Interesting Biomechanics

[OakStag]

Not sure if this is the right place but a awesome hawthorn. Shame it had to be a stump.

[jfc]

Scots pine, between a rock and a hard place!

[ABtrees]

Not sure how this is still standing.  Here's a couple of pics of what appears on one side to be a pretty ordinary oak.  Once you get round the other side however it's pretty much hollow !  I reckon its a lightning strike that set fire to the inside of the tree (last pic). The tree itself is around 1.3m DBH (I stood inside it for that last pic) and circa 18-20m tall.  The bit that I don't get is the weight/c of g is all wrong -heavy limbs all over the one (good side). The forces at play must be huge.  I'm also not sure why the dead bit (on the bad side) looks as though it has compressed to crack in the middle (maybe under its own weight?). When it goes it'll be big and fast - I've been waiting 12 years so far ! 

[Steve Bullman]

Its amazing how trees keep standing

[David Humphries]

3 hours ago, ABtrees said:

Not sure how this is still standing.  Here's a couple of pics of what appears on one side to be a pretty ordinary oak.  Once you get round the other side however it's pretty much hollow !  I reckon its a lightning strike that set fire to the inside of the tree (last pic). The tree itself is around 1.3m DBH (I stood inside it for that last pic) and circa 18-20m tall.  The bit that I don't get is the weight/c of g is all wrong -heavy limbs all over the one (good side). The forces at play must be huge.  I'm also not sure why the dead bit (on the bad side) looks as though it has compressed to crack in the middle (maybe under its own weight?). When it goes it'll be big and fast - I've been waiting 12 years so far ! 

One aspect of it maintaining its structural stability is that whilst its still got a functioning canopy creating energy, through photosynthesis, it will have been putting on reactive wood where it needs it over a long time frame.

So those flared tension buttress roots are almost certainly bigger and more developed now due to the unbalance nature of the trees weight and the load that the wind places on it.

 

You may need to wait another 10..20..30..40  years before it fails. 

 

....but then again, it may be down next week 

[ABtrees]

10 hours ago, David Humphries said:

One aspect of it maintaining its structural stability is that whilst its still got a functioning canopy creating energy, through photosynthesis, it will have been putting on reactive wood where it needs it over a long time frame.

So those flared tension buttress roots are almost certainly bigger and more developed now due to the unbalance nature of the trees weight and the load that the wind places on it.

 

You may need to wait another 10..20..30..40  years before it fails. 

 

....but then again, it may be down next week 

I guess the same applies to these .... because they look (to my untrained eye) like the could have / should have fallen over by now !

Struggled to get the exposure - right backlit trees on a sunny day hence crappy pics - oops. Pic 4 is close up of 3.

 

They are obviously old pollards and I guess my question is: would it be better to take some of that weight off (i.e. reduce them back to the pollard - not too close) or is that likely to do more harm than good ?  I'm guessing the first one has had its centre rotted out as a result of the (original) previous pollarding ???  Thoughts and advice gratefully recd.

[David Humphries]

10 hours ago, ABtrees said:

I guess the same applies to these .... because they look (to my untrained eye) like the could have / should have fallen over by now !

Struggled to get the exposure - right backlit trees on a sunny day hence crappy pics - oops. Pic 4 is close up of 3.

 

They are obviously old pollards and I guess my question is: would it be better to take some of that weight off (i.e. reduce them back to the pollard - not too close) or is that likely to do more harm than good ?  I'm guessing the first one has had its centre rotted out as a result of the (original) previous pollarding ???  Thoughts and advice gratefully recd.

Cutting back to the original bolling would likely be the end of them, there'll be very poor starch reserves left at the base of the poles as they are long lapsed from cutting. 

Light (or lack of) will be a concern , as they appear to sit within a fairly dense canopy? 

 

Guessing they're hornbeams?

 

Best set way to stabilise/restore them (if there is desire and/or resource) would be a multiple phased reduction and haloing the surrounding trees.

[ABtrees]

27 minutes ago, David Humphries said:

Cutting back to the original bolling would likely be the end of them, there'll be very poor starch reserves left at the base of the poles as they are long lapsed from cutting. 

Light (or lack of) will be a concern , as they appear to sit within a fairly dense canopy? 

 

Guessing they're hornbeams?

 

Best set way to stabilise/restore them (if there is desire and/or resource) would be a multiple phased reduction and haloing the surrounding trees.

Thanks for that David.  You're right about the lack of light and the fact they're Hornbeams - got to be one of my favourite trees !  I have lots of them and maybe 20 - 30 are these old (neglected) pollards.  In days gone by they grew /used them to provide the 'teeth' for the gear in a water mill mechanism presumably on the basis that the wood is so hard wearing (but in the event of a jam would shear unlike metal to metal).

The lack of light has caused them to go long and straggly (as have their neighbours) so the haloing could be interesting!  As for the multiple phased bit, do you mean take a length off each pole, leave a couple of years and repeat rather than cut one pole right back (say to within a couple of meters) let that recover and then do the next pole etc.  If the former, how much should I look to reduce by, on the first reduction - is the starch issue based on the age (i.e. diameter of the pole) or is it distance from the foliage ???  They seem fairly hardy trees - my bonkers farmer neighbour cut a 18 - 20 m tree down to 3m (diameter 50cm) about 3 years ago -  its now flourishing !

[daltontrees]

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.

[David Humphries]

2 hours ago, daltontrees said:

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.

Were the completed radial cracks predominantly in tension or compression Jules?