Decay images

[David Humphries]

Those circles running up and down just left of the centre are peculiar. Is that a decay patern, or frass filled bore holes running along the length of the branch? Great find in any case...

 

 

 

Yep, insect frass Kev, no idea what had been in them.

 

 

 

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[David Humphries]

Beech with long colonisation by Ganoderma pfeifferi

 

Succumbed to the decay of the pfeifferi and wind load of the recent storm.

 

 

Francis Schwarze notes that the white rot decay is by selective delignification and that the decayed volumes can have strikingly dark, reddish brown regions.

 

 

 

The decay has spread quite high up the trunk

 

 

This old pruning wound from about 2.5m up has a small bracket protruding and its mycelium is active behind the wound surface.

 

 

 

For more images of the pfeifferi fruit bodies see the galleries in the fungi directory

 

Ganoderma pfeifferi - Bees wax bracket - David Humphries’s Fungi Directory - Arbtalk.co.uk | Discussion Forum for Arborists

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[David Humphries]

Red oak that has 2 separate Ganoderma species colonisations.

 

G. resinaceum first noted about 2007

 

 

 

G. australe first noted 2016

 

 

We've been monitoring the decay progression since 2007, first using an Arborsonic decay detector then more recently by utilising sounding hammer and the IML Resistograph.

 

 

The most recent resistographs have shown that the sound residual wall is down to about 6cm

 

 

The tree had a significant lean over a well used footpath so was reduced/topped in 2010.

 

The tree was retained rather than removed as it is a good habitat tree with cavities in the trunk and main scaffold branches.

 

Seven years on and the decision was made to remove the tree today as the residual wall is too thin to retain.

 

 

The resinaceum decay (which was actual sponge) has been highlighted in red, the remaining white rot is from the australe.

 

 

The decay extended at least 3m up the trunk and below ground level

 

 

 

 

The last resistograph was taken from 2.5m up the trunk.

 

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[Jake Andrews]

Good work David. Thanks for sharing. Looks like the tree did as best it could to contain/out grow the decay but unfortunately lost the battle. Out of interest, at what point will the residual wall be to thin on a reduced tree? Taking into consideration the extent of the reduction as well. Did the target value persuade you more in this case?

 

Jake Andrews

[David Humphries]

Hello Jake,

 

how long is the proverbial piece of string

 

The tree still had good vascular connection from roots to tip and the reiterated canopy was still extending, so we had the option of further reduction.

 

The issue with this tree though was there was no real decay in the upper trunk or scaffolds so the compressive forces of the sheer dead weight of the wood volumes over the path would have led to a basal collapse at some unknown point.

 

The ongoing decay mapping gives us an indication that the collapse point is becoming of more concern with each passing year.

 

Whilst we were there today dismantling the tree, perhaps somewhere in the region of 300 people passed underneath the tree, so yes, to answer your question Target value played a significant role in the removal decision.

 

 

 

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[Gary Prentice]

 

Whilst we were there today dismantling the tree, perhaps somewhere in the region of 300 people passed underneath the tree, so yes, to answer your question Target value played a significant role in the removal decision.

 

 

 

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Maybe you should have put some barriers out:biggrin:

 

 

Sorry, I can't help myself sometimes!

 

Have you measured the actual t/r on that? It would have been interesting, in a less target rich environment, to have it continue to failure.

[sloth]

On a related note, how close year after year are you happy to drill for subsequent tests? And after using this on more than a few trees over several years have you noticed 'post mortem' any localised advancement of decay as a result of the drilling? Obviously host:fungi specifics will affect things, but have you noticed a general pattern? Just curious....

Good post btw

[David Humphries]

On a related note, how close year after year are you happy to drill for subsequent tests? And after using this on more than a few trees over several years have you noticed 'post mortem' any localised advancement of decay as a result of the drilling? Obviously host:fungi specifics will affect things, but have you noticed a general pattern? Just curious....

Good post btw

 

This particular tree has been drilled 3 times in the last 7 years Kevin.

We don't really undertake the German regime of drilling each and every year.

But where we do return to drill we try and look for the previous holes and set the drill 5cm or so above, below or to either side.

 

I don't believe there's been a noticeable pattern of decay advancement due to the drilling, but then we don't often get the chance to do as much post mortem as we would like, as a lot of the trees with known decay end up standing dead as reduced habitat sticks. When these get taken down (or fail) the decay is often total and so advanced that it would be unreadable as to where previous drills have been in terms of breaching barriers and walls. But as you say, different decay potency and different host tree types combine to create a lot of variables.

 

Something of interest today was trying to see (post mortem) if the two very visibly different decay types could be picked up on by the drill in terms of different amplitude signatures. Surprisingly, the pd400 struggled to breach the hardened barrier at the interface between the resinaceum and the australe, (even trying with each of the 5 different speed/torque settings) so the needle kept retracting where it tried to pass through those specific walled areas. This is shown on the graphs where the test hasn't gone the whole 400mm.

 

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Edited March 7, 2017 by David Humphries

[David Humphries]

Maybe you should have put some barriers out:biggrin:

 

 

Sorry, I can't help myself sometimes!

 

Have you measured the actual t/r on that? It would have been interesting, in a less target rich environment, to have it continue to failure.

 

 

As we don't run commercially the access for the public is managed but rarely blocked completely.

There were 4/5 signs out and barrier tape on one of the paths.

We had our new Arb who started this week taking the top down before we felled the trunk, so we're using the job as a calibration exercise for both the climber and the existing team to tune in on efficiency and communication.

 

We didn't measure the actual t/R in relation to the trunk diameter as it was a reduced tree, but if your interested we could revisit the site on passing and get that for you?

 

 

 

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[IVECOKID]

Big old Chestnut.. rotten to the core

 

 

Ste

Edited March 7, 2017 by IVECOKID