Decay Detection

[Legit_Arborist]

What methodology for decay detection do you utilize in the Commercial marketplace? Does anyone have any experiece using PiCUS Sonic Tomography? There is a new completitor for the PiCUS Sonometer called Fakopp...I'll mispell the name I'm sure...Does anyone have any experience with this unit? We are interested in utilizing this type of decay detection at our campus and am interested in feedback.

 

[treeseer]

i use a mallet and noninvasive probes, mainly. Stem decay is an exaggerated aspect of tree risk assessment.

See the entire tree!

 

[isaaccarlson]

you have to read the whole tree. look at the roots, bark, branches.....there are times when you have to make a judgement call. I made one a couple days ago. It was a maple that had 3 main trunks joined at the ground. One of them looked kinda funky....it was leaking sap all over so I looked the whole tree over. There was an ant mound at the bottom of the tree and the soil was all moist. Some of the branches were dead/dying and it looked like it might have some center rot. I talked it over with the HO and he said it was up to me. I decided to take the funky looking one down and read the stump. Turned out they were all center rotted and the ants were coming up from what was left of the roots and feeding on the sap. The tree was removed. There are also a few oaks/cherry that need to come down due to center rot/bug infestation.

 

[tree md]

Sounds a lot like this tree:

I've shown this to treeseer before and we've discussed it. I had some history with this Red Oak. I had deadwooded it before and treated it for an ant infestation. I also cleaned the rotten wood out of the wound. The HO painted the wound later on without my knowledge. When I came back a year later it had seriously deteriorated. I think painting the wound had a lot to do with it. I cleaned it out again and advised HO not to paint the wound. Finally it deteriorated to the point you see in the pic. I recommended removal. The tree was compromised but I sounded it out with a mallet, looked it over and assessed it as safe enough to rig from. Rigged some pretty large pieces too.

 

[isaaccarlson]

looks like you have some fungus in there too. If it were my tree It would come down before getting weaker. IMO. Not good to have a possible blow-over.

 

[pdqdl]

I think you will find that the tree maintenance market does not support paying for an expensive machine that provides marginally improved understanding of a tree's condition.

Government institutions and research facilities perhaps, but it would be a very specialized tree assessment business that could justify the expense of such a machine. I suspect that the only time it would be necessary is when you are planning on dealing with lawyers and the courts.

After all, mallets are pretty cheap. With experience, they probably do about as well. Even a Tanaka gas powered drill motor for increment boring would be cheap by comparison.

 

[Legit_Arborist]

I think you will find that the tree maintenance market does not support paying for an expensive machine that provides marginally improved understanding of a tree's condition.

Government institutions and research facilities perhaps, but it would be a very specialized tree assessment business that could justify the expense of such a machine. I suspect that the only time it would be necessary is when you are planning on dealing with lawyers and the courts.

After all, mallets are pretty cheap. With experience, they probably do about as well. Even a Tanaka gas powered drill motor for increment boring would be cheap by comparison.

I would agree with you. I think the sounding method is obviously very inexpensive and simple...but not always reliable...even if you have a good deal of experience using that method.

The reason I started this thread was because I was curious to get feedback on anyone who had used the Tomography. The digital decay detection instruments are very fascinating and there is one in particular being developed by a young guy out in Holland...I can't remember the name of the device. It's very similar to the PICUS Sonometer but it's name is something like Fakopf. I've seen it in action before and it's really impressive what kind of imagry you can produce.

I understand that most commercial outfits won't find the benefit of using these tools because, let's face it, it's hardly a commercial need. But the right customer or firm that has mature landscaping, especially if the arborscpe is diverse, may find tools such as these very useful. Although, the majority of the time these tools aren't used unless there is some form of consultation by an RCA or BCMA required. Hardly a commercial normality.

 

[Legit_Arborist]

Sounds a lot like this tree:

I've shown this to treeseer before and we've discussed it. I had some history with this Red Oak. I had deadwooded it before and treated it for an ant infestation. I also cleaned the rotten wood out of the wound. The HO painted the wound later on without my knowledge. When I came back a year later it had seriously deteriorated. I think painting the wound had a lot to do with it. I cleaned it out again and advised HO not to paint the wound. Finally it deteriorated to the point you see in the pic. I recommended removal. The tree was compromised but I sounded it out with a mallet, looked it over and assessed it as safe enough to rig from. Rigged some pretty large pieces too.

This is a perfect example of why I'm interested in the advanced devices for decay detection. There was obviously severe branch codominance prior to the limb failure and the arborist probably could have supposed some degree of internal decay...most likey to the degree that sounding would not have been able to detect. Even if the arborist wasn't paid to do an investigation using these tools, one who owned the device could have done the test on their own to confrim or negate their assumptions of potential limb failure and evaluate risk.

As much as I think the sounding method has it's place, I don't think it would have been able to provide the same level of predictive information that a digital imagery device would provide.

 

[Legit_Arborist]

i use a mallet and noninvasive probes, mainly. Stem decay is an exaggerated aspect of tree risk assessment.

See the entire tree!

Treeseer, why do you think that. That sound like an opinion whereas my experience would suggest that stem decay is extremely important to be able to determine both for the safety of climbers and for the evaluation of risk for potential targets.

Not attacking you or trying to be confrontational...just honestly curious as to why you think it's an exaggerated part of risk assessment.

 

[treeseer]

Treeseer, why do you think that. That sound like an opinion whereas my experience would suggest that stem decay is extremely important to be able to determine both for the safety of climbers and for the evaluation of risk for potential targets.

Not attacking you or trying to be confrontational...just honestly curious as to why you think it's an exaggerated part of risk assessment.

Stem failures account for <10% of tree failures, based on 2 very good studies. Yet stem wall thickness is an obsession among some assessors, who overlook roots and branches, and also overlook strength gain factors and mitigation options.

Confronting is cool if it's about opinions not personalities.

I'd buy a tomograph if i had the cash. I know lots of folks with resistographs.
Next assessment tool I buy will probably be a Shigometer.

 

[ddhlakebound]

Treeseer, why do you think that. That sound like an opinion whereas my experience would suggest that stem decay is extremely important to be able to determine both for the safety of climbers and for the evaluation of risk for potential targets.

Not attacking you or trying to be confrontational...just honestly curious as to why you think it's an exaggerated part of risk assessment.

When a stem is decayed inside, but intact outside, a decay column which is small enough to be missed by sounding is causing a very insignificant strength loss in the stem. We can quantify that strength loss, at the price of invading the stem (or $$$ tomography). If the stem is decayed enough that strength loss is significant, it will be easily noticed by an experienced ear.

If a wound or canker allows us access to the decay, we can more easily quantify the strength loss with non invasive methods.

Most failures I've seen occur in bad branch unions, overly extended limbs, and root plate failures. I can only remember 2 times in my limited experience I've seen a column of decay in a main stem as the cause of failure. There are probably a few I'm not remembering.

That's why it's an "exaggerated" part of hazard assessment.

When it comes to dynamic rigging, that quantification becomes much more necessary, but you're already in the removal process and can invade the stem to quantify then anyway.

Are stoplights and street lights kept in the air by a solid metal pole? Why?

 

[ddhlakebound]

This is a perfect example of why I'm interested in the advanced devices for decay detection. There was obviously severe branch codominance prior to the limb failure and the arborist probably could have supposed some degree of internal decay...most likey to the degree that sounding would not have been able to detect. Even if the arborist wasn't paid to do an investigation using these tools, one who owned the device could have done the test on their own to confrim or negate their assumptions of potential limb failure and evaluate risk.

As much as I think the sounding method has it's place, I don't think it would have been able to provide the same level of predictive information that a digital imagery device would provide.

To the first part, why? The original tri-dom stem would have been easy for a noob to see as an eventual failure point. Cabling would have likely prevented the failure, and kept 3/3 of the tree for much longer than 2/3 were allowed to stand. Simple. Cheap. (in comparison) Effective. RW Experienced based.

How much hands on tomography have you done? Does any of that tomography include disection to verify or nullify the conclusions you drew from the machines output? Don't get me wrong, it's a great tool. I'd love to have one, and learn to use it effectively. But in the end, it's just a tool, and the working arborist holding it MUST be able to accurately interpret the readings. (And that takes usage and disection to verify findings until an experience level is attained.)

But I don't expect you to get that, as you've been nothing but a giant poo-pooer of us working guys who don't know nuthin bout dem dere trees.

 

[treevet]

Decay readings are all well and good................if decay was a static entity. Decay, like rust, never sleeps. This is why in conjunction with a decay assessment an identification of the pathogen and its virulence both in intrinsic terms and in relation to its favorable or unfavorable environment is necessary through culture or fruiting body identification or whatever. The whole story, as mentioned above involving other variables must be considered.

 

[derwoodii]

I have used Picus often enough to be positive of its benefits. A good mallet is 1st best tool in your kit. But for analysis that can be seen and understood by your customer or lay persons the picus gives a good picture in color of a trees trunk section showing sound vs decay wood.

 

[jefflovstrom]

I cannot rep any of you guys- gotta spread it around-But you have provided valued info to a guy that says 15 years in a research lab. Interesting.
Jeff

 

[treevet]

"Diagnosis and Prognosis of the Development of Wood Decay in Urban Trees", by Francis Schwarze is a good read (didn't say easy.....or cheap) if you really want to arm yourself with knowledge about this subject.

 

[ozzy42]

Sounds a lot like this tree:

Aahh ,That's just surface rust.I could get that out with a buffer.

 

[treemandan]

I cannot rep any of you guys- gotta spread it around-But you have provided valued info to a guy that says 15 years in a research lab. Interesting.
Jeff

Man you all seem to have that guy in the red!

 

[derwoodii]

"Diagnosis and Prognosis of the Development of Wood Decay in Urban Trees", by Francis Schwarze is a good read (didn't say easy.....or cheap) if you really want to arm yourself with knowledge about this subject.

Your right not easy read at all. I spent a week with this chap learning his craft. What a interesting bloke an English German who plays the the violin. Then relates how decay and wood growth affects/improves the sound quality of wood instruments.

 

[treevet]

Then relates how decay and wood growth affects/improves the sound quality of wood instruments.

He and Shigo would have much in common.