Ash with bark wound

[jacquemontii]

Hi all,

 

Please see attached photos of an ash (stem diameter 60cm, height 12m).

 

This tree has a large wound exposing the non durable heartwood, which could decay rapidly and cause collapse. I understand that Fraxinus is a poor compartmentaliser of decay.

 

Given the tree is in a residential setting, my feeling is this tree cannot be safely retained for more than 10 years.

 

I am aware that ash can survive a mechanical failure and collapse, by retaining a viable wall of sapwood and producing adventitious shoots, to produce new stems and branches.

 

However, in this situation (residential targets) would anyone recommend any course of action other than fell?

[Mountain man]

Doesn't look very loved does it? Assuming no one gives a monkey's fell it.

If it's someone's pride and joy (unlikely by the look of it) you could hat rack it and start a pollard cycle.

[Adam M]

Looks like its had a hard life. Perhaps historic fire damage to the lower stem? Doesn't look too shabby up top though (although can't make out from the photo whether the union is compromised). Have you given the exposed wood a smack with a hammer? Jabbed anything in it yet? Retain as it is. Any reduction will surely limit its ability to deal with that damage and hurry it into its grave. Who's the customer? Enhanced level of re-inspection maybe on an annual, or annual and a half basis?

[Paul Melarange]

I agree with Adam. The wound warrants further inspection, a bit of a tap and a prod (particularly at the base of the wound). If its not hollow, it should be ok for a good few years yet.

[armybloke]

Showing good vitality - occlusions are sound and look good. Vascular 'piping' has found its way around the wound and looking at the crown shape and extension growth is doing well. A light prune to tighten the crown and 'offer' stability may be otherwise why the need to do anything? TR ratio of 1/3 will keep it upright. Move the detritus around the base of the stem would probably help it long-term. Look at the bifurcated stem and determine if there is any included bark in the union - that may present another issue? Difficult to judge from a pic and what's around the other side? Nice tree.

[Roger the shrubber]

Hard to tell from pictures but in my opinion looks like wound is occluding ok, see the reaction wood forming up either side of wound in first pic, i would reinspect when in full leaf. As others said check it with a probe and sounding hammer though., I wouldnt fell at this stage.

[jacquemontii]

Thanks to all for taking the time to comment on this.

 

I agree the tree looks good in terms of its current vitality, and I have noted the wound wood. I don’t think the tree is an imminent risk, however I’m trying to determine if the tree is viable for more than 10 years, as per the BS5837.

I would like to hear people’s experience of ash as a species. Is a wound of this size likely to occlude and isn’t decay now inevitable given that ash is known to have a non durable heartwood? Does anyone have any experience of the likely rates of decay for an ash of this size (60cm diam)?

[Paul Melarange]

It interesting that you have applied the tree quality assessment from BS 5837:2012 in considering the future management of this tree. It seems a sensible approach. However, my concern with the removal of trees simply because they fall into the U category, is that it is bad news for wildlife and for potential veteran and ancient trees of the future!

 

From looking at the photos I think it is likely that the tree could be retained as a living tree (without work) in the context of the current land use for longer than 10 years.

 

I think you should retain the tree for the time being and reinspect every couple of years. You never know it might succumbe to Chalara! the wound and any associated decay will be the least of its worries then!

[treeseer]

It interesting that you have applied the tree quality assessment from BS 5837:2012 in considering the future management of this tree. It seems a sensible approach. However, my concern with the removal of trees simply because they fall into the U category, is that it is bad news for wildlife and for potential veteran and ancient trees of the future!

...

 

"Showing good vitality - occlusions are sound and look good. Vascular 'piping' has found its way around the wound and looking at the crown shape and extension growth is doing well. A light prune to tighten the crown and 'offer' stability may be otherwise why the need to do anything?"

 

Francis Schwarze, who knows more about wood decay than all of us put together, once showed a class a series of pics of trees (assorted species, soft and hard) with occluded bark around old stem wounds just like that. He asked us to guess the extent % of rot in the cross-section.

Guesses ranged from 20-80%, most around 60%. He then showed us the cross-sections after felling--ALL were <10%, ALL had clearly walled off the wound.

In TRAQ training I heard an apparently uninfected mechanical injury referred to as a 'canker'. I shot up my hand and asked, Where's the infection? The response was a muddled reference about it 'probably in there somewhere'

 

That scheme needs overhauling. We are mis-taught when we are trained to focus on the stem and the obvious. We fail to see the entire tree system when this myopia blinds us.

It's self-delusion to guess what will happen in 10 years. We need to refine our assignments to what we really can know.

Edited February 5, 2015 by treeseer