freezes. All three of these factors create suction in the tree. This causes water from the soil to be drawn up into the roots and travel up through the sapwood. When temperatures rise above freezing the next day, sap flow begins again

Don’t you think logic would dictate that the outside of the twigs contract first and push the sap down? Isn’t carbon dioxide a by-product of photosynthesis and escape through the leafs? If sap freezes would not the tree explode?

Pressure inside the tree is created by heat and light. It is simply governed by the laws of thermo dynamics. When the temperature rises material expands, living or dead when it falls everything contracts. You mentioned in your post estimating the amount of roots under ground. Consider the area of the branches of the tree. It is a very big are. The smallest of temperature changes affect the small branches first and that is where the difference in pressure starts. In spring when temperature rises, the twigs pick it up first and their expansion creates the pressure difference that causes sap flow. However there are things happening underground as well. The frosty ground thaws from underneath and re activates the root fibres.

In autumn time the process is reversed. The twigs contract first and create downward pressure. The sap goes towards the roots and causes the white root fibres to shoot outwards. You can see it if you look under the roots in November? December.

I’m sure you’re familiar with the structure of the individual wood cells. I f you disregard the cells in the process of forming, the mature cells allow the sap to flow up, down and towards the centre. I’m sure tapping the trees don’t cause any major problems. Pine trees are tapped for resin, gum trees are tapped for gumshoes. However tapping reduces the internal pressure and has similar effect as shedding a branch or other injuries to the tree. It causes slower growth.

Finally the root cells are quite different from the cells in the trunk. They do different tasks.

In human and animal life there is one other very important factor; the quantum nature of life! We have a soul! Apart from the physical energy we get from burning food, we need quantum energy from, light heat, ideas, emotions and art, including music. Perhaps trees have a soul as well?

Here is a photo of of an old oak from the Robin Hood era: :)

I forgot to mention that the photo illustrates the difference between the structure of the trunk and the root

post-5577-0-72942800-1357162093_thumb.jpg

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Wolfjk, if you don't like information from Jim, or Nathan (who has done a lot maple cutting?), or the Cornell University Sugar Maple Research & Extension Program, or the University of Tennessee College of Agriculture and Natural Resources (a major hardwood producing state), what would you consider to be more reliable sources of information, and why?

Dear David Burgess,

If I did not like information from people I would not respond to their post. I regard every post as good information in some way or other.

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Dear David Burgess,

If I did not like information from people I would not respond to their post. I regard every post as good information in some way or other.

Then why responses like,

"Hi Jim,

Thanks for the links. It is a nice little fairytale! :) The actuality is quite different!"

And

"I feel sorry for their (University of Tennessee) graduates!"

Don’t you think logic would dictate that the outside of the twigs contract first and push the sap down?

No, I think logic would dictate that a gas like carbon dioxide has greater thermal expansion than wood, along the lines of Jim's explanation.

I

In human and animal life there is one other very important factor; the quantum nature of life! We have a soul! Apart from the physical energy we get from burning food, we need quantum energy from, light heat, ideas, emotions and art, including music. Perhaps trees have a soul as well?

Perhaps we would be getting better tonewood if we all spent more time hugging trees?

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