The truth about finding a sugar maple age.

1. That age equation below will not work for two major reasons. 1. It
assumes that the trunk of a tree is perfectly cylindrical. Of course, no
tree trunk that I have ever seen is a perfect circle, although some species
on some
sites come close. Sugar maple very seldomly comes close. 2. The growth
rate is not correct. Sugar maples grow differently throughout their range.
Sugar maples grow anywhere from Canada (Northern Ontario) to Georgia in some
of the better sites of the blue ridge mtns. They can possess increments of
anywhere from 1/16" (1/8" growth in diameter per year) to 1/4" (1/2"
diameter growth per year) increments, depending on their location.

2. Some advice below this post has suggested that diffuse porous (wood
without vessels) wood is not easily aged by taking a increment sample with a
increment borer. This has some validity to it. It's sometimes tough.
Personally, I have tried to get the age of sugar maples, and it is my
opinion that it makes a significant difference what area you are in and what
season it is (because sugar maples produce lots of sap in spring-early
summer). Using an increment borer, I would suggest that it would be best in
fall to make the core and get some increment bore dye from forestry
suppliers (I'd suggest Ben Meadows, but they don't sell it anymore)
www.forestry-suppliers.com, and dye the increment with the chemical. This
chemical will dye certain parts of the wood (the lignin) a particular color
while it does not stick to the other parts of the wood, therefore making
summer wood (the large part of the ring) contrast with the winter wood (the
smaller part of the ring) so that the rings can easily be seen.

3. Boring an increment will very likely not do damage to the tree as long
as you keep your increment borer clean (e.g. treat it with a bleach solution
to kill any pathenogens) prior to boring the hole. If you are really
concerned about it, paint a little of this same bleach solution along where
the cambium meets the wood. Of course the only area where fungi can attack
a tree is the growing section of the tree (the cambium), the interior wood
is dead. There are other "stains" and such that may discolor or decay the
wood, but in general, as long as there is enough structural integrity in the
dead wood to support the tree and the living tissue is healthy, the tree
will continue to grow (although more slowly at this size).

4. What I would suggest is taking a small increment of maybe 4" or so,
measure it with a tape measure, count the rings in that 4" to develop an
average rings per inch ratio and multiply that number times the diameter.
Use a diameter tape or the average of three ways around the trunk using a
diameter caliper to get the diameter figure. Using this "sampling"
approach, you will have a very close estimate of how old your tree is.

5. Last considerations: Trees grow quicker in open environments early on
than they do as they get older. This must be taken into consideration to
get a closer estimate of the age. Up here in Mid-Michigan, the average
diameter growth for sugar maple is probably less than 1/8" per year (takes 8
years to put on 1 inch of diameter growth - but this is in a forested
environment). Also, it takes 8 years for the smallest seedling (cotyledon
just coming out of seed) to reach 54" height on an average site in the
Northeast.

Hope this helps you.

Good luck,
Geoff Kegerreis

To learn more about forests and forestry, browse timberline forestry
consulting at
www.timberlineforestry.com



kate wrote:

The tree is 60 inches in diameter at the 5 foot level, and is in a
residential front yard in Nashville TN. There was a Silver Maple that
shaded it somewhat, but that went down a few years ago in a tornado. By
the chart used from
http://www.learner.org/jnorth/tm/leaf/HowOld.html

I figure if it was in a forest it would be 95 years old. How would I
figure age in a non forest area?

Kate

PS - Thanks for the great book recommendations - I'm about half way
through Forest Primeval and I'm seeing the woods I frequent in a totally
new light! (And I love my Textbook of Dendrology!)