Tree rings

Asked January 7, 2019, 9:09 AM EST

The pictures are of a pignut hickory cross section. I’m counting 23 rings between 2” and 3” on the ruler. Is that close to the right number? (Tree rings always looked obvious to me.) If it is, the tree, with almost 11”from center to bark, is close to 250 years old. I used a belt sander to get a better surface, but it didn’t remove much wood. The wood is very hard.

Lorain County Ohio

6 Responses


It sure looks to me like you are seeing the rings correctly. When I zoom in to the image on my computer it gets a bit fuzzy, but it looks to me that there are 22 or 23 rings in that inch. The 23rd ring appears to begin at the 3rd inch. So if I had to make a call I'd go with 22 in that inch.

It gets pretty tedious, but I recommend using some magnification and marking every 10th ring with a pencil from the center (pith) to the outer edge under the bark (cambium). This makes it much easier to keep track of the rings.

Hope this helps... Feel free to contact me by email or phone if you need more information.

Thank you for your answer. I don’t need an exact age. The tree identification puzzle has been fun for me. I help a farmer cut downed trees. I just never saw tree rings this close together and so indistinct. The light colored “dotted” portion is interestingly thin and intermittent in places. The reddish heartwood ending abruptly at the yellowish sapwood is striking. I’ve learned a lot figuring this tree out.

I am am using a magnifying glass, flashlight, and compass point. Still,in places I use my average count as a best estimate.

You are quite welcome. Trees are fascinating and nothing more so than exploring the phenomenon of annual growth rings. I'm guessing that this tree grew under fairly shaded conditions and on a fairly dry site for most of its existence.

You’re correct! It’s about 120’ down the east steep slope of Chance Creek, a tributary of the Vermilion River in Lorain County’s lake plain. The creek made valley is cool enough further down that there are nice groupings of hemlock trees - stranded here since the ice age. There are nice oaks and beech on the slope also. So therewas shade from the trees and the slope as the tree grew.

I substitute teach in Lorain city schools, and I’m using ring sections of the pignut hickory and an ash to show students. They don’t know about tree rings. I’d like to confirm A. & C. I would appreciate it if you have an explanation for B. Thanks.

A. #1 the light brown in the first picture is inner bark - larvae were eating and left cavities. I scraped powder out of one cavity. Most of the bottom six feet of trunk was rotted. I assume inner bark containing carbohydrates from the leaves was the target I flipped a 6’ bark section off the bottom and hundreds of 3/4” insects ran for cover. My pictures come from 10 feet or so up

B. #2 & #3 The “stain” and black lines travel through the section. I don’t know what they are.

C. I assume #4 is a dead branch that was over grown by the tree.

This is an excellent resource that could help to explain some of what you are seeing:

A. EAB feeds in an area just under the bark (phloem, cambium and outer surface of xylem). The powder in the cavity is likely frass from their feeding. I'm guessing the insects that scattered are secondary and not EAB. Can you describe the insects that ran for cover? When did this happen?

B. Black lines are likely the edge of decay. See publication above and description of how damage is isolated (compartmentalized) in trees.

C. It looks like there was some like there was some wounding that occurred just above or below this point. It could have been a damaged branch from pruning or just some wounding to the cambium area. Difficult to know. It looks a lot like what we see from fire damage (fire scar) , but this is not likely to be seen this high in the tree. There are two similar wounds to the left.

Hope this helps...Feel free to contact me directly if you need more clarification.