daltontrees

I think what troubles you is what troubles everyone. Putting a £ value on amenity. But as soon as a TPO'd tree is removed without consent and a measure of the penalty is required, people will try. Which reminds me, did you see the recent appeal court case in Poole, Regina v Davey? It could be a useful one for people to look at here?

Out of curiosity do you work for, or have you worked for, a Local Authority? I think you have listed the right questions but I think they can all be rephrased as follows - How much would it be missed if it went, and by whom. And for how long? How much does it add to the neighbourhood? How badly does it need replacing, and how urgently? By a replacement of the same size and species? How worthy is it of a TPO? And what difference does that make to the value? And you didn't mention the poor owner... And now my head is starting to hurt.

There should be! But Helliwell doesn't try. CAVAT sort of tries insofar as it multiplies the tree value bya rounded-off factor that reflects the population density of the local authority area. Which is a decent stab at the problem but doesn't work for anything other than LA accounting. And the resultant number is as consequence arbitrary. It is incapable of being tested against market values or costs and therefore is not really a valuation. It is, however, a measure of worth (see earlier comment to Mr Clark) if the LA accepts it to be one.

That is my main thrust, not because of the rather distateful bean-counting tendency in modern life to reduce everything to a financial decision but because I don't see any other way of weighing up costs, private amenity values, public amenity values, risk management decisions etc. They must surely all be measured in the same units and the same currency, and all be capable of being related back to testable market values or market costs?

I agree that CAVAT is useful for LAs. I don't think it has any other use. CTLA I believe is the future, it is the only system that is a true valuation rather than a monetised amenity assessment. iTree seems to be a monetising system too. So which tool is the right one for the job here on my hypothetical tree? What if Helliwell produces £2,500 and CTLA produces £1,000? It could be life or death for the tree.

One might also consider the gambling involved in retaining the tree. If there is a 1:20,000 risk of it killing someone and triggering a £1M law suit, the cost of that risk is perhaps 1/20,000 of £1M which equals £50 a year. That is what I see the QTRA approach as doing or allowing you to do.

My hypothetical tree has Meripilus, let's say it is not practical to try and ameliorate its environment and that investigation shows that the underside of roots and butresses are in a fairly advanced and untreatable stage of decay. I am guessing form what you say that you would expect the cost of treatment to be uneconomic, exceeding the value of the tree. Valuers make a very specific and important distinction between 'value' and 'worth'. For that reason as an ex property valuer I get really cheesed off with the 'how much is a tree worth?' debate. It is worth £x to the owner. It is worth £y to the neighbour. It adds £z to the bids that the house would get on the open market, which is what it is worth to the highest bidder in addition to a hypothetical treeless house. And it is worth £w to the public, which if this is high enough will probably get it TPO'd. It's worth nothing to the arborist except as a source of profit for felling or pruning it. These are all measures of worth. Not of value. The value is ....?

To those onlookers who haven't used valuation systems, the hypothetical position I think can illustrate an important principle that should always be present in valuations, and that is that the length of time that the benefits of a property can be enjoyed affects its value. What the Helliwell system does amongst other things is multiplies the value of a healthy tree by a fraction that reflects its short future. Thus a tree with long likely lifespan might have a value of £10,000 but one that is the same size you could only expect to have a less than unacceptable risk of 2 to 5 years has a Helliwell value of £10,000 x 1/4. CAVAT does the same thing only, in my opinion, considerably better. iTree doesn't even try. I agree with the principle more wholeheartedly than I do with any other aspect of tree valuation methodologies. iTree fails. CAVAT gets full marks and Helliwell gets half marks for trying.

Here's a simple example of the issues. A midsize tree growing in a front garden, much loved by the owner, is found to have a fungal infection that will cause it to fall over within 10 years. Without this infection, the Helliwell system values it at £10,000 but due to the infection its value is reduced to £2,500. It will cost £1,000 to remove and grind out and a young replacement will cost £500 to plant, stake, mulch and maintain for 2 years. The risk associated with failure is currrently 'tolerable' (1:20,000) because although failure is likely the chance of it hitting anyone or anything is relatively low. However, the insurers will not cover the owners if someone or something is hit. Crown reduction is suggested, but although this will reduce windsail and will temporarily make the tree safer this will reduce the tree's chances of resisting the fungal infection and will cost £250. What does the owner do and why?

As suggested recently elsewhere on Arbtalk by kevnjohnsonmbe, there seems to be interest in a debate about what amenity value really means. So this thread is open for any contributions to the debate. Or anything that anyone wants to put in here like links so that it can serve as a mini resource. The subject has barely been touched upon ever in Arbtalk yet personally I see it lurking in the background of many discussions unable to come forward and speak because it doesn't have the right words to use. I will open it with a few suggestions. First of all, I don't mean wood value or valuation of forestry stock (although there are grey areas in this regard, perhaps that's why 'amenity tree' needs to be defined or we need to talk about the 'amenity' provided by trees whether they are forestry or arboricultural trees). Secondly, opinions will differ about amenity and how it is affected by good or bad management, and unless the debate can gravitate towards objective (or minimally subjective) measures that take the observer's personal views out of the value, then it will all be a big fat waste of time. Thirdly, and in the same vein, I am most interested in a numeric outcome (say ££s) that can be weighed up against tree work costs and property values. Finally, starting off with the intention of keeping it simple seems highly desireable, the simpler it is the more people will use it, but I have spent a lot of time thinking about it and I know it is not simple and never can be. It's like saying accountancy is simple or tree surgery is simple. If contributors all approach the debate not to pick obvious holes in ideas but to try and fix holes by simplifying wherever possible, some consensus might emerge.

I knew I couldn't stop myself. I am going to start another thread about this just now. I don't mean to steal your thunder, but I am laid up with the cold today and have time on my hands to do it. I will put it in the 'General Chat' section and call it something like 'Valuation of Amenity Trees'. See you there, folks?

Sorry, here's a closer shot of the Ff in the last pic. Anyway, these two species don't seem too fussy about co-infection. Pb is a brown rot of the stem, resulting eventually in brittle failure. Ff is a white rot of the stem, often resulting in a still-attached partially brittle partially ductile fracture. Like Jack Sprat and his wife, they appear between them to lick the platter clean. I was unable in a short period to reach any reliable conclusion as to which species came first, whether one operated gnerally higher from the ground than the other or whether there was any conflict in modes of decay between co-infested or secondarily infested stems.

The following pics are not that remarkable, as Fomes fomentarius and Piptoporus betulinus are both very common on birch. I was up near Grantown on Spey and Aviemore at the weekend, first I spotted a couple of nice examples of each species (first and second pics), then two similar Birch stems beside each other, one with Ff and the other with Pb. Finally (last pic, look closely top and bottom) found a stem with both species.

Definitely one for a separate thread. The current preferred mechanism for assessing amenity value in Britain is deeply flawed. Ask a question about tree amenity value in a new thread and I for one will probably be unable to stop myself contributing frankly.

Why was it cut down? I too am curious about the soil. If it is permeable granular stuff then some trees could tolerate that because they can still 'breathe' at the roots.

I take Cod Liver Oil every morning, I can't say whether it works or not because I'd have to stop taking them for a while to see if they are making any difference. But I know that they are a good thing generally. The only other thing I do to see off joint troubles is when I am working really intensively for weeks on end I sleep wearing woolen gloves. A bit weird but my hands and wrists stay hot all night and seem to heal themselves. Worth a try for a few nights, if nothing else it's less creaky to get out of bed in the morning.

If it's a milk cap you won't have to try too hard to get milk from it. One of the things I always find useful to narrow down the identification of fungi, at least the ones with gills, is the gill attachment. Some gills are only attached to the cap and not to the stem (k.a. 'free'). Some run right down the stem (k.a. 'decurrent'). And there is just about every permutation in between. The main thing that made me think these were Paxillus involucra was the definite decurrent gills, although I had to stare at the original photos for a while to convince myself that they were decurrent. With your updated pictures it is much clearer. And with the rim definitely rolling now.

Or could be Paxillus involutus?

Looking alittle further, I see that Stihl's policy is more like 'does not allow delivery of Stihl products bought online or over the phone, unless the dealer conducts (or has previously conducted) a Stihl professional hand-over with the customer or the customer is a known professional. A known professionalí would be someone who has recognised qualifications in the appropriate field for the machinery they are purchasing and/or has dealt with the dealer before.' My supplier is legitimately supplying me, then. If anyone's longstanding Stihl dealer has just recently insisted you come in to collect every time, they may be applying the policy too strictly. If they choose to lose business that way, that's up to them.

I know, but someone else did it on another posting thread recently too, the supplier wouldn't have done it if I hadn't demonstrated my competence with chainsaws by ordering dozens of spares off them int the past.

Quite bizarre spread, tree looks like agiant leafy catapult, client confidentiality prevents me from saying much more than that.

No it's just in woody mulch. I found loads yesterday at the base of a Liriodendron tulipifera, a compression fork at the base had torn off a few years ago, leaving no chance of recovery in that sector. I reckon the root on that side must increasingly be in a bad way.

I think a 2 thread is best for general purpose. A 3 is faster in soft wood, that's the only reason really to use it.

Update: my usual stockist just took the order over the phone, bless them, because I am an existing customer. Took 2 minutes. Parts will be here tomorrow. It's just Stihl that's the bams then, not the sensible stockist.

CURSES to Stihl. Today I wanted to get a filter cover for a 230. That one that you just turn the wee black knob at the back, lift it off, put a new one on and turn the knob again. I could do it behind my back in th dark, in a tree, in a gale. But I have to trudge off somewhere and pick it up so that Mr Stihl's minions can explain to me how to do it safely? And pay twice as much plus the earning time spent getting there and back and listening to instruction that I don't need. CURSES to them and their ludicrous policy. Next time it's a Husky. Or maybe a Makita.