Marcus B-T

I know this is blatent advertising and I can feel the e-mail coming warning me about such activities even now, but I am holding an afternoon bash 1 pm till 4pm on the 6th November, at Wimpole Hall, Cambridgeshire, at which I will give a talk about how thermal imaging works and answer any questions/concerns people have. Basically there is a lot of nonsense talked about the technology and it is a chance to hear it from the horses mouth. It will be warts and all and I know you will find it facinating if nothing else. It is too late notice to get sponsorship so there is a small charge £35 to cover some of the costs but if enough people sign up I will throw in some refreshments. Also if anyone has any other questions about tree physiology and tree health I will be happy to answer them so bring your photos etc. My contact details are available at http://www.trees-project.co.uk Regards Marcus Bellett-Travers

Message sent to Private mail area of this site Regards Marcus

If you look at the Beach Road Study, the tree that was felled looked no different to the one that fell down or the others that remain. This can be confirmed by the tree officer because that is why he called us in. The alternative would have been either lots of PICUS and drilling both of which were prohibitively expensive for so many trees and damaging. We found the only badly decayed tree and it was felled, and I think the picture of what was found inside is in the case study. The others were retained so from the point of view of the trees a big success story, firstly the trees that were OK were retained without any invasive methods being used; secondly a very badly decayed tree was spotted and removed. In terms of publications there are lots of publications on trees and heat already out there that confirm what I have already said. I think there is some stuff on coniferous trees in particular on the TEP web site from Bruno Uni also Jim Morrison at Essex has looked at plants and heating for many years. This is, in one sence, nothing new; all I have done is put the pieces of a complex jigsaw together and come up with the answer. We now have independent studies by Giorgio Catena (a well respected thermographer), My self (well respected environmental modeller) and many plant physiologists, physicists and thermographers that demonstrate how surface heat is related to internal changes and defects. I think its time to get off the chat rooms and just come and spend some time in the field. In terms of what thermal imaging can tell us beyond the visual. The extent of cooling of branches in comparison to the mainstem gives an estimate of longevity that can be used to plan work. This cannot be done by eye. The entent of decay in the root plate including the below ground parts can be determined, this cannot be done by eye. The extent of cankering up stems and branches can be determined, this cannot be done by eye, the differention between buttressing caused by movement and that caused by decay can be determined, this cannot be done by eye. I could go on. The point is that there are many many things thermal imaging can tell us and if you wait for me to write it all down it would be years before we get anywhere. Scott F. The challenge is this, come and spend a day with me and you will find out what all the fuss is about but in return you have to write about it on this chat room.

OK as I promised yesterday this is how it works. The tree has a very complex system for heat transport that acts as a moderator of the effects of external temperature. The system is improved by the presence of the vascular system but works even without it because the vascular system is only part of the heat moving system. Therefore, it works in winter and summer. It has to be complex because if the tree relied just on insulation it would not grow in the spring because it would take too long to warm up; and in the summer heat would become trapped and fry the tree. For similar reasons the system has to work when transpiration is low or has stopped because again trees would take too long to respond to temperature. You could not have a system that just used the vascular system because it switches on and off throughout the year and throughout the day making it very inefficient. The whole system is driven by changes in environemental temperature, so that it doesn't matter what the actual temperature is as long as it changes, Which it does every day between dawn and midday and vice versa. Just a point here before I continue, that is why you need the software to calibrate the images, because every day the temperature changes are different and there are difference for some species as well. So, we have a system that moves heat around the tree, but this is not the end of it. The heat dosen't just move up and down the tree it moves in and out of the stem; from all but the most inert heart wood, through the sap wood and vascular system to the surface. So you have both longitudinal and radial heat movement in response to changes in environmental temperature. As this happens you get a heat gradient from the centre to the outer surface, which again if the tree functions well is relatively even. But, if something gets in the way that does not conduct heat well it reduces heat flow so that heat moving to and from the surface is restricted. This causes the surface to be relatively cooler in areas where the heat doesn't move to and from it as efficiently. The closer the surface is to the anomoly the greater the effect. That is why the greatest effect is from cankers at the surface. Decay and cavities have a profound effect on temperature because they heat up and release heat very slowly so there is a big differential between healthy functional tissues and the affected areas. This becomes apparent at the surface because the reduced heat movement to the surface reduces surface temperature. The bigger the volume of decay, the more it alters temperature movement, the more it alters surface temperature. Again to understand it properly you need to calibrate images against environmental temperature. Other barriers such as inclusions, splits etc have localise distinct effects. So with training you can actually differentiate between differt kinds of anomaly. This is why you can use it for decay detection but the emphasis is on detection not investigation or confirmation. None of the decay detection methods can investigate or confirm decay!! In addition no decay detection method can tell you if a tree is likely to fail, this is a matter of the balance between wind forces and static forces applied to the tree on the one hand and the resisting forces of the tree on the other. This MUST be determined by mechanistic or statistical means. I can't think of any publication where decay detection equipment been a directly compared to actual tree failure, i.e. trees where pre-tested and then allowed to fail and quite rightly so since this would misslead people into thinking we have tree failure detection methods, and this would be a nonesence . BUT we have done this as part of the process of checking for incedences of false positives, i.e. the technology says there isn't a decay when there is. We have carried out measurements with IR on over 20,000 trees and around 8,000 of these were either felled or had increment cores taken to confirm the findings. We have had zero false positives and because IR is a direct measurement of tree health this is quite understandable. We have had low incedence about 1 in 3000 false negatives i.e. it looks like decay when it isn't but this is caused by large volume of included rubble or dead/dried wood and we now know what this looks like and so false negatives are very rare. I emphasise that this is decay detection and not confirmation so we always recommend an invasive study before felling but this must be done what ever the method you use for decay detection. We have presented our findings to our peers at conferences in Turin and Coventry and we will soon be publishing our findings in journals but this is a natural process and takes time. We are always glad to discuss our findings and technology. The best bit about thermal imaging though is the fact that because it measures temperature it actually measures the balance between tissues with optimal health and tissues that are sub-optimal, so that you get a balance between the two and an appreciation of how robust the tree is to both the environment but also to any work done to it. Therefore it is much more flexible than just a method of decay detection. Also it looks at the whole system from surface to interior. It does have limitations and we accept this, but it also has a wealth of possibilities. If anyone would care to take the time to see the technology in action and explained in detail this can be arranged all you have to do is ask.

It could be any numbe of organisms or even a combination of them. To get a better idea you need to look further up the stem where the rot may be younger. Out of interest what where the visual symptoms.

OK I've seen what people have written and here are some answers. The first thing that you all need to think is not 'why the surface temperature of something indicate an internal fault' because in thermal imaging terms this concept is nothing new and has been applied to many other applications already and I will deal with this either in a moment if I have time or in another posting. The thing that is remarkable is that a healthy tree has a relatively even surface temperature, because it realy shouldn't. There are so many changes in ambient air temperature, soil tempertaure etc going on all the time that realy the surface temperature should be a mixture of areas with different surface temperatures but it isn't! SO why is this? Well little did we know but trees have a very efficient 3 dimensional heat transfere and transport system. The vascular system is part of this but 'only' part of it and the sap wood and central wood volumes such as heart wood are all part of it. So why should a tree need this? well if it didn't, the growth of a tree would be increadibly uneven and you couldn't have big trees. Cell metabolism including growth is temperature dependent, because trees do not produce heat themselves they require heat from the environment to drive metabolic chemical reactions. To illustrate this think about how slow crop growth is in cool spring weather even if there is plenty of sunshine. So the tree needs to augment and transport environemntal heat efficiently to activate cell metabolism. This is just as important on the sunlit side of trees as on the shaded side, except here there is also the need to disipate excess heat which will kill cells. This is why trees have a very efficient heat tranfere system that moves heat to and from the surface. If we didn't have this then the temperature would not be even, also without it extreme temperature gradients will be set up in side the tree. The gradients set up will cause depressions in surface temperature. Guess what, this is what thermal imaging picks up. The problem is that what we are told and anticipate in terms of heat metoblism of trees is generally wrong. We think of most tree systems in over simplistic ways and forms. Did we realy think something as large and complex as a tree would revolve around simple systems? If it did it would die the day the seeds germinated. Ted Green thinks we are on the dust cover of the book of trees; we havn't even got a publisher to take the book seriously!!!

When we use thermal imaging and we feel that the volume of dysfunctional tissue has reached a crital value we always do confirmations with an increment borer. This allows us to look at actual wood quality and can reveal some suprising things. For example we often find dried and cracked wood at the base of large trees without any signs of decay. If the tree is under a great deal of wind presure this is often quite extensive taking up about 50% of the internal volume close to the base of the tree. Also we now know that Phaeolus schwinitzii (think that's the right spelling) causes wood to dry infront of the area of infection and this can cause branches to be shed particularly in cedar. Of course we are helped by knowing just where to put the borer by the thermal images but I personally cannot understand why anyone would be lulled into felling a tree without an invasive inspection before hand.

Thought you might like to know I have some evedence that bleeding canker on chestnuts has been around for at least ten years its just we haven't noticed it as much. It probably came to promenance as a result of a run of dry summers and it is definately less evident this year after two wet years. Also many trees recover, it generally the stressed trees that do worst and many of the cracks are superficial and don't inhibit the structural safety of the tree There have been some develpments n the Cameraria as well with early trails of a fungal pathogen to the moth Enjoy Marcus B-T enjoy Marcus

Have just posted some responses to Thermal imaging queries etc if this interests you. Regrding comparing technolgies what things tell you are they any good etc. The problem with comparing technologies is it is a bit like comparing knives, forks and spoons. They are all cutlery used to eat food but in different ways. None of the technologies and I happily include thermal imaging in this tell you how decyed wood is. They measure properties of wood that are changed by many things including decay. Thermal imaging looks at wood functionality, how well it performs a physiological function (heat transfer). This is altered by decay and other things as well. Picus measures relative elastic modulus and density of wood which are altered by decay but also other things as well Resistograph measurese relative mechanical resistance which is altered by decay but other things as well. In short they are all tools and it is down to the application and use. This is ultimaetly down to training and experience. Because they are all technologies that measure something that is interpreted as decay not actually decay, then they are are prone to error and missinterpretation. An interesting fact is that the more a technology is used the more accurate it becomes, this is how we got the accuracy of thermal imaging to +/- 2% very quickly. Its quick yo use so we could quickly build up experience and tune the product. Enjoy Marcus Bellett-Travers

We have tried to make the technology as affordable as possible. The only up front payment is the cost of the first two days training is £1500*. Following this, nearly all the licensees training and updating costs are included in the cost of the software licence. TREES PROJECT LIMTED has also negotiated preferential hire rates on the latest thermal imaging cameras with Ashtead Technology (http://www.ashtead-technology .com). Cameras can be hired for around £200* a day but the ore you hire them the cheaper they become. TREES PROJECT LIMITED is a reseller of FLIR cameras (http://www.flir.com) the worlds leading infrared camera manufacturer. We have extensively researched the market for the most suitable cameras and these can be purchased for around £12,000*. Enjoy Marcus Bellett-Travers

TREES PROJECT LIMITED has developed the TREE THERMAL MATRIX SOFTWARE (TTMS) which allows quick calibration of images based on measurements of ambient air temperature. A rigorous process of proof of principle was used to develop the software using images taken from over 20,000 trees from across the UK with destructive sampling and confirmation on over 7,000 of those trees. The software is available on a ‘pay as you go’ licence so that even small volume users can have access to the software. We provide full training. A two day training course followed by a mentoring process that can take up to 1 month but trainees can start to use thermal imaging commercially after the first two days training. The first training day includes an introduction to the principles behind thermal imaging and how to operate a camera. The second day introduces the licensee to the process of taking thermal images of trees and recording data. The mentoring period takes the licensee through the process of image interpretation and is a quality assurance mechanism to ensure licensees have properly understood the methodologies of using the camera, recording images and interpreting data. On completion of the mentoring period, the licensee receives a copy of TTMS and away you go. Enjoy MArcus Bellett-Travers

Thermal imaging has been widely used by more than 50 clients in the UK including more than 20 local authorities (e.g. Derbyshire County Council, Somerset County Council), many large estates (e.g. Blenheim Palace, Woburn Abbey, Windsor Great Park), arboricultural consultants and the general public. Thermal imaging cameras detect the infrared radiation emitted from the surface of trees. This can be used to measure the surface temperature of their stem and limbs. When the wood of trees is physiologically healthy it absorbs and transports heat efficiently. This gives the surface temperature an even pattern, with minor changes associated with bark patterns or the presence of moss and lichens. If something alters the physiological health of the wood, heat does not flow around the tree as efficiently and cooler volumes of wood are created. This causes a temperature gradient to be created and leads to relatively cooler areas at the surface. The more the relative physiological efficiency of the wood is reduced the greater the effect on the apparent surface temperature. Therefore thermal imaging can be used to look at the comparative physiological health and functionality of volumes of wood within trees. The system is highly accurate to within +/-2% and it means that you only use invasive tools when ABSOLUTLY NECESSARY! One interesting thing we have found is that our perception of how likely a tree is to fail is about 3 times too pessimistic, i.e. if someone tells you a tree has a 1 in 250 chance of failing it is probably only 1 in 750 likely to fail. Many things can alter the physiological functionality of wood but the most dramatic effects are caused when fungal organisms invade it and cause the wood to become decomposed. The physiological functionality of wood is also altered by inclusions, splits, cracks and shakes; all of which can be detected with thermal imaging. Both physical and biological damage to larger parts of the root system can also be detected. The heat environment around a tree changes both daily and seasonally which in turn affects the range of temperatures present on the surface of a tree. This means that thermal images need constant and careful calibration so that they represent the functionality of wood. Sunlight is a consideration but is easily worked around as are rain and wind. We have only lost 2 working days so far this summer and sunlight has not stopped us imaging a tree yet. Enjoy Marcus Bellett-Travers

I can answer your questions re thermal imaging Marcus Bellett-Travers