old dead wood from a tree stronger than any other wood from that tree?

This is a question following from several observations of a elm tree. There was an elm tree that was wind damaged and the limbs finally came
down after several years hanging in the tree. It was old and dry but very strong and much harder to break than a green limb.
So I am wondering what is the preparation for the strongest wood from a given tree. Whether the weakest wood is the green alive wood. Whether cut wood that is dried in a dryer is stronger than green wood. And finally whether the strongest wood of all is to kill the entire tree and let it dry for several years and then harvest the wood.
If true, what is the explanation?
Archimedes Plutonium www.iw.net/~a_plutonium whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies
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Explanations I don't have, but it's well known that locust wood (commonly known as "ironwood") can be fairly easily cut when green, but is some of the toughest wood in the world after curing. If you have a locust tree come down in your yard, you'd be wise to cut it up immediately. After as little as a few weeks it may be hard enough to wear out a chain saw. You can hurt yourself, even break a bone, trying to cut cured locust limbs with a sharp axe (just bounces off). Locust fence posts commonly last MUCH longer in the ground than will pressure treated pine or fir. Greatly preferred by farmers, but they ALWAYS cut the wood while it's green. Otherwise, it's for the landfill.
Mark 'Sporky' Stapleton Watermark Design, LLC www.h2omarkdesign.com
Archimedes Plutonium wrote:

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Dry wood is stronger than green wood. Go look it up in the authoritative Wood Handbook, which you can find online chapter by chapter as free downloadable .pdf files. See chapter 4 on mechanical properties. http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch04.pdf See Table 4-11a on page 4-28 showing the difference between green wood and dry (~12% moisture) wood. Read the rest of the book for explanations.
Pittsburgh Pete
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The strongest tissue is always the sclerenchyma, those cells of the tree whose purpose is to strengthen and stabilize. Technically, sclerenchyma cells are 'dead', in that moisture has migrated from the cell leaving only the lignan (hence, 'lignification') behind.
Dave

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Thu, 30 Dec 2004 17:12:51 GMT David J Bockman wrote:

Thanks for the information. I will keep it in my notes file, who knows it may come useful in future.
Say, you would not know whether animal bodies have a cell which produces the strongest and stabilizing form that is the analogy to sclerenchyma???
Archimedes Plutonium www.iw.net/~a_plutonium whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies
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