daltontrees

I like the idea of a picus co-op, but I can't think of many people that I would trust to use it. A good way to do this would be to get a group together, one person buys the kit, they all get together for a day's joint playing with it, then the owner rents it out to trusted trained group members and that way he can record condition and function before he sends it out and paperwork can make borrower responsible for return in same condition or for cost of repairs. I'd sign up for such a scheme, but I wouldn't want to take the initial capital outlay hit on it in case no-one else borrowed it off me. Like you, if I had one or I was the main guy in a co-op I'd really be pushing it as a service. The perception that it's a very expensive service is correct in reality, but if using it all the time you might get slck enough to half the price of the service. On a supply/demand basis this might improve uptake and turnover.

Great opportunity Island Lescure. You were the guy on the ground so it's hard to comment on the judgements you had to make. You were still finding roots as thick as a wrist out at 15 and 17m, that must be some tree. And the spread is c.17m. I see you capped the RPAr at 15m for a DBH of 1600mm. Maybe in areas of different climate where rain is less consistent a bigger RPA might be particularly important. My gut feeling is that the area around the tree on the very edge of the crown is partularly important for water. It's called the drip line for a reason. For biger trees, like yours here, the 15m RPAr cap seems to deny the tree this collection area. Maybe the full 1600 x 12 = 19.2m would have been beneficial if building pressure hadn't been there, giving a 2m ring around the crown fro water collection? And speculatively it might be beneficial to reduce the spread artificially by pruning (I see you have anticipated pruning anyway for future buildings near the tree) so that the drip line water contribution is brought closer to the stem. Anway, a good read it was, thanks for sharing it.

Do you have an alternative more relaistic formula based in science? I have never seen justification for 12x, but it usually works, which is justification of a kind, as the trees tend to carry on. It may be too big, but I don't thnk it's too small. Based on the empirical evidence I would disagree that it's 'hugely unrealistic'. I would say 'simplistic' and I'd drop the 'hugely'. I too am happy to be corrected. And what we are dicussing here I think should be thought of as potential crown volume correlating with rooting volume, and whether these are reliably linked by stem diameter. Physiologically ongoing vitality for pollards should reflect potential crown volume, not artificially reduced crown volume, relating that to rooting volume. I still see no rationale for reducing RPA below 12x for pollards. Whether 12x is the right number for all trees is another matter.

I really meant an isolated topping will encourage new wood with increments as big as previous years. But yes I expect regular cyclical pollarding would stunt stem development. And even with small increments, they might not get smaller after re-pollarding. And the question remains, would the stunted stem DBH give an adequate RPA per 5837. I expect so.

Or, don't pollard a veteran that is about to have its rooting area compromised by development?

My post went in a thte same time as Benedmonds. Not trying to stat an argument here, just questioning Paul's 'sound logic' suggestion.

I'm going to give an alternative perspective (otherwise known as disagreeing). Naturally trees have a balance between the below ground and above ground parts, commonly called the root-stoot ratio. The absolute value of the ratio doesn't matter, and I am sure it changes gradually over the lifespan of the tree. The top of the tree puts gases and energy in, the bottom puts water and nutrients in, and the two parts mature together. Cut some roots away, and the tree will immediately try and replace them. Likewise pollarding, remove crown and the tree will bounce back vigorously. The only constant measure of the balance that would be achieved naturally is the stem diameter. And by simplistic methods, this is used to determine the root protection area. The stem is the main plumbing for the tree, up and down. BS5837 assumes its cross sectonal area is proportional to the root protection area. Pollarding doesn't reduce the rooting area, it just forces a new crown to start growing. Reducing the rooting area at the same time as pollarding may reduce the overall growth rate of the tree, but it won't cause the stem to shrink. It will just make the tree unwell and unable to regenerate a crown. So you won't have a pollard, you'll have an ailing stick. A full BS5837 12x RPA is in my view needed to make pollarded trees viable, to constantly try and regain the root-shoot ratio. Push it too far by removing RPA and you are well into the area of not knowing of controlling what willl happen. The stem needs a certain amount of energy in to maintain its older wood as well as create new wood. BS5837 defines RPA in terms of maintaining viability. It doesn't say keeping alive. That's my view anyway. I have never reduced the RPA of a pollard. All of the above is not book learning, it comes (for me) from never ever missing a chance to examine the ring growth pattern of a tree that I have seen standing before it was felled. Newly pollarded trees do not reduce their annual increments, if anything they increase them, with vessel-rich wood rather than fibrous-rich. I think it is more marked in ring-porous species, but I am still observing. So it depends what the objective is. If it's maintaining the tree's vitality, I'd keep the RPA (and then some). If it's sneaking something past planning, by all means try it, but I'd be telling the client that's what I was doing and not promising ongoing vitality. Read pedantically (because that's what TOs and planners seem to do) there is no clear mechanism in BS5837 to reduce the RPA, only modify it's shape. That said, one could infer that parts c and d of clause 4.6.3 anticipate changing the size rather than the shape of the RPA. I have certainly changed it on many occasions based on soil depth. It is after all an imitation of a soil volume. Deeper soil, smaller RPA. As I say, much of this is based at looking at stumps of topped or pollarded trees I've been involved in removing. Te DBH is reflective most of all of potential for water uptake, and that is a reflection of rooting rather than crown. Re-pollard so of thn that that isn't true any more, and you've got a dying tree. I've seen that many times. They succumb to infection too in their weakened state.

Someone has commented they were there for 5 hours.

Hmm. Land owned by Scottish Enterprise, who commented that some trees would need to be felled. Preferred bidder status for redevelopment given to Flamingoland. Treees flattened, then TPO preventing the few surviving trees being felled. Stinks! I know what I think. TPO attached, which includes official justification for TPO, otherwise known as shutting the stable door way too late. 20180321-A3P-TPO-Drumkinnon-Bay_v02-for-website(1).pdf TPO-No-10-of-2018-2018-03-22-Redacted-1.pdf

https://www.dailyrecord.co.uk/news/local-news/police-hunt-men-who-butchered-12255074 Totally bizarre. This area is in full view of Lomond Shores visitor centre etc. which gets 10s of 000s of visitors a week. https://www.google.co.uk/maps/@56.0068717,-4.5929892,420m/data=!3m1!1e3?dcr=0

You mean any trees at 8cm or less DBH don't count? Branches less than 8cm coming off trees that are greater than 8cm DBH surely count? It's "aggregate cubic content", ingoring exemptions.

Good point. Oak is the king of the hazard beam. Bit of a design flaw, that. Not much chance of a mast year on a Poplar though. Some candy floss if it's even fertile.

Tim/David, I have no pics of the branch, it just looked like a standard limb removal as I was groundie for the day, and I didn't see the cracks till it was mostly in teh chipper and the heavier wood was getting ringed up. It was a fairly hefty old Poplar that had been topped severely about 15 years before, and a lower branch had gone mad, it started horizontal and stretched out for about 15 metres, curving progressively to the vertical. The section I have is about 35cm diameter, but it was in a bulge and the rest of the limb was only about 30cm diameter before and after the bulge. The bulge was in the classic hazard beam failure position, on a section about 20 degrees off hrizontal. I've always assumed beam failures are instigated by torsion due to end wind loading, rather than by dead loads.

Neither. It was approx like this in situ...

I wasn't tempted to taste. I can only imagine anything associated with Poplar would tate like Satan's 3 month old socks.

Some humbinging Pleurotus on a stinky Poplar breakage.

Nasty situation found inside bulging overextended Poplar limb at an upcurving point. Is this Poplar's answer to hazard beam failure? I plan to make a clock face out of it, if it doesn't fall apart during drying.

For what it's worth BS 8545:2014 Trees: from nursery to independence in the landscape – Recommendations says "8.4.8 All wire used for rootballing should be non-galvanized." and "Table 1.... Remove the wire cage where practicable. If this cannot be done, peel back the wire cage and hessian once the tree is in the planting pit." To me the first bit is crucial, I would be confident that non-galvanised wire would rust away quickly. When using the Platipus underground guying with the proprietary 'Plati-Mat', I think leaving the wire and hessian is preferable, to addd to the prevention of the guys cutting into the rootball, causing damage and instability.

I am looking for anyone who has got direct experience of planting and stabilising large trees (c.10m high, DBH 20cm, 2m rootballs) trees using Platipus above and below ground anchoring. Reference may be required. Inverness area. Any leads or interest from anyone much appreciated.

You don't need to go all the way to the centre. Hitting the centre would be lucky anyway. All that is really required is to know the average annual increment, and you'd probably get that from about 15 or 20 rings which will probably not exceed 120mm. Everything else can be done by extrapolation and application of the method published by the Forestry Commission. Can PM me if you need details.

Hope your parade has dried out. Perhaps you were right, or perhaps Mr H was having the day off. But the Beech/Diatrype association is a strong one, as is the Beech/Hypoxolon nummularium association. I must look more closely next time.

It' got to be quite a complex phenomenon. Hollowing of the stem will make the weight pressure on the remaining wood greater per m2, except that the crowns have usually retrenched by then and the whole thing weights afraction of its mature weight. Easy calculation if I could be bothered. But it would be interesting to see if new increments in late mature oak revert to ring porous as young retrenchment growth becomes the only foliage in the crown. Another factor might be the recycling of nutrients as a tree hollows out. For the first 500 years an oak might just be taking from the soil, but of the next 500 (give or take) it has 500 years of steadily decaying wood inside it feeding all those nutrients back into the soil. That's a pretty good pension.

Or was it Hypoxolon nummularium? Or both? It was gettign dark and I was in a hurry, only got the pictures now to go by.

I looked at a Beech last week, it had fallen apart largely due to Ganoderma but had lots and lots of K. deusta at the base. I though it had the same on a large detached limb like in these pictures, but on closer inspection it was masses and masses of Diatrype disciformis. Pic attached, not the most representative of the density of the Diatrype. Tree had Kretschmaria, Ganoderma, Diatrype, Pseudotrametes and 2 species of Stereum.