Estimating Tree Age when looking for older sites

[gitterdug]

One of the things I love to do, is hunt older sites, mainly in the country. Here in Texas around my particular area (DFW), we don't go past about 1850's. In the country, driving around, I am always on the lookout for old homesites. I watch along creeks for rocks, vegetation, remnants of log cabins, etc., but from a distance, the biggest thing I see most of the time, are the out of place trees, built into a row, or a square, or by nature of their species, out of place.

Have you ever wondered about how to determine the age of a tree in the field? We can guestimate.....oh, a big ol' oak tree is 150 years, or a thick mesquite tree is 75 years, etc.

I stumbled across the following information and thought it might be of some value to someone on here, if for nothing else, than to help narrow down a site's age.....circa 1930 vs circa 1850. So, I hope this helps someone. I have this on my iphone and use it sometimes.

Finally, how do you folks determine ages of vegetation?



The Tree Aging Formula

Begin by determining the tree species and taking a diameter measurement (or circumference measurement) using a tape measure at Diameter Breast Height or 4.5 feet above stump level. If you are using circumference, you will need to make this calculation to determine the tree diameter: Diameter = Circumference divided by 3.14 (pi) I use the Audubon Field Guides app for my iphone to determine species if I am not sure, and there are a lot of apps out there.

Then calculate the age of the tree by multiplying the tree's diameter by its growth factor (see below): Diameter X Growth Factor = Approximate Tree Age. Let's use the hickory above to calculate age. A shagbark hickory's growth factor has been determined to be 7.5 and its diameter is 10 inches: 10 inch diameter X 7.5 growth factor = 75 years. Remember that the growth factors I provide are more accurate when taken for forest grown trees.

Growth Factors by Tree Species

Red Maple Species - 4.5 Growth Factor X diameter
Silver Maple Species - 3.0 Growth Factor X diameter
Sugar Maple Species - 5.0 Growth Factor X diameter
River Birch Species - 3.5 Growth Factor X diameter
White Birch Species - 5.0 Growth Factor X diameter
Shagbark Hickory Species - 7.5 Growth Factor X diameter
Green Ash Species - 4.0 Growth Factor X diameter
Black Walnut Species - 4.5 Growth Factor X diameter
Black Cherry Species - 5.0 Growth Factor X diameter
Red Oak Species - 4.0 Growth Factor X diameter
White Oak Species - 5.0 Growth Factor X diameter
Pin Oak Species - 3.0 Growth Factor X diameter
Basswood Species - 3.0 Growth Factor X diameter
American Elm Species - 4.0 Growth Factor X diameter
Ironwood Species - 7.0 Growth Factor X diameter
Cottonwood Species - 2.0 Growth Factor X diameter
Redbud Species - 7.0 Growth Factor
Dogwood Species - 7.0 Growth Factor X diameter
Aspen Species - 2.0 Growth Factor X diameter

Perhaps this is overkill for some folks, but when I am looking for that one special site to hunt, I want to know the site's age going in. At 60, in my overall physical health, I ain't diggin 9000 holes needlessly. I like the oldest sites I can get to, and though I don't always use this information, I do use it. LOL Chew the Cambium, spit the bark.

 

[Buried Crap NJ]

I like your thinking. I often look at area's undeveloped within parts of towns. I can't for the life of me figure out why the trees are bigger than what they should be?
BCNJ

 

[AngelicStorm]

Thanks for this information. I'm sure it will be helpful to not only me, but to many other people (those who actually take notes of it lol). I have quiet a few sites that have really big trees that just from looking at them I would guess to be 100+ years old with some 200+ years old. I might be able to come up with the approximate age of some of these trees now. Thanks.

 

[GKMan]

good info. I would recommend picking up Reading the forested landscape or Forest Forensics by Tom Wessel when I am out in the woods I try to use his advice to read what happened in the past in the area that I am detecting.

 

["Dr.Tones"]

Great info! Thanks!

 

[AngelicStorm]

It's ironic you posted this just in time for me to see the largest registered tree in my county in the Live Oak Family. I saw this Oak Tree for the first time today and using this formula I came up with that it is anywhere from 259 years old to 324 years old. To bad I didn't detect around it. It looks promising.

 

[E-Trac-Ohio]

Good post - I never thought of putting this info. in the forum !

I cut timber for a living so I always look at how old the trees are when I hunt a site, without even thinking about it.
It's also a good idea to look at where the root flare meets the ground - this will tell you if there's been any changes made to grade / dirt level.
Around big tree is always a good place to hunt - a lot of people sit under them to get out of the sun or other bad weather or just use them as a back rest.
I've made some pretty nice finds under real big old trees over the last few years.

Thanks again for the post !

 

[gitterdug]

n/t

 

[GKMan]

Gitter , I don't think our forefathers were watering and fertilizing the trees in their field

 

[gitterdug]

n/t