Grifola frondosa.

[David oakman]

Ihave got grifola frondosa growing on Quercus robur slightly away from the trunk so it is growing off a main root, this is the second year this 300 year old oak has had this fungi. Do any of you exsperts have any exsperience of the decay of this fungi. ps bear in mind a ex is a hasbeen and a spert is a drip under presure.

[David Humphries]

Ola David.

 

We have a number of Oaks with Grifola atm.

 

One particular Tree (120 Dbh) has two fruiting bodies either side of the trunk between butresses, right next to a path.

 

Tested this last week with the Dmp.

Pretty alarming results to be honest.

Especially as although initialy known as a soft rot becoming white rot, literature commonly states that mechanical failure is considered to be rare.

 

Carried out a number of drills. The main test using a 750mm bit @ 500mmm height between the fruiting bodies.

Sound functional wood for approximately 15 - 20 cm depth, then all hell broke loose as the remaining 50 odd cm of drill felt like it was being dragged in by a poltegeist

We're going to be reducing this Tree in a couple of weeks.

 

Tested from t'opposite side and sound wood equated to roughly twice the depth, so leads me to believe there to be a large asymertrical pocket of internal decay.

 

Have attempted to upload the excel data chart, but can't seem to resize to post, any ideas chaps.

 

Going to test another Oak tommorow which is hosting six seperate brackets, could be interesting.

Stay tuned............

 

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[David oakman]

Nice one david keep me posted on your results. i am lucky in one way that most of my trees are private and the owner and me are the only people who normally go to them so they are left to live as they want to. But in the front park the public are in all summer so things have to be done right so i try to balance safety with keeping the old trees but it is becoming very hard to keep them.

[BatiArb]

Ola David.

 

We have a number of Oaks with Grifola atm.

 

One particular Tree (120 Dbh) has two fruiting bodies either side of the trunk between butresses, right next to a path.

 

Carried out a number of drills. The main test using a 750mm bit @ 500mmm height between the fruiting bodies.

Sound functional wood for approximately 15 - 20 cm depth, then all hell broke loose as the remaining 50 odd cm of drill felt like it was being dragged in by a poltegeist

.

 

 

 

Does not sound bad to me, I would question if it was even worth reducing.

 

I also would not have chosen to drill such a tree. Grifola presents a root decay progressing to the base of the trunk, which is not something that can be accurately assessed by sticking a drill into the tree. Not to mention the potential for causing more damage and actually enhancing the progress of the decay into areas where it would not actually have been able to advance to.

 

I believe drilling should be a last resort to confirm findings of non invasive assessment methods that indicate advanced decay that appears to limit management recommendations to either heavy reduction or felling. In such circumstances the decision is likely to be when the tree is removed rather than if.

 

Marcus and I have undertaken a number of root investigations looking at Grifola and it appears to be a deep root decay that affects the dysfunctional remnants of the taproot and lower root system no longer used by the mature tree as a means of support.

 

I believe that Grifola on oak performs a similar function to Meripilus on beech trees, but is much less invasive when it comes to progressing into the lateral root system. In fact it appears rarely on lateral roots and almost entirely confined to the dysfunctional centre of the trunk base and old root system.

 

I have a photographic report of a detailed investigation that Marcus and I completed on an oak with fruiting appearing adjacent to two buttresses on opposite sides of the tree. However, it is too big to post on ArbTalk, so please e-mail me direct on [email protected] and I will send it to you as a pdf (please not it is over 5 meg is size due to the number of photographs)

 

Following this investigation we were not inclined to recommend any work to the tree, even though it is growing in an open location and exposed to lateral wind loads accumulated across open fields.

 

This is just another example of why we need to broaden our scope of understanding and appreciation for how fungi and trees work together in a positive partnership that can prolong the stable life expectancy of many trees.

 

In such circumstance the removal of living foliage can actually create problems where there were originally a natural balance within a dynamic ecosystem evolving over the long lifespan of the tree.

 

We are all to frequently too quick to condemn trees based on a moment in time that is a fraction of their lifetime.

 

In human terms, we would not condemn someone for having a bad day or even being laid up with the flue for a week or so. The same timeframe in tree terms can be several years.

 

It is essential that we respect the slow living processes of trees that evolve over decades and involve a diversity of cohorts that exist in harmony with them !

[Steve Bullman]

andrew, if you'd like to email it to me i can host it on arbtalk

[Bundle 2]

Nice one.......

[BatiArb]

That’s great, file is on its way to you.

 

It was an interesting exploration into the rooting environment of this tree and as you will see from the photographs, at times, it was almost a case of arboriculture meets archaeology. Well at least in the methodology used by Marcus to excavate around the fungal fruiting podium, or what we called the mycelial ‘tuber’. (I on the other hand went in like a typical arb determined to play with his toys, so I took care of the soil around the buttresses with the AirSpade.)

 

An extension to the series of photographs covering the investigation is the series of drawings I have attached below, these are an illustrative example of how the root of a mature tree such as an oak can actually become stronger through its partnership with the fungi that is decaying it.

 

Yes I know that implies some form of acknowledgement or communication between the two organisms, but who are we to say that this isn’t possible.

 

Again baring in mind that the progression illustrated below occurs over decades and the complete process could take a century or more in an oak tree, this is something that I have observed on a number of trees at different stages of the cycle.

 

This is also something that may only really occur at the crossover between the trunk and the main root system, in the section we call the buttresses. This is very well defined within the oak tree that is the subject of the investigation for Grifola. The buttresses subdivide and diversify into smaller lateral roots almost immediately below ground level, and the buttresses on this tree were well advanced on the cycle, which was made possible by the presence of Grifola.

 

The subdivision of the lateral roots from the buttresses in this way is something that I now consider characteristic of mature oak trees like this one, and have also observed on many other trees of different species.

 

Now the point with the progression illustrated below is that the tree ends up with a structure that is far stronger than it started with, and in a form that could not have been achieved if the fungus had not decayed and effectively removed the old dysfunctional section of root.

 

The other characteristic that should be observed in this tree and others of a similar age/maturity is the flair of the buttresses, which increases the structural footprint of the tree, spreading its load over a wider area of ground. In doing this it appears to reduce the load expressed onto the lateral root system and this is where the idea of the traffic cone analogy becomes most apparent.

 

Again this is a feature I have observed on numerous trees of different species, although it appears most common on species such as Oak, Beech and Maple.

 

Regards, Andrew

Root BiomechanicalOptimisation.pdf

Optimisation.pdf

[David oakman]

Andrew i have got a postcard of yours on my office wall it is a branch with a split and a pipistrelle bat in it cool. thanks for the griffola stuff very good david.

[David Humphries]

Does not sound bad to me, I would question if it was even worth reducing.

 

I also would not have chosen to drill such a tree. Grifola presents a root decay progressing to the base of the trunk, which is not something that can be accurately assessed by sticking a drill into the tree. Not to mention the potential for causing more damage and actually enhancing the progress of the decay into areas where it would not actually have been able to advance to.

 

I believe drilling should be a last resort to confirm findings of non invasive assessment methods that indicate advanced decay that appears to limit management recommendations to either heavy reduction or felling. In such circumstances the decision is likely to be when the tree is removed rather than if.

 

 

 

Thanks for the input Andrew.

 

Eerily. I was programmed in to do the reduction on this Oak today, saw your post this morning and decided to hold back.

 

It's understood from reference, that Grif only attacks disfunctional old wood, all be it root or basal trunk.

 

But after Vti, nylon hammer, then finally deciding on the Dmp, (no access to therm yet) I am perplexed as to what, if not Grif, is responsible for the

asymetrical tension side internal decay, recorded @ 50cm height.

No other fungi species have been noted on the trunk.

 

With path and lodge within falling distance, I will be reprogramming this tree in for a 10% sail reduction, which will help mitigate and reduce wind sail effect coupled with the adjacent south/west canopy comp haloed, will allow retrenchment, with future further reduction to take place (3-5 yrs) after regen appraisal.

 

Location is Highgate woods btw.

 

Second shot does not show the desicated brackets which were between the two outer root butresses.

 

 

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[Bundle 2]

2 nd shot is tension side....? and does it correspond with first view atall......