Interesting Biomechanics

[Bundle 2]

Superb photos. How quintessentially "English" an image that is!

[Tony Croft aka hamadryad]

Superb photos. How quintessentially "English" an image that is!

 

Thanks Tim, what was really interesting in this particular location was that the air temps in this grove where so much lower than surounding ambient temps i felt frozen!

 

Trees- natures air conditioning units.

 

Quiet appropriate with the current avenues and buelevards seminar at kew on the 24th, anyone going on this?

[David Humphries]

Found an avenue similar on the way back from Cornwall yesterday, there was one tree inparticular that caught my eye, and a finer example of torsional growth could not be found.

 

[]

 

That Beech is superb Tony, as impressive as anything we saw at Stav

 

 

 

 

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[Tony Croft aka hamadryad]

That Beech is superb Tony, as impressive as anything we saw at Stav

 

 

 

 

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I couldnt agree more, this is why i like back country B rds and following my GPS via as straight a line as it can muster, takes me down roads like these all the time, and i find some gems everytime.

 

I found a corking working pollard ash too, massive girth and the regrowth no more than 5-6 inch Diameter.

[Tony Croft aka hamadryad]

The many varied strategies of trees to cope and work with bio mechanical loads and stresses simply fascinates me, the torsional thing really is my thing though, i just love the strategy, and seeing those old ancient birches at Staverton really got my juices flowing!

 

although it can generate a weakness overall it is a great strategy, as it makes resonence easy to cope with unlike a more verticly aligned growth of fibres.

 

i liken this torsional growth to those of the fibres aligned in the S1 S2 and S3 layers, each layer laid in a differnet wrap, the straight growth of youth S1 imagine and older subsequent growth exposed to wind loading via a broad crown in peak dominaence laying down a helical wrap to cope with the new momentum in its form.

Edited June 20, 2010 by Tony Croft aka hamadryad

[Tony Croft aka hamadryad]

Whilst up at Staverton on our way to a rather nice pub for our tea me and monkey spotted this Ash, I commented that i thought, nah I lie! I said that one has DEFINATELY got Hipidus, and the next time we passed it I pulled in to confirm it. whilst i was busy looking for a sign of Hispidus David spotted a rather unusual branch adaption, and we were stunned by its complexity.

 

I have pondered this ones history for some time, it is rather special, and will leave it for others to inteprate before I say any more, as i dont want to bias any thoughts you may have:thumbup1:

 

Oh and of course, I did find a Hispidus bracket! who needs a fruit body when the body language of trees tells us what we need to know eah!

 

 

[David Humphries]

So.....as I can't even remember what we said on the site, (to much buzzing around in the old grey matter from what preceeded it) I read it, that we have helical ribs, reinforcing internal radial cracks, caused by torsion.

 

Thus, branch is forced into a twist, cracks along (rays?) which may have been open at some point, occluded, and eventually grown over by this adaptive rib.

 

Though last three shots still puzzle my poor little brain.

 

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[Bundle 2]

Nice one David...these are much better images , I was gonna say "we can see whats going on now" In a way of course we can...but a mechanical explanation of the last two has me wondering for the moment. Mmm. Good posts.....cheers.

[Tony Croft aka hamadryad]

I would like to add something to the theories, i reckon a high loaded hay wagon has been going down this route year on year!

[Cassian]

G day - Relating to the grafted Oak, I would like to suggest that the upper limb has cracked as a result of compressive load (as opposed to tension) or being lifted by the lower branch.

 

If so, this is a very good indication of pronounced reactivity on behalf of the oak (lifting a double load?) and is an unusual example of hazard beam crack formation as a result of a grafted branch and pronounced compressive load.

 

In my experience of hazard beam crack formation in Australia with trees such as Corymbia & Eucalyptus (the main Genuses of tree Australia wide) HBC's are formed where there is a lack of tension wood and pronounced compression wood (or supporting wood as Mattheck has recorded with broad leaved trees).

 

The oak and Mattheck’s records (Ref: Broad leaved trees & The Face of Failure page 144-145) demonstrate a link to HBC formation and compressive load. Also in my experience of storm damage (2008 Gap storm Brisbane, Ref: ETS Energex Gap Storm Report) HBC formation also occurs subject to major under drafts caused by high winds which lift branches, again compressive load plays a role.

 

The beech pictures are exceptional, I have recorded a number of instances where Gums (mostly Corymbia) have produced substantial grafts above V forks. In the case of the beech did you observe sign of potential mechanical constraint at the base of the grafted limb? Judging by one of the photographs there looks like signs of inclusion.

 

Wonderful find - Best regards Cassian