Wind Damaged Conifer Observations

Jomo

Jomo

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Not the first time it's occurred to me by any means, but lateral leaders are far more prone to failure when the wind blows them up rather than down.

Now that being the case may well be common knowledge, but I don't recall Shigo or Harris writing on it.

I noticed long ago that little conifer branches broke easier by hand bent upwards, not surprising the same would hold true for bigger laterals, but have not heard or read of it being scientifically proven with dynamometers n stuff.

Have you?
 

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Around here, the wind blows sideways:)

I have noticed it's easier to break a branch by pushing up, rather than pulling down, in some cases.
 
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  • #5
Well I guess it's a growth characteristic of lateral wood that distinguishes it from veritical trunk wood?

Look at a cross section of Lat wood and the compression growth side's substantially bigger than the tension, lopsided n asymmetric.

Where as a cross section of vert wood's far more symmetric, with the first year of growth's ring smack dab in the middle, better equipped to withstand flexion from any direction.

Jomo
 
I think you have to take species in consideration as well. Don't see that much breakage in say Ponderosa and Jefferys, yet more true with Monterey or Stone pine. And gray pine breaks side or down more due to tip weight, but the twisted grain make more of a spiral tear that looks like a whirl wind got it.
 
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  • #7
My impression's that messin with a conifer's natural branch proximity sequencing's detrimental to a branches ability to withstand highwinds from unexpected directions. Like a buddy system allowing a closely spaced grouping to withstand what a lone individual branch can't.

Kinda like the trees are considerably smarter than we give them credit for?

Jomo
 
It is to do with the way the tension and compression wood grows. From memory their is only a small amount of tension on top and a lot more compression on the bottom.
 
Yep, conifers add compression wood, hardwoods add tension wood. Y'all probably knew that already though....
 
Jomo said:
My impression's that messin with a conifer's natural branch proximity sequencing's detrimental to a branches ability to withstand highwinds from unexpected directions. Like a buddy system allowing a closely spaced grouping to withstand what a lone individual branch can't.

Kinda like the trees are considerably smarter than we give them credit for?

Jomo
Click to expand...

I definitely agree with that. Not only does "wind thinning" on conifers by tree workers weaken individual branches it also introduces more shear force to the trunk, increasing the chance for a blow down.:|:
 
I often wonder about that Jomo, when thinning a tree, one has to look at the whole tree, to see what growth is where and why. Just cutting it off because it thins it out without accompanying observation is maybe a recipe for future failure.

I get especially thoughtful when taking out accumulated deadwood from inside macrocarpas and cypress...but so far so good with the ones I have cleaned out. I definitely leave dead wood where it is supporting live, and look to reduce weight on exposed live branches that may not have all that surrounding dead wood anymore.

The dynamics will for sure have changed, where the wind may have tended to go around more than through a tree with a lot of dead stuff inside, by removing it now more wind goes through, but also causes remaining live branches to sway in a different manner.
 
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  • #13
Yeah Berm, dealing with landscaped from container trees is more challenging, in terms of the whole tree toppling in high wind, after a week of rain, and 90 mph wind gusts.

My job today was a largish Stone pine, leaning too hard on smaller Stone beside it, over all the utility feeds to the house.

Fresh scrapage on the smaller Stone indicated the bigger one muscling down on it was lifting it's rootball.

Told the client big boy needed to go to be sure the whole mess didn't come down n take out the utility drops.

Sentimental value age of the old tree's prominence in the front yard, left me with a client desperate for another option than removal.

So being february I got downright brutal and a third weight outta big boy, every leader crowdin the little whacked off or back severely, then thinned both trees out somewhat brutally.

Big boy did lift up a bit straighter, not necessarily a good sign.

If they survive being brutalized is an open question.

I kinda hope the bark beetle finishes them both off, so I won't have to worry big boys iffy root plate liftin again in the next high wind.

Jomo
 
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