Deodar thinning, are we getting it wrong?

[Mick Dempsey]

2 minutes ago, kram said:

From the other side: looks to me that its been topped in the past as theres a large number of parallel stems.

Does look like that, agreed.

Conventional wisdom would suggest weak attachment points snapping out rather than the whole tree failing.

Probably someone  will link the topping with the whole tree failure

 

[devon TWiG]

Noticed the breaking apart of the crown on many Monterey cypress in my area due ( I believe ) to overthinning and or deadwooding ...my theory is that the branches are being pushed apart at forks due to wind being able to pass through the crown of the tree which it did not before ...a bit like thinning a woodland ....

[Dan Maynard]

My neck of the woods has Cambridge colleges, they are obsessive about deadwooding everything. One of the colleges does have quite a few deodars and I would say branch failures are not unusual, but what we don't have there is a comparison to say what would happen if we didn't deadwood them the whole time.

[Dan Maynard]

Agreed though they seem to fall to bits rather than fall over.

 

When was that car parking put in? Blue car looks pretty close.

[kram]

The oldest 2008 photo shows a wall which is gone in later photos.

We can probably assume when the wall was put in, roots may have been cut for a foundation or slab? Wonder if they removed foundations or just removed above ground when that went.

 

Very little roots where the wall once lived. Tree that size should have roots stretching much further out. I believe thats the cause, sorry nothing to do with the pruning

 

 

Somone with more experience should tell the guy and family that got hurt, perhaps they can claim proper compensation from the owners.

Edited Saturday at 20:03 by kram

[Mick Dempsey]

Interesting spot. 

[Pete Mctree]

I have seen quite a few branch failures due to pruning - mainly heavy thinning or lions tailing. It does change how a branch moves and dissipates energy which leads to all sorts of issues. Never really associated deadwooding with failure, thats a good piece of observation 

[monkeybusiness]

That rootplate is tiny in relation to the size of the tree - I’d be surprised if there wasn’t evidence of root decay there. 

[Acer ventura]

You might find this recent post from our social media useful...

 

𝗗𝗲𝗮𝗱𝘄𝗼𝗼𝗱 𝗥𝗶𝘀𝗸-𝗕𝗲𝗻𝗲𝗳𝗶𝘁
We're elbow deep in v2 of VALID's risk model, and the Tree Risk App you use to carry out a Detailed Assessment.
 

One of many substantial improvements in v2 is 𝘩𝘰𝘸 𝘸𝘦 𝘮𝘢𝘯𝘢𝘨𝘦 𝘢𝘯𝘥 𝘢𝘴𝘴𝘦𝘴𝘴 𝘵𝘩𝘦 𝘳𝘪𝘴𝘬 𝘧𝘳𝘰𝘮 𝘋𝘦𝘢𝘥𝘸𝘰𝘰𝘥.

As with the Policy section in our Tree Risk-Benefit Management Strategies. Let's take an ISO 31000 approach and 𝘌𝘴𝘵𝘢𝘣𝘭𝘪𝘴𝘩 𝘵𝘩𝘦 𝘊𝘰𝘯𝘵𝘦𝘹𝘵.

First…

𝗧𝗵𝗲 𝗕𝗲𝗻𝗲𝗳𝗶𝘁𝘀 𝗼𝗳 𝗗𝗲𝗮𝗱𝘄𝗼𝗼𝗱
𝗛𝗮𝗯𝗶𝘁𝗮𝘁
For a range of organisms, like insects, fungi, lichens, mosses, birds, mammals, and amphibians

𝗜𝗺𝗽𝗿𝗼𝘃𝗲𝘀 𝗧𝗿𝗲𝗲 𝗦𝘁𝗮𝗯𝗶𝗹𝗶𝘁𝘆
In particular, mass damping (dissipating wind load). Here are 3 ways.

𝟭) 𝗠𝗼𝗿𝗲 𝗠𝗮𝘀𝘀
Deadwood adds weight. This increases inertia, which reduces sway. Especially in the upper crown.

𝟮) 𝗚𝗿𝗲𝗮𝘁𝗲𝗿 𝗦𝘁𝗶𝗳𝗳𝗻𝗲𝘀𝘀
Deadwood is stiffer than live wood. It dances to a different rhythm than live wood in the wind. This out-of-phase syncopation helps dissipate kinetic energy.

𝟯) 𝗜𝗿𝗿𝗲𝗴𝘂𝗹𝗮𝗿 𝘀𝗵𝗮𝗽𝗲
Helps the tree smooth out the strain and stresses from wind loading.

𝗧𝗵𝗲 𝗥𝗶𝘀𝗸
What does the data tell us about the risk from Deadwood falling?

We know our annual risk of being killed or seriously injured from ALL trees or branches falling is 𝘭𝘦𝘴𝘴 𝘵𝘩𝘢𝘯 𝘰𝘯𝘦 𝘪𝘯 𝘢 𝘮𝘪𝘭𝘭𝘪𝘰𝘯. That's so low, we're at greater risk driving on about a 400km/250mi round trip to visit friends for a weekend than from branches or trees falling over an entire year.

Nearly all these deaths and serious injuries are from live wood. The risk from Deadwood HAS to be much lower.

The overall risk from Deadwood falling is mind-bogglingly low. An annual risk somewhere south of 𝙤𝙣𝙚 𝙞𝙣 𝙤𝙣𝙚 𝙝𝙪𝙣𝙙𝙧𝙚𝙙 𝙢𝙞𝙡𝙡𝙞𝙤𝙣.

𝗗𝗲𝗮𝗱𝘄𝗼𝗼𝗱 𝗖𝗵𝗮𝗿𝗮𝗰𝘁𝗲𝗿𝗶𝘀𝘁𝗶𝗰𝘀
Deadwood has already shed its lower order twigs, shoots, and branches. It falls in smaller lengths than live wood. If it falls, the footprint is much smaller than an equivalent diameter branch that's alive.

Deadwood is not only 𝘴𝘮𝘢𝘭𝘭𝘦𝘳 than live wood, it's 𝘭𝘪𝘨𝘩𝘵𝘦𝘳.

As Deadwood provides habitat benefits.

And Deadwood reduces the Likelihood of Failure of branches and trees.

Why is so much 𝘵𝘪𝘮𝘦 𝘢𝘯𝘥 𝘮𝘰𝘯𝘦𝘺 spent on removing the benefits from Deadwood?

In v2 of VALID's risk model. Deadwood under 10cm diameter is a Tolerable or Acceptable risk.

We're only going to carry out a Detailed Assessment in Very High, High and Moderate Occupancy where Deadwood is 10cm diameter or more, and longer than 1m.

𝗩𝗔𝗟𝗜𝗗 - 𝗜 - 𝗦𝗽𝗲𝗰𝗶𝗲𝘀 𝗣𝗿𝗼𝗳𝗶𝗹𝗲
When you make Likelihood of Failure decision about Deadwood with VALID v2. We'll pre-colour V, A, L, and D for you.

You make a decision about I for IDENTITY, and whether the Species Profile is green or red. That will determine whether the risk is 𝗧𝗼𝗹𝗲𝗿𝗮𝗯𝗹𝗲 or 𝗡𝗼𝘁 𝗧𝗼𝗹𝗲𝗿𝗮𝗯𝗹𝗲.

Edited Saturday at 20:37 by Acer ventura

[AHPP]

This is a good thread. I don't know enough to contribute meaningfully but I make most tree decisions with, "Man plans and god laughs." as a starting point.

 

Rob Rainford posted a long time ago about pruning affecting the mechanical characteristics of unions and collections of unions, weight being thrown back and forth, twanginess etc. All about how one thing can have three dimensional knock-on effects. Really interesting. Must find it.

 

@RobRainford