Working out the age of trees

[Woocash]

Hi all. I’ve seen quite a few bonsai, or rather Yamadori that someone has claimed is this age or that age and I was wondering how on earth can someone even hazard a guess as to the age of a stunted dishevelled old tree with a trunk diameter of say, a twenty year old “healthy” tree? I’ve seen at least a handful of 500 year old claims, but how can that even be possible? I mean, who’s to say what the difference of 300 or 400 years could be without cutting through it? I’m sure there are plausible reasons for the guesses but are there any good reasons as to why?

While I’m at it, how long is a piece of string?

 

[just.wing.it]

I think the more important question is this:
How old can you make your tree look?

Sure starting out with old material is nice and helps the illusion of ancient age in bonsai terms....but this art is a visual art form, and its all about the illusion.

Edit....and your question remains....and its a good one.

 

[Woocash]

I think the more important question is this:
How old can you make your tree look?

Sure starting out with old material is nice and helps the illusion of ancient age in bonsai terms....but this art is a visual art form, and its all about the illusion.

Edit....and your question remains....and its a good one.

Exactly, so why even make a claim other than to give unnecessary emphasis to a find you’re particularly pleased with?

 

[just.wing.it]

Exactly, so why even make a claim other than to give unnecessary emphasis to a find you’re particularly pleased with?

Id like to hear from @Walter Pall on this one, if you'd be so kind, sir.

 

[MrWunderful]

Small core sample?

 

[just.wing.it]

Small core sample?

Only to find a hollow center!!! Damnit!

 

[Dav4]

Hi all. I’ve seen quite a few bonsai, or rather Yamadori that someone has claimed is this age or that age and I was wondering how on earth can someone even hazard a guess as to the age of a stunted dishevelled old tree with a trunk diameter of say, a twenty year old “healthy” tree? I’ve seen at least a handful of 500 year old claims, but how can that even be possible? I mean, who’s to say what the difference of 300 or 400 years could be without cutting through it? I’m sure there are plausible reasons for the guesses but are there any good reasons as to why?

While I’m at it, how long is a piece of string?

Trees of a particular specie will grow and gain trunk girth at a predictable rate in a given micro-climate, based on core sampling and other accepted means of evaluating age. Apply the expected growth rate of a given species of tree in a given location to the trunk girth of your specimen and you can arrive at a close approximation of age... but the only way to accurately know is to cut and count rings or core sample.

 

[VAFisher]

Trees of a particular specie will grow and gain trunk girth at a predictable rate in a given micro-climate, based on core sampling and other accepted means of evaluating age. Apply the expected growth rate of a given species of tree in a given location to the trunk girth of your specimen and you can arrive at a close approximation of age... but the only way to accurately know is to cut and count rings or core sample.

I think that's how Andy Smith arrives at his estimates. He's core sampled a shit load of trees in his work and can make a pretty educated guess about collected trees. Not that it really matters anyway, but I tend to trust his numbers.

An interesting thing happened to me this weekend at my club show where I was showing my water oak. The club wanted the age of the tree to list on the display card. Having no idea, I took a guess of 20 years. One of the members argued that it was much older than 20 and might be 60 or 70. I doubt that since it's not even fully barked up, but took it as a compliment anyway. In the end, it doesn't matter.

 

[leatherback]

You take a piece of deadwood wher eyou can count the ring, and extrapolate.
You take a dead tree in the same location, cut it and count

 

[Forsoothe!]

You might be able to extrapolate a range from a low stub. If you can count the rings of the stub and measure the diameter, and calculate the thickness each ring spans, that will give the growth rate per year. It should be representative of growth at that site for that species.

 

[Walter Pall]

Id like to hear from @Walter Pall on this one, if you'd be so kind, sir.

The exact age of a bonsai is not really important. But people want to get a number. The truth is that we try to make it look older than it really is. The other truth is that in case of doubt I would prefer the YOUNGER tree because it is more vigorous and has longer life expectancy.

With a lot of experience we can do a good educated guess for most trees. You must have a few trees with verified age. This one can get by cutting the trunk and counting the rings - often with a microscope. Or there is the scientific carbon method. Anyway, if you know for certain the age of several trees which were fond in comparable situations you can do an educated guess for a tree form similar conditions.

I had a Rocky Mountain Juniper which had 1,800 or so rings. Another one had almost 1,000. I know it's hard to believe, but this is pretty normal. We have cuttings from ponderosas and Rocky Mountain Junipers that show 100 rings per inch or more. this means that a tree which has a trunk diameter of two inches and comes from similar - very bad - conditions in a similar area would be about 100 years old. A tree with diameter of 8 inches would be 400 years old. This sounds exaggerated, but it normal for insiders.

With very old trees I tend to give a LOWER age than I really think to avoid discussions like this one.

 

[Woocash]

Fair enough all, thank you for your answers. I can well believe that lots of trees are in-fact at the age they are stated to be, by the way, I just wondered how it could be estimated when they are often so restricted in growth. I assumed the estimate would mostly be of the main trunk, whereas the roots are where the true age lies and it’s far harder to guess as the trunk could be the second or third one etc in it’s lifetime (hence the low estimations from Walter Pall I suppose).

Counting the rings of branches and collecting core samples I can understand, but isn’t cutting down a 500 year old tree to tell the age of its neighbour a little unethical? Or does a branch get cut and then we extrapolate from there?

 

[Walter Pall]

Trees often die after collection. Then they can be cut through the trunk and we know tha age.

 

[Woocash]

Ah yes I suppose thats true. Thank you, I’m just trying to get a better understanding of the subject, not to insult people’s years of experience.

I have a hedgerow near me which is clearly very old with huge girthed, but extremely gnarled Hawthorns, Crab Apples, Elms, Maples and Hazels. I would love to know their age as they are clearly older than any other similar trees in the area. I just speculated that maybe some people would speculate on its age rather than have any basis of fact. Core samples seem like a possibility.

 

[Forsoothe!]

The word you are looking for is prevaricate. When describing the lifespan of a tree we need to use the word "guess" liberally, unless it's dead and we preformed an autopsy. Living things get to keep some secrets.

 

[peterbone]

Ah yes I suppose thats true. Thank you, I’m just trying to get a better understanding of the subject, not to insult people’s years of experience.

I have a hedgerow near me which is clearly very old with huge girthed, but extremely gnarled Hawthorns, Crab Apples, Elms, Maples and Hazels. I would love to know their age as they are clearly older than any other similar trees in the area. I just speculated that maybe some people would speculate on its age rather than have any basis of fact. Core samples seem like a possibility.

Almost always when you collect a tree in the UK you will be chopping down from a larger tree and regrowing an apex. By counting the rings at the chop point you can get an accurate estimation of age. You can also count the rings of the tap root removed, since that starts growing right at the beginning of the tree's life. I often keep a disk of wood taken from these chops as reference.

 

[Tieball]

You might be able to extrapolate a range from a low stub. If you can count the rings of the stub and measure the diameter, and calculate the thickness each ring spans, that will give the growth rate per year. It should be representative of growth at that site for that species.

Cool.....sounds like the start of a story problem from a math class.

 

[penumbra]

The word you are looking for is prevaricate. When describing the lifespan of a tree we need to use the word "guess" liberally, unless it's dead and we preformed an autopsy. Living things get to keep some secrets.

Forsoothe, I haven't heard that word in 40 years. The problem with prevaricate is that one has to be careful of the context in which it is used. It can mean anything from equivocate to lie. It is a great word seldom used with the literal definition meaning to deviate from the truth.
Yours is an excellent post in an excellent thread.

 

[rockm]

Trees of a particular specie will grow and gain trunk girth at a predictable rate in a given micro-climate, based on core sampling and other accepted means of evaluating age. Apply the expected growth rate of a given species of tree in a given location to the trunk girth of your specimen and you can arrive at a close approximation of age... but the only way to accurately know is to cut and count rings or core sample.

The formulaic approach can give an idea, but in practice it depends wildly. For instance, the live oak below has a trunk diameter of 6 inches or so. It is almost 250 years old--I was lucky because the oldest part of the tree was cut back at collection. I counted the rings (the only real way to tell exact age of a tree). 250 year old live oaks generally are over 50 feet tall and have trunks that are several feet in diameter.

I've also dug old looking trees in the woods to find they are mostly under 50 years old, while the younger-looking, small tree next to if of the same species is five times as old...

Anyway, the actual age is really not all that important (unless the tree is obviously ancient--and that can be self-evident), it has to LOOK old.

 

[penumbra]

Actual age is perhaps important, and if not it is certainly interesting, but I am more inclined to wonder how long a tree has been in training.