Help with this oak

[Phorester]

Age of trees with diameters larger than an increment borer's length can be extrapolated as BEENTHERE says.  I bore as far as I can, measure the core length to an exact  inch (for instance if it's 6.5 inches long, I drop back to the 6" spot).  Then count all the rings in that length of core, divide by the number of inches to get an average number of years per inch, then multiply that by inches of radius. I might hedge that number based on where the tree is growing, etc. Works pretty well.  I estimated the age of 2 yard trees in different yards by this method.  One was 135, the other 180. Both homeowners said that's when the houses were built. Since it would have been logical that trees were planted in a yard when the house was new, I figured it was pretty close to the trees' actual ages.

I also have a chart at my office that estimates tree age by species, based on the diameter.  Don't know how in the world  these were determined.  I've checked it with actual tree cores and it sure is close.

As far as ages and sizes, I've seen a 30" diameter Norway maple yard tree that was 60 years old. It died from verticillium wilt and was cut down, so I could count the growth rings on the stump. I've counted rings on stumps of street trees in our town that were cut down.  One had a 16" stump and was 24 years old. The flip side -  Bored a 12" diameter chestnut oak on top of a steep, dry, south facing ridge that was 160 years old. I have a 4" diameter white oak beaver biscuit at my office that has 75 rings in the radius.

[locustoak]

Hm...what happened to flip?   I would love to see more pictures of this ancient tree, and possibly get my hands on a slab of the butt.

[clww]

That sounds bigger than the oak I'm currently working on. I'd like to see pics, too.