Managing Trees with Decay & Dysfunction

[David Humphries]

Had a closer look at an oak today for a colleague.

Its a wood edge tree that sits next to a busy north London street & a well used internal woodland path.

 

We'd carried out a 2m height reduction about 8 years ago.

 

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[David Humphries]

Had a closer look at an oak today for a colleague.

 

Above ground biomechanics included vertical scar tissue 60cm apart running

up the tension side of the trunk to a height of approximately 2m.

 

We listenend to the trunk/buttressess with a nylon hammer and discovered that the path side trunk face sounded delaminated.

This was then confirmed via resistograph drilling that showed a drop off (2cm void) after 20cm.

 

We felt that this presented itself as a hazard beam (crack) much like Herr Matthecks classic drawing

 

 

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[David Humphries]

Due to the delamination we took the opportunity to have a look below ground to see what the root connectivity was like with this particular part off the root crown.

 

Not suprisingly the front buttress section had discontinued rooting some time ago but younger substantial latteral roots had developed inpart to compensate the loss.

 

it turns out (having bumped into a local font of woodland lore concerning this particular site) that the tree had taken a substantial load during the 1987 gale which resulted in the split.

 

 

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[kevinjohnsonmbe]

These were taken from the inner surface of a hollowed out horse chestnut

 

 

[ATTACH]175438[/ATTACH]

[ATTACH]175439[/ATTACH].

 

Much appreciated David! Been reading since Sunday!!

[David Humphries]

Not sure if these two chestnuts have been posted in this thread before or not.

 

The one on the left has Rigidoporus ulmarius and the one on the right has a significant buttress dysfunction with associated decay.

 

They both received heavy canopy damaged during the '87 & '91 storms.

 

They've been previously worked/reduced three times to my knowledge, at the time of the storms and again in about '02 and '10.

 

 

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[David Humphries]

.....

The one on the left has Rigidoporus ulmarius and the one on the right has a significant buttress dysfunction with associated decay.

 

After carrying out sounding and Resistograph tests we're comfortable with their ongoing management.

 

Both have received further 2m reductions across their canopies to reduce sail whilst maintaining significant amounts of buds.

 

 

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[treeseer]

Seeing the quality of this work is very inspiring!

 

Could you please post the Resi strips? We have had some overreactions to blips and bumps, and questions about shell walls. Customarily, seeing 4" or more on mature oaks indicates great structural strength.

[David Humphries]

Could you please post the Resi strips?

 

 

here are the readings taken at 50cm height from where the resistograph is sited in the two images above Guy.

 

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[Nick Harrison]

Trying to remember if these were the 2 on sandy heath?

presumably there was nothing too alarming at the base hence just the 2 readings?

Can't remember what the condition of the canopy was, was there any thoughts about using the drill elsewhere in the tree?

[David Humphries]

Trying to remember if these were the 2 on sandy heath?

presumably there was nothing too alarming at the base hence just the 2 readings?

Can't remember what the condition of the canopy was, was there any thoughts about using the drill elsewhere in the tree?

 

Alright Nick, hows life in TO world now that you've semi retired the harness?

 

yes, these were the two chestnuts that you climb inspected about a year ago.

 

We carried out a drill at all 4 cardinal points at the base of each tree.

 

The one with the Rigidoporous read ok (in terms of residual wall strength) as seen in the first reading in the previous post.

 

The one with the decayed buttress was fairly alarming where we drilled it through the dysfunctional section as expected, but that was literally just that one buttress and by sounding the tree appears to be compartmentalising this dysfunction. The other three readings on that tree were fine.

 

Having had you prod it when you were up there and Michal having a good look whilst reducing it, we didn't feel that it required drilling anywhere else.

 

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