Hambone said:
It's alway's been my understanding that "old growth wood" DID NOT have ample nutrients, water, and sunlight. This was caused by the forrest's in the past being more dense than what we have today. Young trees had to fight for nutrients and sunlight because the older trees had never been logged. This caused the trees to grow at a much slower rate.
You could possibly find some examples of tight grained wood at higher altitudes nowadays because of the low oxygen content but I'm not sure it would be anything useful for shaftwood.
This is not completely accurate. You mention some things of value, but they need to be clarified.
The key word in "old growth wood" is old. It does not necessarily mean it grew on a site that was limited in any of the 3 requirements you listed. It could have been nearly an open grown tree. It would have fast growth up to a certain point, then the growth characteristics of the tree would change. After many many years, a tree will simply stop growing as much, and the grain lines will become tighter. If the site is a good site, the wood will be good, just not all of it will have the "old growth" characteristics. If the tree is old enough though, portions of it would be great candidates for good shaft wood.
It is true a site can only sustain so much volume because of limits of nutrients, water, and sunlight. But low nutrients, light, and water do not make old growth wood. The result is poor wood. The grain lines may be close, but the wood will be of poor quality, and some trees will be supressed and die. Natural mortality will take over if there is a limit of of nutrients and water, the trees will not hang on long enough to achieve any idea of old growth. This is a fact in silviculture that cannot be denied. With some of the trees now dead, the resulting ones will either put on more diameter growth, or more height growth, depending on their pecking order in the stand.
If you have older trees that have not been cut, and you have thriving trees in the understory that are healthy because there is sufficient nutrients and water, they will have slow diameter growth, but it will be healthy wood. The tree will be putting on more height growth in order to reach more sunlight. It will eventually become a co-dominant or dominant tree, but by then it will be very mature. Once it reaches that point, he will be an established tree in the stand, mature, and its natural growth rate will be very slow due to its age. It will make for great shaft wood material. Another side affect is because it was an intermediate always fighting for height growth, there will be a smaller crown ratio. There will be less branching towards the bottom of the tree, making cleaner boards with less knots to kill the wood for shaft purposes. These trees are golden for shaft purposes, but not because of limits to nutrients or water. Rather, because of its natural growth dependencies, crown class (its relationship to other trees in the stand), stand changes over time, and maturity.
The trees that are already dominants in the stand as the stand is growing will be putting on more diameter growth due to more sunlight. They will grow taller, but most of the growth will be in diameter. That would make slightly larger gaps between the growth rings, again, until it grows very old and its growth in girth becomes very small naturally.
You can cut any tree down that is lived to be a very old age and track stand changes (and weather to a degree) and its affect on the tree by a growth ring analysis.
Kelly