James

Good morning Treeseer, I think we are mostly in agreement... You end your CEU article by saying, 'After reviewing the options, the owners decide which corrective actions to take and prioritize when to take those actions. If other abatement or mitigation does not meet the owners’ needs, then they may decide that removal and replacement is the best answer for some trees. The ultimate goals of tree risk assessment include maintaining a secure environment, maximizing the benefits delivered by the landscape, keeping maintenance affordable, and demonstrating the value of arboriculture.' I can't fault that. It seem that so far, to only area of disagreement is the term 'obvious defect'. And even then, I get the impression you only don't like it because of how it is used, rather than what it actually means. Hang on though... I've just noticed it hidden away in there... a recommendation to use QTRA I'm not gonna discuss that system on here (unless someone is happy to show us an example report we can discuss). Every report I've ever seen using that system has a strong whiff of pseudoscience. But it is impossible to have a sensible rational discussion without an example report to go on. But I really had to pull you up on this one... 'Removing the dead branches reduces that risk to 1 in 45,000, far safer than the 1 in 10,000 that is considered by medical groups to be an acceptable level of risk to the public.' This is incorrect and shows a very serious misunderstanding of the Tolerance of Risk Framework. I can explain this more later if you like - but I've got to dash to a meeting now.

Tony, rise above it, don't let them get to you. I'm not looking for justification, and I'm certainly not having a pop... I honestly wanted to know your reason for starting this thread. You brought up so many issues in your first post that I'm genuinely confused. I just wanted a bit of clarification, that's all.

Thanks Treeseer, it's easy to feel slighted when it's not intended on forums, so I appreciate the reply. And next time I'll give you a page number so you don't have to trawl through pages of stuff to find the section in question I'd be interested to hear your thoughts on why you think the term 'obvious defects' is useless and misleading though. I use the phrase quite a lot, it's useful and I don't find it misleading at all. If it's time for a re-think I'd be very glad to know.

Although, I think you should listen to pedroski - he is a doctor after all

It's probably common hogweed in our part of the world Dean, although I've seen some giant stuff next to the M62 recently. I've had a few blisters off the common hogweed, but no permanent damage - all was ok after a couple of weeks.

Ahhh! I see... I shall keep quiet for now then

David, I think it's '...carry water and nutrients to the mycelium under the bark being attacked. These rhizomorphs extend back to previously rotted roots and stumps, leaves or even the soil. Control: Existing Techniques In landscape situations, all sources of infection such as infected stumps and...' Interesting article that, thanks for posting it Treeseer.

Wow, I'm not entirely sure, but I think I've just been accused of making quick and erroneous 'condemnations' of trees. The definition I gave for an 'obvious defect' was just off the top of my head, but it'll do for now. I suspect that most people would know what I'm getting at. But if you do want a more detailed definition try this document: http://www.forestry.gov.uk/PDF/FCMS024.pdf/$FILE/FCMS024.pdf I also suspect that most people would recognise that an obvious defect does not necessarily mean that a tree has to be 'condemned' (not that I'm entirely sure what you mean by that word). Again, this is old ground, covered in the above document. I still don't know what Tony is getting at though... Please Tony (aka Hama), you started this thread, and although there's several people who appear to understand what you're getting at, I'm afraid I don't. I know from past discussions with you that you are incredibly passionate about trees, but I just don't know what you are getting at here. Give us a shove in the right direction please

Paul, out of all the stuff that was said to you, the one that would really pee me off is the comment that your work is a scam... that would probably even drive me to a bit of cussing

Mabbs, that's an interesting paper. But I couldn't seem to find any mention of a control plot...

Treeseer, you've opened up up a whole load of questions there... I'd suggest that before an arb can 'look for ways to mitigate/lessen that risk to a tolerable level' they need to first know both what the level of risk is, and what the tolerable level is. I'm reluctant to get into that just now (cos it tends to cause arguments), I just want to know what Tony is getting at, I have a suspicion I agree with him, but I'm not sure - cos I'm not sure what he's getting at Oh, and obvious defects? Well, I guess what I meant was arboricultural features which would be recognised by many arbs as being a potential indicator that the tree/s in question may have an elevated level of risk of failure... or something along those lines

Tony, I think I'm starting to see what you are getting at, but I'm still a bit lost.... Are you saying that trees with obvious defects should be retained - even when they are located in areas where they might pose a threat to people and/or property? I've got a very genuine interest in this - I did my MSc dissertation on a similar subject :-)

I'm seriously tempted. It's really good to see the AA doing stuff at an affordable price AND in the north (I'm thinking of both Arbfest and the TPO/BS5837 Roadshow here)

Hey, there's nothing wrong with being a bit bonkers I'm afraid I am missing the point though - what are you trying to get at? I'm not having a dig or owt - I just get the impression you're trying to say summat, and I'm missing it

That looks like fun - I've registered an interest, thanks Paul, I'd probably have missed that one if you'd not put it on here

Andy, I wish this site had a 'like' button similar to Facebook. I would have 'liked' your post. :-)

Hi Jesse, I'm sure you are taking all the necessary precautions, but for the sake of anyone else reading this who may be thinking of including soil assessments in their BS5837:2005 surveys I'll say this: Please be extremely careful! Soil structure and its suitability for new foundations is considerably more complex than a simple PI test. In my 8 year experience of professional consultancy, it is the architect's job to assess soils and their suitability for whatever is being built upon them. This is what they are trained, qualified and insured to do. And if it falls outside their remit, then they usually obtain soil engineer reports. I have heard stories of architects facing serious legal action for failing to make the proper considerations in this regards.

It's a nice site that one - you got any pictures of the tree Dean? I'm just curious how it turned out.

"Maybe you can't find the research because it ain't there?" Unfortunately I think you're right - there doesn't seem to be a coherant body of research into this. Still, there are some tantalising bits and pieces. Thanks to all who replied, I got some good papers to add to the library.

Completed one for you.

Tony, you are of course correct. The precautionary approach is used when there is a lack of knowledge or where there is high uncertainty or risk. So, without proper research we are forced to use the precautionary approach in all sorts of areas of arb. I think this is sometimes unfortunately seen as guessing by non arbs. That's why I'm so keen on finding proper research - it cuts down on the guessing. Does seem a bit odd though that the few existing research based papers (as opposed to opinions and literature reviews) seem to suggest trees can take considerably more direct damage and disturbance than the the current british standards allow for. I wonder why that is?

Bundle 2, Thanks, these are great. The paper on planting depths was not really what I was looking for, but the Hamilton and the Perry papers are very interesting. Did you notice that Perry and Hamilton seem to diagree on the significance of root damage?

Hamadryad, I agree about the decay issue, but do you know of any research to back this up? After all, there are many arbs who believe that root decay does not necessarily lead to failure.

Arborist Sites, it sounds like you might have some interesting case studies. Any chance of talking to you about them? It would be useful to know someone who I could pass this sort of work onto.

Thanks for the replies everyone, interesting stuff. I've already read most of the suggested literature, but the one posted by Bundle 2 was new to me - thanks. From what I can gather there seem to be no body of research into the effects of root damage on established trees. But there is a wealth of literature telling us what we can and can't do near trees based on guess work and the personal experience of the author. Most of my work is with trees on development sites, and I'd be really interested in knowing more about both the effectiveness of remediation work available and people's experiences of what happens to trees when the roots are damaged. My personal experience is that in some situations trees can take a lot more direct damage than the literature suggests.