Marcus B-T

The main pollutant is nitrogen, you are only allowed to apply 250 kg h/a in any one year, even if it is a localised appliction. If your compost is from an urban area you may also fall fowl of limits on heavy metal applications. This might seem a bit harsh for mulching trees, and at the moment probably is, but if we start mulching trees in larger amounts then collectively it would have a significant impact on soil and water quality. It all has to go somewhere and invariably it goes down. In terms of the nutrient content in a wood chip pile this is a 'how long is a piece of string' question. The N output would be determined by the source material, the size of the composting heap, the degree of aeration and the outside temperature. For full stabilisation would would need longer than 6 weeks for a ststic pile and even so turning would be recommended or at least removing the top layer and recomposting it, only using the lower layers that have been allowed to compost. The best thing is to send off a sample for analysis, it used to work out at about £30 . This will then give you the definative answers you need.

With some organic composts you will be adding a large amount of freely available N (not good for trees, and you could be polluting local aquafers) also there are regulations on total N applications. Also you can taylor the application to the nutrient ballance. Also 5% of what? What is actually needed for most trees is to establish an 'O' horizon to reflect what would be seen in a forest soil. On a % basis this would be more than 5% of the vadose layer but would be less than 5% of the total occupied soil depth. This is why mulches work, they reduce competition for water and nutrients but they also reflect the natural delivery of nutients to trees (and perhaps water as well). The problem is that to establish a 'natualised' 'O' horizon you can't put all the organic matter on in one go and also you need to know when you can reapply. Also I am not convinced by the 5% figure the references trace back to what is seen as optimal for grassland/ agronomic situations and don't tie in with trees.

One more thing, I have been comissioned to produce an application rate calculator for organic waste but it could equaly be used to calculate application rates for composts to trees.

I didn't g to the Mattheck seminar so I don't know how much of this was discussed or how much people already know about this. I will only be able to give an intro at this time, just too busy with other things today, and it is Sunday, but I will get round to a longer answer at some point. The penetrometer is not a measure of bulk density, it is a measure of penetration resistance (this in itself is useful info), the realtionship between compaction, bulk density and mechanical resistance is complex but you can estimate bulk density from mechanical resistance, the main problem is the realtionship between resistance and soil water content, this relationship varies with soil texture and to a lesser extent structure. Also pororsity can have an effect and also varies with the type of compaction force applied. This is all before you consider the errors form hitting stone or tree roots. The direct measurement is to use bulk density tins as described above, but this is time consuming and also you usually need at least 12 hours dying time and it can be up to 36 hrs. There are soil coring apparatus as well. Form what I understand from David he is just trying to do a demonstartion of change so as long as he measures like with like, i.e. the same area with the same moisture content, then this is OK, however with some soil types you may not see the changes in penetrometer resisitance until there has been big change is soil conditions. Regards M B-T

Fantastic post (being serious here). Point one is that it is not £150 if you are a local arb working within one region it is only £15 and you get the data for your local area, if you are a national outfit then you pay £150 for the full UK package. Also it's free to LA's. It's like this (and I speak from the experience of my self and a number of other highly experienced arb consultantants here who asked me to come up with this, they have been testing it and continue to test it by the way), This does not replace VTA or the assessment procedure, it uses the data you gather to give you a robust statistical outcome, now if you take that to court then it is better than any expert opinion for a start. It basically says that when I compared the tree I am looking at to the trees around it then it was no different to almost all the trees around it. They are still upright and have been so for as long as any one can remeber so why should this one be considered any different. This is a very powerful argument and ranks even higher than the argument I used VTA and identified a defect or not as the case may be. So that is the legal stuff covered. Just to reiterate at this point that VTA or some kind of visual assessment is the starting point. So why did the experts ask me to produce this. Well two issues. The first is if a tree is recently exposed by a tree removal or a tree removal is planed. Question then is are the remaining trees robust enough to withstand the recent exposure. This is a very difficult thing to judge by eye and the common outcome is that some of the remaining trees are canopy reduced in some way. So if you have a robust tool that demonstrates that the trees are no different to the maority of the population then the need for reduction is removed (robustly and scientifically). Next scenario is that there is a moderate amount of decay found at the base of the tree using PICUS, resistograph or thermal imaging, or a mallet if you wish (take your pick here). The question then is has the tree naturally retrenched in response to this, is like the majority of the population and therefore no work required; or is it disproportionately tall for its DBH and therefore potentially a candidate for canopy reduction. The ultimate test to this system is this, do we see large numbers of trees falling dwn every year, answer no. Why is this? well accoriding the the experts (Matteck, Wessolly, Clark, etc, etc) the structur of some trees predisposes them to excess forces that cause them to fail. How do you find out which ones are predisposed? Measure them. If you measure enough you have a description of the population, statistically you look to the extream of the relationship till you find the members of the population that are predisposed. Once you have this, you have a model that tells you explicitly where the limits are. Then you measure and individual in that population and compare it to the model. SO you are probably wondering what the catch is now, well about 30 sleeples nights gathering all the data, and also the model is only valid for the population you have measured, so each population needs to be described in turn, a big job that has taken me about a year to do. I am working with some of the eminant abs I refered to earlier to put together a science bit to explain it in more data. By the way id you think the model cannot work then you will have to throw all your Matteck and Wessolly books away sisnce they advocate this approach.

The program uses the realtionship between tree height and stem diameter at breast height to determine the likelihood that a tree will fail see the link below for just some of the huge amount of science behind this. Tree Consult There are two ways of using this relationship, 1. is to gather information of individual trees and try to calculate the mechanical strength it might have using a complex model the problem with this is that you need some pretty acuarte measurements of the degree of sheltering, the wood strength, etc, etc. 2. is to gather the actual height and dbh data for a large sub-sample of the trees you want to assess. So you measure the height to dbh ratio of around 2000 tress in a city, and then you have a description of the population against which you can compare an individual tree. This is a time consuming process but is a highly robust way of doing it. Once you have this data you can then look at the influence of stem thining (decay) and stem dying and splitting (a form of dysfunction). You then have a universal data set for your city. With 2000 trees it gives you confidence upto 95% of the population, but you can then build on this database over time and increase that up to 99% etc. So how did I manage to create data bases for so many cities in the UK? Easy, I used Google Street. Since you only need a ratio to start with you can take the data straight from the images. It still takes a fair amount of time and dedication but now I have the data it can be constantly improved up. So what is the big deal with this? Well it means if you have a tree that becomes exposed, you have a robust way of deciding A) it is like most of the rest of the population so no need to think it will fail, B) it is like 5% of the population that are at the limit of the ratio so time for further analysis. The same goes for trees with basal decay. What does it mean? It means that far fewer trees require work, and we have greater confidence in our decisions. It is also exactly what we already do with VTA we look at the size of the tree and the amount of decay (for example) and then decide does it need reducing or not?

I have been persuaded to offer the height vs dbh programme free to local authorities. You will still need to register by either emailing your details to [email protected] or sending a private message on this web site to marcus b-t.

The full version of my height vs DBH evaluation software is now available to down load on this site a percentage of sales goes to Arbtalk. The full version (all 30 plus UK cities) is £150 + VAT but for the small guy who just wants to evaluate trees in his local area you can have two cities for £15 VAT (this covers the cost of setting up your registartion for upgardes). The calulator will tell you the significance of the height to DBH ratio for newly exposed trees and also will evaluated the significance of the realtionship for decayed trees, i.e. is the tree just like every other tree or is it significantly different. This is a realy robust way of dealing with the difficult issue of does a tree need to be reduced or not.

Something I have been banging on about for the last 5 years is the fact that bleeding canker on HC has been around for at least 12 years, and that it was only following a period of realtively dry years that anybody noticed it. Also there is a strong correlation between trees already compromised by internal decay of physical damage and the worst affected trees. It seems that since we have had two relatively wet summers and also perhaps the cold winters halp here as well, that incidences of HC bleeding canker are well down on what we might have thought as normal. So should we be looking to alter the cause and not treat the symptoms?

I have used vta since some of the first papers came out and still continue to use it. I did use the phrase "may be unclear" and i would only give the broad outline information as above based on a photo. The issue is that if a branch is removed today then all that it caused becomes historical today. Without a site visit this is uncertain.

Google destructive wood testing, telegraph poles. They are available still on the net I used one in some research trouble is that you only find decay near the surface or you drill quite large holes in the trees, which sort of defeats the object.

On a different note I saw some fantistic structures recently where trees blown over by storms where re-errected and held upright with tripods, not cheap though. Marcus

Some info: In terms of oaks and types of failure, with Q. robur the most likely type of faiure with this kind of tree is limb failure. If it doesn't have any large and long limbs on it with cavitated areas behind the upper part of the limb union there is unlikely to be a failure. If the tree still has a decent canopy on it in this state it indicates good functional wood in the root systema and up the stem. The rate of retrenchment is key in these cases, what you need to avoid is these larger limbs, height is less of an issue, since you have already indicted it is reduced agianst DBH, and it is in a sheltered location. It may be that there is no reason to do any work. The problem with the attributes seen with VTA is that they may be historical and happened when the tree had a larger canopy, but without a full picture or a site visit it is very hard to say. When it comes to Q. petraea and also some of the upright hybrids it is different thes often do retain a thicker canopy that becomes an issue and causes basal failure once you get to 80-90% basal dysfunction. They are less predictable as well since they tend to have a fuller canopy and look very healthy with a fuller canopy but this makes them more prone to basal failure. What amazes me is the small amount of functional wood Q. petraea can get away with. Regards Marcus

Can you post a picture of the whole tree please and an idea of dbh i am thinking there is on budget to keep it so lowest cost option?

Have been thinking about this some more and magnus you have not said exactly what you plan to do but penetrometer results are very variable if you are looking o show improvements in bull density and porosity there are better ways of doing it

You should have a chat with the soil physics group at Rnthamsted Experimental Station before you do or buy anything

Just had confirmation from Julian on cost etc. You will be able to download the software for free, the training course is as follows 22nd June. The venue is likely to be: Don't Get Lost! Use Our Directions to Inglewood Manor - Cheshire, UK Cost ceilinged at £180 + VAT exc. the workbook or £205 inc. workbook training. Cost will reduce if numbers exceed 8 delegates.

I have finished the last tweeks of THREATSXL the MS Excel version of THREATS and it will be available very soon at Expert Arboricultural Consultants | Forbes-Laird Arboricultural Consultancy You can download the paper version of THREATS for free at this site and lots of other good free stuff as well. As I understand it THREATSXL will also be free but you have to register to get a copy. Julian is running a training course in June (25th I think) in Chester on THREATS which will include THREATSXL. Details from [email protected] I am now working on a set of tools to compliment THREATS and other risk assessment systems. Regards Marcus

Some of the places i have data on are Aberdeen, Edinburgh, glasgow, Newcastle, Teeside, manchester, liverpool, york, leeds, Sheffield, Nottingham, stoke, birmingham, oxford, cambridge, Norwich, Cardiff, bristol, southampton, london(5 areas)

Two vesions one 2007 compatible the other 97 compatible, with a how to in word 2007. I have had to zip them to make them small enough. Marcus excel.zip

I have a program that has height vs dbh info for 30 towns and cities across uk. It is also separated into trees with more than 60% damage at the base. I am making it available at ashareware price so less than £50 a city and i will put a free demo up tonight based on cambridge data

Cheeky lot it is my eye sight and the size of my fingers that are the problem not my technical ability i hope to get some pre-production samples next week.

Sorry doing all this from my new phone so struggling a bit with small keys. It is something you put your phone onto rosy i cannot say more i have a patent application on it but wanted to gauge demand. I want to make it as cheap as possible, but need to cover costs. Sorry about not replying to pm messages not easy on my phone to fortunately maybe the software does have other applications?

The other thing is a software app tip is a low tech physical thing but precision made hence the price i had one made for my own use but son others have seen it and said they want one

Sorry about the typos predictive text and all that. It is a physical add on you need a screen 4.5 cm x 3.5 cm or better i am seeing a mann next week and wont to get retail down bellow £15