Thermal imaging its here to stay

[BatiArb]

 

On a seperate subject, investigating sound wood is good, but is this not the same as investigating not sound wood (ie decay) and seeing what's left?

 

 

 

 

Not exactly.

 

The point is that PICUS is limited because it only really identifies different grades of decayed wood or cavity. The user is then left to consider the remainder as 'sound' wood, but there is no way of knowing how much of this so called 'sound' wood is actually functional.

 

Sound wood may or may not be healthy from a trees point of view. After all the wooden chairs or tables in our houses are made of sound wood. A tree requires its trunk and branch wood to be more than simply 'sound'.

 

The point is with thermal imaging is that it uses heat as a tool to allow us to observe functional wood within the tree. This is to say the volume of the trees structure that can hold water.

 

It could in fact be used with a PICUS assessment to map out the proportions of the trunk that are cavity, decay, sound and functional. The PICUS allows the identification of the first two, with thermal providing the final and you can then work out what is left.

[BatiArb]

Not exactly.

 

The point is with thermal imaging is that it uses heat as a tool to allow us to observe functional wood within the tree. This is to say the volume of the trees structure that can hold water.

 

.

 

Now to elaborate on this point.

 

The thermal tree assessment enables to observation of the volume of tree currently holding water. This is to say that it is possible to observe trees that are in drought stress due to a recent period of dry weather.

 

Drought stress presents a very clear characteristic thermal signature, with concentrated cooling at the base of the tree. This can be as a result of site issues, in which case other trees will be exhibiting similar symptoms, or it could be because the tree itself has incurred injury that has put it into an impact drought stress.

 

The image attached is of a tree that is suffering from drought stress, but this is impact related because it has recently undergone pruning, which removed a large number of basal stems (epicormic growth) and its roots were exposed due to adjacent wall repairs.

 

The concentrated cooling at the base of the trunk and the steep temperature gradient between the base and the upper trunk is the characteristic symptom.

[arb culture]

Now to elaborate on this point.

 

The thermal tree assessment enables to observation of the volume of tree currently holding water. This is to say that it is possible to observe trees that are in drought stress due to a recent period of dry weather.

 

Drought stress presents a very clear characteristic thermal signature, with concentrated cooling at the base of the tree. This can be as a result of site issues, in which case other trees will be exhibiting similar symptoms, or it could be because the tree itself has incurred injury that has put it into an impact drought stress.

 

The image attached is of a tree that is suffering from drought stress, but this is impact related because it has recently undergone pruning, which removed a large number of basal stems (epicormic growth) and its roots were exposed due to adjacent wall repairs.

 

The concentrated cooling at the base of the trunk and the steep temperature gradient between the base and the upper trunk is the characteristic symptom.

 

I'm sorry, ut I'm just not convinced by your picture on its own. The temperature gradient could be due to all sorts of things other than what you suggest.

[arb culture]

Not exactly.

 

The point is that PICUS is limited because it only really identifies different grades of decayed wood or cavity. The user is then left to consider the remainder as 'sound' wood, but there is no way of knowing how much of this so called 'sound' wood is actually functional.

 

Sound wood may or may not be healthy from a trees point of view. After all the wooden chairs or tables in our houses are made of sound wood. A tree requires its trunk and branch wood to be more than simply 'sound'.

 

The point is with thermal imaging is that it uses heat as a tool to allow us to observe functional wood within the tree. This is to say the volume of the trees structure that can hold water.

 

It could in fact be used with a PICUS assessment to map out the proportions of the trunk that are cavity, decay, sound and functional. The PICUS allows the identification of the first two, with thermal providing the final and you can then work out what is left.

 

I'm not getting your point. The sound wood in a chair makes it structurally capable of holding a person and the sound wood in a tree can help a tree hold itself up.

 

Most people just want to know if their tree is going to fall over or not. I know there's no point in asking this because we'll just go round in circles, but I optimistically ask - how does TI show whether or not a tree will fall over? (or have x posssibility of falling over if you prefer).

[arb culture]

Sorry, I think I've got it now. You're not knocking PICUS, but you are saying that FCIR is just another tool in the box which can shed some more light on some issues.

 

I agree.

[Yorkshireman]

D'oh

 

theres light at the end of the tunnel

[BatiArb]

I'm not getting your point. The sound wood in a chair makes it structurally capable of holding a person and the sound wood in a tree can help a tree hold itself up.

 

Most people just want to know if their tree is going to fall over or not. I know there's no point in asking this because we'll just go round in circles, but I optimistically ask - how does TI show whether or not a tree will fall over? (or have x posssibility of falling over if you prefer).

 

 

Two points here. Sound wood in a tree is not necessarily good. For example dry seasoned wood will be sound, but it is also inflexible and therefore counterproductive to the flexibility that the tree uses to absorb wind loads.

 

Where there is a combination of dry seasoned wood and flexible water filled wood splits tend to form between them, because of the difference in movement when each absorbs a load.

 

With reference to the second point in your posting, thermal imaging does not show whether or not a tree will fall down, any more than any other tree assessment tool. This comes down to the arborist using the tool to assess the tree. It is possible to use statistical systems to assist with this judgement as to the likelihood of failure and whether action is required or not. However, it must be emphasised that there is no tool on the market that will every remove the need for a qualified and experienced judgement made by the arborists using it.

[BatiArb]

Sorry, I think I've got it now. You're not knocking PICUS, but you are saying that FCIR is just another tool in the box which can shed some more light on some issues.

 

I agree.

 

 

Yes, these are all tools which we use and the arborist has the choice to make. How much information do you need to back up the decision on a tree, and what do you need to know about.

 

Every tool has advantages and disadvantages, not to mention using different means to assess a situation.

 

Personally (as I have said before) I do not think looking at decay and cavities is the right way to assess the ability of a tree to stand up or grow reactively.

 

Thermal Imaging is the only tool on the market that enables us to consider the healthy function of a tree's trunk and main branches.

 

PICUS and the TreeTronic can provide a reasonable assessment of cavities and decay in the trunk, but have limited application anywhere else. The methodology of use certainly cannot provide any indication about root decay.

 

Thermal imaging is the only tool that enables the arborist to consider the condition of the roots, trunk and main branch structure in one single assessment.

[arb culture]

Gotcha, but the bit that gets us going round in circles is the bit where the client says, "so is this tree safe then?"

 

I was under the impression that TI was being sold as a product which could give a probabilistic figure as to a tree's likelihood of failure.

 

If you are saying that this is not the case, and that the assessment is based on the judgement of the surveyor, then what is wrong with a simple VTA.

 

For example, in your photo above, what difference to the practical management of the tree did the photo make?

[arb culture]

D'oh

 

theres light at the end of the tunnel