Treecreeper1961

I am currently working on a couple of BS5837 surveys and as usual issues arise. Namely, not enough space to accommodate tree RPAs and other things. It would help me if any comments on the following could be posted (nothing rude please, i'm sensitive and like trees): 1. If the RPA of a tree inhibits a development the options are: a)no development b)remove tree c)engineering solutions d)depending on the value of the tree and it's location, breach the RPA and hope it survives?????(This is ill advised of course, but in some circumstances better than removal?) 2. The BS5837 indicates it is acceptable to undertake certain work within an RPA, such as hand digging, thrust boring, pile foundations and radial trenching. These would inevitably lead to a limited loss of rooting environment an damage to some roots. In a similar context, could removal of a shallow layer of soil(250m) within the outer area of an RPA be an acceptable intrusion. Assuming the roots are mainly within the top 600mm of soil horizon removing 250mm of soil, pruning any damaged/exposed roots, replacing 250mm of soil with cellular material and clean granular infill, area of RPA impinged upon 2m of 4.5m radius. 3. Does the species and height of trees allow for reduced RPAs ( if compromise is needed)? For example, a mature Hawthorn may command a fairly large RPA. I think they are worthy of as much protection as any other tree but in reality the mechanical implications of lost roots are not as severe compared to loftier species. Thanks....

So much reading to do, such a small brain to do it with.

This suggests high tensile loading to me(taken from Pprune website, Professional Pilots Rumour Network) The fact that the shear stress is a maximum at 45 degrees to the loading axis is shown by an equilibrium diagram of a small element of material under load. The best source of these can be found in derivations and descriptions of Mohr's Circle, such as this: Mohr's Circle This shows that the shear stress is a maximum when two-theta (sorry I don't know how to write Greek letters on this thing...) is 90 degrees, so theta is 45 degrees. When a sample of ductile metal such as steel is pulled in a testing machine until it fails, the failure always exhibits a 45 degree 'lip'. In a rod, this failure has a 'cup and cone' appearance because the lip is circular. The 45 degree planes are where the maximum slippage has occurred between the crystals in the material, which is the mode of failure, and of course the slippage occurred along the plane of maximum shear stress. When you are examining wreckage from an aircraft accident, the bits that failed in tension are immediately obvious from these 45 degree features. They tell you the tensile loading direction too!

It would be interesting to know the providence of the Sorbus in Rob's photos. I don't know much about this at all and whilst the genetic theory seems plausible the only reference I have for it's occurrence suggests it is due to mechanical stress! Intriguing.

The Dendro Detective was an entertaining read, not sure it shed much light on the subject though.

This may be viewed as a waste of all your time and I apologise if that is the case but.... The purpose of this thread is to test the waters, in a purely hypothetical kind of way. So here is the question: How much demand is there for a two man freelance climbing team in Southwest Wales, from Swansea to Aberystwyth? Both climbers being motivated, hard working and keen to work to high arboricultural and safety standards. Over sixteen years combined experience in arboriculture and woodland management, holding NPTC units 38,39 and 41, MEWP and ABC Technicians Certificate. It would be really interesting to have some kind of idea of how much work there would be out there. Consider this market research:001_smile: Thanks for any input you can give.

Oh yes, nice root pics.

As described in the Updated Field Guide to VTA, "fiber buckling and bulgewood....the cross ribs are bulgewood after 45 degree sliding of the fibres along the shear planes." It may be very explainable in individuals but seems extraordinary in a group. What kind of stresses create this phenomena? The beech stem I posted previously is similar. Easier to explain on a bough with the stresses of supporting it than on what seem to be fairly upright trees. Is it something to do with local wind patterns perhaps? Will await your interpretation with interest!

Thanks Fungus. My id book says there is/has been confusion between H. petriniae and H.rubiginosum but doesn't say anything more??

Here we have an A.hippocastanum, which immediately makes me think there could be any number of things wrong with it. From a distance, it appears to have a "life belt". Closer up, this seems unlikely as the bark pattern is badly altered. This could be due to HCBC, which the tree has managed to halt,perhaps? Or, could we be looking at pruning wounds from a crown lift?

Is that the oak/s in 3 and 4 or the last picture?

Oaks in pictures 3 and 4 possibly suffering from an infestation of Badiusarbus prcticus. Although this could be a false alarm as there are some signs of recovery. I am not too sure but there appears to be the indication of reaction to "slow heartwood rotters", probably unlikely to have entered or been activated by relatively recent pruning.

Hidden treasure on your door step!

The first photo shows a heavily leaning beech with upper crown in decline. Difficult to comment whether the are any competition issues adding to the lean. There appears to be some exaggerated basal flare and this, with the crown die back, could indicate the presence of a fungi such as M.giganteus, largely confined to the central root plate and perhaps extending up the stem, thinning the shell and resulting to the swelling opposite the lean. There is the evidence of a shear crack just above the base. Little sign of bark buckling. Is this due to the thin bark, or has the shear crack resulted from the embrittlement caused by the fungal decay? All of this could be the result of agricultural practices which have had an adverse effect on the rhizosphere, compaction from stock or machinery, damage from ploughing or use of agri-chemicals.

co dom stems in close grown forest stands tend to be 20degrees and more acute open grown tension forks much wider in gape. Please excuse my ignorance and haste with these foolish questions. I am really trying to get the technicalities of these symptoms sorted in my mind.I decided to read or re-read the chatty tree thread, it's a great learning resource. As you know, I am currently in possession of the Updated VTA handbook, another great resource. The prompt for the question comes from the book, I suppose. Mattheck's description of the "outwardly arched welding seam" of the Chinese moustache led me to question whether the "active" fault was indeed that, or instead the long seam of the moustache. Gut instinct is definitely telling me there is something wrong there, no doubt about it. If it is a tension fork with no included bark, active and failing as it appears to be, what is the correct term for that, or is it just a crack? Just tell me to shut up if you want. The concept of the poorly formed or weak union becoming "active" is new thinking, or terminology at least, to me. If a compression fork is observed regularly enough, is it likely that the "activation" of the crack or split will be seen before it fails? Perhaps this is entirely dependent on wind loading. Is there any way to predict the failure of these formations? Does an active split mean impending doom? With targets(shall we say a moderately used B road) present, would you consider a reduction to alleviate stress on an active fork? Cheers.

Rain in West Wales.

4 Diatrype sp. Don't keep me dangling!

Hama, Is this a compression fork or a tension fork? Looks like a tension fork with Chinese moustache. Are there any concerns with the integrity of this particular union? What tells it apart? The angle and the seem being inward not outward?

Fine sentiments and I agree. Learning to read the language is what I aim to do. It's a exciting challenge.

Is it a fair assumption that the symptoms only become obvious when a cavity has formed, or the wood is so degraded that it is almost a cavity, as the lignin left before this has retained tensile stress? Or is that 2 + 2=5?

Is there a hint of helical growth in the stem? Increment strips reinforcing early helical crack complicated by decay?

If there is no bracket present then that probably rules out H. anossum. Is the fungi you speak of Sparissis crispa? The additional increment of reaction wood goes against what I have learnt regarding brown rot. I'm sure you have read it all before, but degradation of cellulose supposedly leads to brittle fracture with the stem retaining rigidity and hence the cambium unaware of the impending mechanical doom. Alternatively, the lack of rigidity but retained ductile strength created by white rot leads to increased flexing of the stem and the cambium senses it and responds, by reinforcing the zone, returning the state of uniform stress if possible. Now, I know this is recognised wisdom, but what I am starting to suspect is that it is not necessarily set in stone. Can trees sense and respond to the loss of equilibrium caused by brown rot? The Fistulina thread suggests so.

Can I have a guess? There seems to be quite a lot going on there. The corrective phototropic growth seems to suggest the tree slumped forward quite a lot with the tree responding really quickly. It has obviously managed to correct it and must have sensed the increased flexing in the stem. That leads me to think it must be a white rot that created the extra flexing, if a brown rot caused such a lean it would surely have led to fracture. I would have a guess at Heterobasidion anossum as the fungi sp. but I don't know if that fits as it is supposedly a root rot. I reckon there is a wound on the left side of the butt that could be the point of entry, maybe mower damage?

Yeah, schoolboy error. I did have it down as Alder Bracket but got a bit confused:confused1:

What gives that then? The host sp. or the fungi features?