How to age a living tree

[overgrownbramble]

May see like a silly question, but how do you roughly age a living tree?

Specifically, I've got thre silver birches in my garden which look on their last legs. Many branches drop off daily, there'a always a pile of dropped branches on the ground under them, one has even lost one of the two main shoots from the trunk and the remaining part is rotting. All the bark is loose, birds dig away at the trunks liek it's paper, and it's full of woodlice etc. Also none of them has the typical shape birches are supposed to have, they're tall with a round lollipop shape.

And yet, they are still alive with insects and birds, produce copious seeds and catkins, so they must be in great health?

[nightshade]

Supposedly Birch is not a long lived tree,my weeping birch
has been around for 32 years some Paper birch have been
around for 132 years!My tree is about 18 inches in circum
ference

[henrya]

Originally Posted by overgrownbramble

And yet, they are still alive with insects and birds, produce copious seeds and catkins, so they must be in great health?

Copious seed production is not necessarily a sign of good health in plants. Some plants respond to stress by producing seeds - if the plant is going to die soon it's a good idea for it to reproduce.

As far as I know, there is no easy way to age most plants - tree growth in particular depends on a variety of factors - soil type, amount of water, amount of wind exposure, amount of light etc etc. Think of bonsai trees!

henrya

[svenrufus]

Rule of thumb I was given a while back is that you take a measurement of the girth at about waist height, in centimetres, and divide it by 2.5. The resultig number is the age. This is a rough estimate only. As has been mentioned by someone else, trees grow at different rates according to conditions, and also according to species.

Birch have a short lifespan, so if they have already reached a good size, they may well be on he way out already. I heard somewhere, that the whole lifecycle of seedling to rotted away, can be over and done with in less than 100 years!

If you can leave them in place, ie if there is no risk - or a risk you feel comfortable with - of being hit by falling bits, they are valuable habitat as standing dead wood. When you feel they need to be felled, leave them on site to carry on rotting on site.

[Brachystegia]

Whilst it doesn't include birch, the Forestry Commission has a very interesting publication explaining how to non-destructively estimate the age of trees, assuming you don't want to take a core sample and count the rings.

find it at: http://www.forestry.gov.uk/website/P...ILE/fcin12.pdf

[Susie]

For ancient trees you can use arm spans - someone told me that for every person's arm span it is approximately 100 years.

It may not be accurate but it is good for a giggle when there is a group of you holding hands as you hug a tree trying to guestimate it's age.

It is a great way of breaking the ice when you are with a group of strangers on a nature ramble.

[overgrownbramble]

Thanks all, my best guess is max 50 years old as that's roughly when the houses were built... either way, if they die off completely I will leave them alone to complete the natural cycle - there's no worry about safety as so many branches fall off I think there'll be just the main ones left by then! Also the birds all use them as lookout/eating posts and so on, so even if they're bare in summer I'm sure they'll still be loved by the locals birds.

The odd thing is that I've never seen a seedling despite all the seeds and catkins indoors and out!