Amelanchier

Clearly Mr Lonsdale is entitled to his opinions (well that is to say, they are certainly his to have). I don't know that I would agree that every tree different in respect to hazard assessment. There are certainly a great number of trees that are much the same (i.e., plantations / shelter belts) and even more trees that are just too young, small or remote to be a hazard. Of those that remain gravity ensures that there are only so many ways that a tree can fail and those failure modes affect a predictable area around the tree. Very few explode; even fewer implode. It is within that small set of possibilities that we are expected to differentiate probability with a liberal smattering of precaution and I am personally of the opinion that it is reasonable to set out a system for doing so. Quite often, I use QTRA for doing so - especially when there are a lot of trees to compare and prioritise for a client.

Look at it in context. What are the options for assessing a tree? You can go to it, poke around a bit, find a problem, follow VTA and if neccessary come up with a spec that will reduce the risk associated with the problem. Great but is that tree worth doing more than its neighbour? Is it worth doing at all? What do you compare it with? How can you show that you assessed both it and its neighbour on as equal a footing as possible? How can you show that the work you specified reduces the risk? How do you ensure there is a paper trail of your decisions?

I would argue that given our individual experiences and physiology, we are not capable, even for a minute, of an objective view. We can certainly strive for it and some of us are even obliged to (the judiciary more so than arb consultants!), but we can never truly achieve it. Therefore we can only ever make a subjective interpretation of a quantative measure! We colour the data with our bias and history. Also statistics can be qualitative. How would you rate the clarity of this reponse on a scale of 1-10, with 1 being the lowest and 10 being the highest...

Sorry that was a bit abrupt - your post is worth a longer response! Statistics is not a dark art, it's a method of evaluating and presenting data. Sure it can be manipulated but what can't be? Subjectivity is... well... subjective!?!? The application of stats in QTRA is to define a suitable threshold for action - 1/10,000 is presented because that is typically what is used in other areas of risk decision making. The calculation of the final QTRA value (the Risk of Harm or RoH) depends on a fundamentally subjective assessment of the tree - the likelihood that a certain part is going to fail and the remainder just quantifies the impact of that risk in a rigourous and systematic way. Having a threshold to benchmark those hazards against that can be justified places you in a stronger position than if you made one up yourself... As for that Australian ruling - its odd how much that crops up. I was once reminded of it in the feedback sheet from a tutor in relation to some coursework that dealt with UK tree management as if it somehow rendered the whole QTRA enterprise redundant. AFAIK UK courts aren't obliged to heed passing comments from their peers down under anymore than they abide by ours.

As far as I can see QTRA doesn't pretend to be anything but subjective.

I give that one a fortnight.

Not to mention the fact that if you want to see the full references - you need to pay £3.50. Not very transparent - and almost guarantees a self selected and supportive audience...

Before GM (which AFAIK can include interspecial transfer i.e., from one species of tomatoe to another as well as the interfamilial transfer described by HCR) the top industry technique was irradiation. Plants would be bombarded with radiation to induce mutations which could then be selectively bred into target crops. There was no way to even guess at the negative consequences as the mutations were random - some would be expressed in the phenotype and some wouldn't, but they'd still be there. The anti-GM lobby happily grew up eating this food and lived to complain about the improvements to risk management that GM offers over the old system.

Yes. Fortunately in my experience, the pre-emptive feller is a rare beast. Where they exist, their desire to avoid a material consideration / site constraint faces off against the duty delegated to tree officers (a legal duty no less) creating a Hobbesian trap where each strives not to be caught out and is increasingly tempted to a first strike. An arms race. When clients ask me about pre-emptive felling I certainly begin with whether it's legal or not in the given circumstance but remind them that legality is only part of the equation. Once you've felled the tree/s, they're gone and you are not necessarily guaranteed to get your permission - so if you're developing your garden you need to have a think about whether you would be happy without the trees and without the development in the worst case scenario. Also if we're talking about publically prominent trees, TPO's notwithstanding, have they considered local sentiment? I know of a site where a row of large lime disappeared prior to an application (on a bank holiday). Plans came in and then so did the objections from neighbours and local residents - over a hundred of them. These weren't throwaway nimby objections either they were precise, detailed and valid. App was withdrawn before it went to committee and the site was sold. Presumably at a loss. Finally, and putting aside allegations of unfair attachment to unworthy trees (though I have been there), the TO / planners might simply ask for more landscaping. They are obliged to consider the site as it is and not as it was but a gap is a gap and if it can be planted it probably should be. That might not put anyone off, but it should be costed into the decision.

Of course he could fell the trees and still be refused permission...

Google not working? One is a set of distinct concepts in a scientific discipline and the other is a premise so evident as to be accepted as true without controversy. One can build a paradigm of axioms but not an axiom of paradigms.

Sigh. So many cruel retorts at my fingertips, so little time. Even less motivation.

I care about clarity and precision. When I say things I like people to know exactly what I mean - that way both they and I are better able to tell if I'm talking rubbish. It keeps me on my toes. I could use vague half truths, empty generalisations and woeful sentence construction to get my point across but I think that's counterproductive. Where's this tools based forum? Rebranding the site to ease your existential angst about feeling rejected by 'the man' doesn't change reality. The members will use it as they see fit, those that don't like it can leave - as many times as they like.

I capitalised one to make it distinct from the other when they were side by side.

That squabbling is critical to the scientific process. If it is to be any use at all, a theory must be able to withstand a good kicking. The Axiom (note capital), notwithstanding the lack of challenges to its veracity, has no evidential basis. That is why Mattheck defined it as an axiom (note lack of capital) - a premise so evident as to be accepted as true without controversy. It might be argued that by questioning its truth, you negate the conditions needed for the Axiom to be an axiom... In any case, any challenges to it will either strengthen its claim or sweep it away - either result is progress.

Clearly you'd need to pick your battles - it would be a poor idea to increase wound surface area on a stressed tree - but have you seen the Watson paper attached? Very good compartmentalisation, even in Liriodendron! Time for another experiment? Watson G 2008 Discoloration and decay in severed tree roots Arboriculture & Urban Forestry 34(4).pdf

Good man. Toothed or untoothed bucket? Roberts et al 2006, Tree roots in the built environment. HMSO - derives figure 10.14 (below) from Watson, G.W. 1996. Tree Root System Enhancement with Paclobutrazol. J. Arboriculture 22:211-217. I found that digger torn roots of Willow produced a better growth response (more and longer new roots) than airspaded clean cut roots under the same conditions for my dissertation. Of course Willow roots readily but you've got to start somewhere

That has always struck me as odd. Why treat roots as if they're branches? The available literature seems to suggest that a healthy optimal response to root severance is the production of a profusion of new roots from cambial callus tissue and the tissue immediately adjacent to the damage. These new roots compete for resources that have been made available since the severance; underging primary and secondary growth until only a few large roots remain blah blah blah. Essentially subterranean epicormic growth. But aren't nice tidy natural target pruning cuts intended to minimise epicormic shoot production? Small, clean cuts minimise the proportion of damaged cambium and limit the differentiation of adventitious buds - why would we want to do that to roots? Why limit or control their natural response. There's no aesthetic to consider and roots compartmentalise better that any other part of the tree - besides doesn't the tree need to re-assert its water / mineral uptake as fast as possible to avoid cavitation / dysfuntion? So what do we do above ground when we want to stimulate epicormic from a branch? Fracture prune. Make some ragged torn ends; put away the airspade and get the digger in.

I've been asked to ask the collective consciousness of the 'talk how much the following PAYE employees get paid - the idea being that I can calculate an average to quickly see if pay is in the right ball park. A climber with approx. 5 years experience aged 20 -30. Bunch of tickets / trailer licence / supplied PPE / not too much overtime blah blah Mr average but decent. The above but in charge of a team of three. Clearly there are lots of variables so this isn't going to be particularly accurate but I can live with that. If you could give me average annual salaries for both and whatever assumptions you've made in doing so it'd be much appreciated.

Breach of condition notice and/or enforcement notice. BOC notice may prevent the client obtaining a certificate of lawful development for the site unitl the breach is dealt with (leading to problems selling the land on). EN normally requires that the deviation from the agreed scheme be rectified - in this case the best that can be reasonably hoped for is a fairly large replacement tree. Failure to comply can lead to prosecution.

Perhaps, but then I didn't say it was futile; just vapid and mundane. Perhaps your pinnacle is reserved for the futile observation of the observation of futility...

Sigh. And thus the familiar pattern of arbtalk reappears. An allegation is made, knees jerk loudly and epic reactionary pronouncements are made. In the hinterland of these brazen statements, a spinoff debate occurs of transitory relevance to the original post before dissipating impotently into further allegations. Meanwhile new posters will react in vain to the transparent implusivity of the knee jerking, perhaps with the fair intention of bringing some balance, and a new parallel confrontation occurs as positions harden despite their often unstable footings. After much grief and retrograde vitriol, the thread sinks beneath the murky depths of the servers. And no-one will have learnt a damn thing. All the better to begin again another day.

Privet Hawk-moth (Sphinx ligustri); awesome creatures.

For those of you who have access to the new improved AA Arb Journal - this letter and Duncan's response to it are featured in this months edition. Personally, I find the weight of evidence for the Slater Harbinson model entirely persuasive.