Amelanchier

I knew that was a metaphor too far Tim... Maybe that's a topic for another thread???

Sorry, didn't mean to give the impression that it was my idea! This 1981 paper was the synthesis that kicked off the idea. Its accepted fact now. Evolution by Individuals, Plant-Herbivore Interactions and Mosiacs of Genetic Variability_Whitham &

So an Oak lives for hundreds of years. Defoliating insects might have two generations a year. You'd think that the insects have the upper hand, they're mobile, breed fast, and can adapt over generations to any defences the tree might have. So how come the tree gets to live out its days??? It evolves. Trees can't run away from trouble or look for better environments. They change or die (or struggle for years then die). Trees (as you're probably aware) are generating systems. They don't heal wounds, they seal them with new tissue. The damage is always there just compartmentalised. Trees are also modular. Stems, limbs, branches, twigs, leaves and buds are in competition with each other - the perfect capitalist market economy. Those parts that are profitable last another day. Those parts that can't pull their weight get surbordinated or binned. Ok - I've been rambling, but there is a point. Every part of a tree, grows from meristematic tissues. Those tissues can mutate during normal cellular division. This means that a bud can be genetically different to the others. This means that whatever that bud turns into will be genetically different as well. So bud becomes leaf, flower, twig. All the parts that arise from that new growth will be genetically distinct also. This means that mature trees can be made up of a 'mosaic' of genes. This allows natural selection to act on parts of the tree. Reversion is a good example, reverted leaves are more productive and will outcompete the variegated, purple, cut-leafed types. Buds mutate back to their wild type and just do their thing. To go back to where I started - leaves under attack from defoliating insects produce chemicals to defend themself. Leaves that are better at doing it don't get eaten. A genetic mosiac of foliage keeps the tree one step ahead. Also adventitous buds lie dormant until released by changes in hormones or sunlight. These can also be mutate but won't be expressed until needed. Evolution in a bottle!! Stored for a rainy day.

Whats more impressive is the process by how they do it though!!! Evolution by modular somatic mutations! I'm putting a thread together about some stuff I've been reading. Will get round to it soon

Acer platanoides 'Drummondii' is the classic. Prunus cerasifera 'Nigra' often does it as well.

Well, you've competed the first part of the VTA process. You suspect a defect (decay) because of symptoms (fruiting bodies). So, onto the second and third parts:- 2. If a defect is suspected on the basis of symptoms, its presence or absence must be confirmed by a thorough examination. 3. If the defect is confirmed and appears to be a cause for concern, it must be measured and the strength of the remaining part of the tree evaluated. I'd suggest some means of decay detection equipment. Resistograph? PICUS? Even a increment borer if you're feeling sadistic. That way you can complete parts two and three at the same time. Remember its not the extent of the decay thats important, its how strong the remaining parts of the tree are. The findings will determine if any works are necessary.

The authority on such matters is "The Law of Trees, Forests and Hedgerows" by Charles Mynors. Pricey book though, last time I looked it was over £100. Parts of it are available on Google Books. However, in general terms with regard to neighbour disputes. Just tell them to get a solicitor to sort it out not a tree worker.

No we definately don't want to travel that road!! Numpties would be mitigated by the reast of the spec I would hope... "Crown reduce by the removal of the outermost 4m of the leaf bearing canopy back to suitable secondary growth points. Ensuring a flowing branch line and a natural crown habit for the species. Resulting pruning cuts will not exceed 100mm in diameter." When the draft BS3998:2008 becomes published then requiring works to be done to that standard will certainly add weight and detail to any spec!!

I appreciate your position Ben. The scale of reduction is an issue. Perhaps it might be better phrased as "... no more than 2m"? I'd anticipate that the majority of removed branches would be smaller than that. Like wise, the cut diameter is the maximum, not the norm.

I think we have a little confusion on what sort of trees I might be specifying an all over 2m reduction on! Very species specific!!! All of the techniques you've described are exactly what I would do and recommend to others. Don't take the 2m bit out of context. I'm not specifying a lop! My point is, if you are professionally writing specifications for others, you can't be sure if they know what you know. You have to assume they know next to nothing. If you spec 20%, you have no control and as a professional you've just wasted your time and effort. While you might complain about the tape measure - how else could you enforce works?? How can you check to see if a TPO tree has been reduced by 20%???

Sorry. I think you can guess that I clearly didn't read the post properly

Andy I'm going to steal that fourth one of the Ash. It'll be useful to illustrate this theory I'm reading up on at the moment. I won't bore you with it here, I'll put it in a thread (then I'll bore you!)

Everything in moderation.

Bloody good question! I'm well aware of our differing opinions on personal liberties though and this thread is an attempt to discuss the guidance document (although no-one has actually read it!!!!!)

They tell you how to do it because our taxes pay for the NHS costs and disabilty benefits you might need if you do it wrong. Its a inevitable outcome of the welfare state. It's not personal, its economics!

You need to be careful what you tie into though. Those alu cages won't take much of a force in certain places/angles. Also when bailing out of a platform, take extra special care of sharp edges on the basket. Oh and boom grease is a sod to get out of your rope!

You might consider scaffolding (or your original phrase - "fixed raised platform") for hedges...

Ha, who needs fireworks! Great shots guys! The Norway Maples round here look like they're on fire! Never seen such colours on such a boring tree. Anyone else got blazing Norways???

Well after those pics I'm formally changing my mind back to G. resinacium!!

Have you attacked it with a lighter??? Any chance of a phot of a cross section showing the tubes?? I'm sure it's a Ganoderma spp. but looks like it might have a laquered upper surface??? Could even be G. pfeifferi???

I can't put it any clearer than Buzz did... I don't think I've ever done a reduction that was different in any way to the ideas proposed in RvT... I find it hard to imagine a reduction that wouldn't involve some thinning. No-ones going up the tree or standing next to the chipper with a tape measure, they're approximate by the nature of trees but its a context thing. If I'm writing a spec for someone else to follow (which I do quite a lot), I don't want them to have too many options. I don't want fluff and fudge, I want exactly (or near enough) what I recommend.

Anyone seen/bought/read the new AA Guide to the Use of MEWPs in Arboriculture?? http://www.trees.org.uk/publications.php If so, are there any points of interest??

Why would you want to use a screwgate at all? i just don't see the attraction :shrug:

The email I was sent estimates that the cost would be £470 for Arboricultural Association members and £505 for non-members... I can recommend the course.

Anyone interested in taking the AA/Lantra Professional Tree Inspection Course in Norwich should send me a PM. We're looking for numbers before booking the instructor.