daltontrees

A. platanoides 'Drumondii' it is. The Louis Frere is variegated but in a different way, not the margin but whole interveinal sectors. Still no more shots at the Battersea Park tree? The more I stare at it the more I see a lady in a tweed dress and waistcoat. I think I need more sleep.

And if you wish something to ponder in the unlikely event on not being mentally fecked down-under, here is a wee thing that troubles me about quantification of risk and how QTRA might address the issue. I am taking as read the 1:1,000,000 and 1:10,000 brackets that HSE has suggested as guidelines. To make it really really clear, this is the guidelines for risk of death. This seems to be ingrained in QTRA calculations. However, does not the common law and the Occupiers Liability legislation create an obligation to avoid foreseeable risk of injury or damage? I don't want a war on the exact wording of the law, I just want to point out that the HSE figures are about death and the law definitions are about 'injury'. To confuse matters, HSE analyses industry accident figures based on 'serious harm'. There could be as much as a degree of magnitude of risk between death and serious harm and another order of magnitude between serous harm and injury. I have worked on large tree surveys where the instruction has been to satisfy the client's Duty of Care responsibility. Had I used the unacceptable/tolerable/broadly acceptable verdicts of the QTRA system or indeed a home-knitted version of it, I could have been far far off the mark and have failed the client. I am not sure I have a question for QTRA, but do you recognise the differentiation I am making and accept that duty of care obligations may not be immediately compatible with QTRA outputs without some sort of adjustment being made to the threshold? Even if it were just to allow for a tree presenting a 1:100,000 risk of death simultaneously presenting a (say) 1:10,000 risk of injury or serious harm? As a tag-on I would suggest that QTRA output for damage to property may be in line with duty of care obligations since the damage is defined by cost of repair. The HSE 2001 document, whilst very thorough, discusses risk without saying risk of what, then jumps straight into guidelines for risk of death. That it seems is a jump that leapfrogs risk of injury or serious harm and leaves no guidance as to what the corresponding thresholds would be for those less serious but higher probability risks.

Av there's no need to apologise, you have brought upon yourself the enormous taks of fielding all manner of questions about QTRA, I have no more right to demand speedy or any answers than you have to demand that we stop asking obvious questions. Your response regarding property is logical. Regarding moving targets, particularly slow moving ones, your position is clearly stated but personally I try to take account of increased target presence time for wider canopies. The difference between a Lombardy Poplar and a Horse Chestnut of the same DBH for example could be considerable. As regards height of fall, again I would tend to differentiate when if the shape of the canopy allows me to. A clear fall of a high-up snow-laden Scots Pine limb (close-grown examples of said species can commonly be 20 m high with canopy restricted to last 5m) onto a road I think deserves higher rating of 'IP' than same size limb lower down. But I take your point about how difficult it could be to generalise for all the ifs buts and maybes. More questions come to mind but you may be pleased to hear that rather than ask I am trying to find the answers from the Guidance Note and this thread, so that I can restrict myself to questions I can't get answered otherwise. The questions I ask are a bit broader than they need to be so as to provide a bit of interest for other readers. Anyway, I can think of better things to do in Singapore than answer questions about QTRA, so your elucidations and our education can continue whenever.

I'm not worthy to be on this thread, but I offer this little stunt fell for inventiveness even if it is a small tree. We had already taken down a tree at the front only a foot away, so I cut a V-notch in the stump of it, and felled the next tree across it and caught the butt in the notch, saving the wall and a fair bit of time.

I just found this, you got to get the variety too. Not connected to the Battersea picture, by the way.

Damn, haven't looked in on this thread for a while, I would have got both the last two. Easy to say that in retrospect though. Here's one for you, I don't know the answer(s). It's in Battersea Park, I took the pic without investigating further as I was in a rush and being ushered by wife mumbling about "tree-bore" again.

I have read both those articles before, very good. Sorry if I sounded patronising, I cna never remember who is who on Arbtalk and how knowledgeable they are, so I just went for an explanation that any reader might follow. You're right, that is less than 70% wood, but I think we both share the sentiment, it is not volume (or cross sectional area) of wood, it is also quality of wood that matters and the soft-rotters take the biomechanics to a new challenging level.

I believe kretzschmaria is the settled name. Adopted by the British Mycological Society with their chosen common name of Brittle Cinder. Ustulina is certainly easier to spell. The other one I need to remind myself has no less than 6 constonants in a row, tzschm looking like the Scrabble hand from hell. I'll bet tehre aren't any other scientific names of fungi or anything that have 6 constonants in a row, unless Mr Kretzschmar or whoever he was was a prolific eponymous namer of things.

Reply to Treeseer's comment. I am no expert on K. deusta, like most people I rely on the decades of knowledge and research by others, so what I say comes partly from my own experience but mainly form authorities such as Schwarze, Lonsdale, Engels, Mattheck etc. I don't know the extent of your understanding of the terminology, so I will assume little. Some fungi decay lignin, some cellulose, some both and some lignin then cellulose. It is the loss of cellulose that results in brittle fracture. What K. deusta does in the right conditions is weaken the cellulose (by hollowing out the cell walls) without much perceivable loss of wood volume or density and I believe some of the strength characteristics of affected wood can remain largely unaltered too. Except of course the crucial matter of tensile strength. Failure is sudden when the loss of tensile strength is overcome by wind loads. This is what I mean, if the extent of wood is being assessed by a hand groping around in a cavity, I don't think that it's quality can be gauged at all, and its quantity only roughly. Attached are a couple of pics from a K. deusta F. sylvatica victim from last year. A bit of an extreme example but the external bark was largely intact and there is well over 70% wood. Adjacent residents told me it snapped and was down in seconds. The ruler in the poicture is 20cm long. The tree was about 20m high.

There's one extra picture of the base of the tree on Flikr that ahows just how close this monster tree is to the house. I am following the speculation about the pros and cons of mulching but ultimately no-one on the forum has seen the size. density and shape of the canopy or the extent of decay and whether it is assymetric. In a worst case scenario the canopy could be heavily leaning towards the house in a northeasterly direction and the decay could be K. deusta related and ready for brittle fracture regardless of extent of wood left. Personally I would advise getting a professional inspection and opinion and reasoned strategy for risk management. It may be something that an insurer could look for retrospectively if the warning signs were obvious.

I reckon you're right with spheroblasts, but they could be wasp galls. Birch seem very prone to Taphrina deformans too and do the strangest things.

Av, is it possible when you have time to outline how the QTRA system factors in or is adapted to deal with a fairly typical situation where the target is exposed to the possibility of a whole tree failing at the base and thus a whole canopy of branches coming down, say 20 metres wide, ranging from 1mm to 600mm diameter? There is arguably a whole spectrum of IPs. And a second question, again if and when you have time, does QTRA differentiate between the IP of a branch of given diameter falling from the bottom of the canopy at 3 metres and from the top at say 20 metres? Thanks in anticipation of your clarification.

As saui before, without actual usage figures or local knowledge the values can't be ascertained but the relative T values you have allocated seem appropriate to me. I would be focusing on the variations arising from individual trees at road junctions, proximity to residential buildings and pedestrian nodes nd any overhead utilities.

It looks like a well used woodland, the Stretview pic of the bend at Vicars walk shows good paths and signage. I don't suppose the actual figures matter in this exercise though. So far it feels like the risk zoning that I already use. I see there is more than an order of magnitude of probability between Target Ranges in the QTRA system, but I am parking my concerns until the lesson is over. We can chat about it at playtime.

Thanks Rhob. It is all very curious. And I suppose one should consider too the possibility that in a full moon there could be night-time leaf transpirational or respirational modes that contribute to the concentration of compounds in the leaf. Or maybe the full moon coincides with night-time insect feeding and the trees have evolved to counteract this by sensing the full moon and producing higher concentrations of insecticides. This is starting to hurt my head. In brief, the moon causes a twice daily high and low tide, high being when the gravitational pull of the moon is at its strongest and when you might expect fluids to be helped up a stem the most. On top of that the sun causes a twice monthly spring and neap tide, spring (not the season but the tide) being when the sun's gravitational influence is highest; these coincide with the full moon and the new moon. So, high spring tide is the biggest on two counts. I have just realised I don't have any point to make.

OK donme the first bit, albeit without actual; traffic counts and knoiwledge of pedestrian usage, but I get the idea so far.

People have probably stopped looking in on this post but I am going to ask a quaestion here about lunar pruning. 'Sap' is sometimes used to mean water (mineral enriched or not) rising to the canopy. It is also used to refer to the sugar rich fluid heading generally downwards from the canopy to the roots. Pruning on the lower stem about this time of year on Acer or Betula usually causes profuse sap bleeding. Now, this could be either the collapse downwards of either kind of sap or the release of upwars moving sap under pressure from below. Or both. So if lunar cycles result in changes in gravitational forces within the mobile fluids in a tree but also changes in the groundwater pressure on tree roots from without the tree, which kind of sap bleeding would high tide or spring tide encourage? Does the question even make sense? I think I mean are there 2 good times a day to prune or 1 good time a month?

Av, thanks for the worked example with the picture of the manual calculator and the software screen shot. It has illustrated the QTRA system as much as (and in conjunction with) everything else you have said.

Hey JonnyVine, don't worry about offending me, I had just come in from the pub and thought I was being funny in my innuendoland reply. I really ought to use those emoticons so you knoew I was saying "thrust" in a Benny Hill tone of voice.

And then sold it to Tescos as barbeque charcoal...

Oh dear, I see we are in innuendoland! I had thought the general thrust of my argument would have over-ridden everyone's individual urge to fixate on the nuts and bolts.

To Acer ventura Comments noted, I wasn't having a bad day just a busy couple of ones in a row. As you are the sort opf person who clearly tries to use languiage precisely, a term such as 'nuts and bolts' was always going to be wooly. I suppose what I meant and which you have more or less confirmed is that the PN really just says that there are nuts and bolts but doesn't let us see them. I suspect the people opn the Forum will reserve their position on QTRA until tehy have the nuts and bolts in their hands to poke and pull at and satisfy themselves that they are solid. You are now getting asked a lot of questions and I am not for now going to trouble you with any more. I would just reiterate that the example in Kelvinside is effectively confidential but that I am quite happy to describe exactly the Black Pine situation (without stating what I then advised and why) and if you are willing to illustrate what advice your approach would have resulted in I will simultaneously do the same. The spoecific case doesn't matter, it is more for onlookers and me to understand how your system works in practice and what a more rudimentary system does by comparison. I do not want conflict, only advancement of understanding. It can go in a new thread if need be, this one is bifurcating like an Elm branch.

That was easy.

I'd go with K. deusta too. Whatever it is it is really quirte a beautiful pattern, I'd cut a thin slice and polish it and put glass on top and have it as a coffee table. Unless it's really smelly (he says, fishing for further clues)!?

Quick response to Jose's post. If Council refuses an application and the damage then caused by a tree was foreseeable, the Council is statutorily responsible for compensation. Have a look at the Act, I can't remember the English Act paragraph.