I have been told that for certain species of spruce trees you need to dug up the root system to correctly estimate the age of the tree. Rather than just taking a core sample would this be correct?
Some species of spruce grow very slowly. The height of the tree during it first twenty or thirty years is probably measured in inches. If you take a core at five feet, you are going to miss the actual start of the tree’s life. Taking a core at the top of the root ball gives you a better chance of actually hitting the greatest number of growth rings.
However, any tree can have heart rot, and that will be more likely to have taken out the lower portion of the growth pattern. After a while, you have to decide how many cores you want to take, considering the health of the tree. Two is all I could recommend. Digging up the tree pretty much guarantees killing it.
Tris
Killing the tree isn’t the issue getting the correct date is.
Microscopic dendrochronology can handle very slow-growing trees, but that’s generally done by the pros.
I’m not sure how they are dated, but we have a large number of these where I live, so this thread perked my ear.
http://www.sonic.net/bristlecone/intro.html
4,767 years old.
We have a bunch of them on Mt. Brose (Colorado) a 10 mile jeep trip away from my home.
This doesn’t answer my question?
Is this correct?
I am specifically interested in White and Black Spruce.
Sorry to ask but do you have a cite for this?
So… you need to be above the root ball. The roots can’t determine age?
There aren’t growth rings in the root because it does not experience the seasonal growth like the trunk and limbs above ground?
woops… drowing here. Way over my head.
Very interesting tho.
The Heisenberg uncertainty principle at it most terminal
Not that I can link to, or give you isbn numbers for.
I can explain if you want. The wood created each year never actually moves. If a tree reaches one foot height at one year, the first “ring” of growth never moves above that. The following year, the trunk grows upward another foot, and all the wood above one foot has one ring, and below that, two. The next year you have a foot with one year’s growth, one with two, and one with three. Same story for as long as that trunk continues to grow.
So, to get the most accurate possible count of the entire age of the tree, you have to be sure to take your core at the point where the tree was growing in its first year of growth. That would be the point just above the core of the root system, or the root ball. Problem is, many factors can alter the lower most parts of a tree, including insect boring, heart rot, etc. Also, the main trunk can have its terminal bud damaged, or cut off, and subsequent main trunk growth can proceed from a different portion of the tree, in some cases from the root ball, in some case from a branch.
How far off is your estimate going to be if you core a black spruce three feet from the ground? A couple of years, probably not more than four or five. Cutting down the tree will give you access to all the possible multiple centers, and any rot patterns can be evaluated. How accurate do you need to be?
Tris
It seems I may have mispoken. Black Spruce grows even more slowly than I remembered. An inch or so in a year, as a seedling. So, you are probalby not going to be able to recover that first year ring by any means, if the tree is more than a decade or so old.
Tris
Found it thanks,
From the Canadian Journal of Forest Research. Volume 27, Number 8, August 1997, Is ring count at ground level a good estimation of black spruce age? by A. DesRochers and R. Gagnon.