Windstorm outcomes?

I just wondered if anyone had any observations about what kinds of city trees had been most affected up and down the west coast by the recent windstorms. The Sun had a photo of some big deciduous trees uprooted. Of course it was largely conifers in Stanley Park, and at one place I saw a big conifer, a very dense one, apparently uprooted - I'm going back tomorrow to get a photo if I still can.

 

Arthur Lee Jacobson has a casualty report on his web site, in the part that talks about Trees of Seattle - Second Edition.

 

I have seen many mid trunk / canopy failures of Alder, many root plate failures of western redcedar and douglas fir. some branch failures of hawthorn, crabapple and douglas fir. also noted I have seen some failures of branches on weeping willow, catalpa species and red oak. some splitting and 'opening up' of leyland cypress and multi trunk western red cedar. Many smaragd cedar hedges with bent limbs, english laurel with bent limbs. Birch with bent limbs and/or trunks. pines with mid trunk failures. and one london plane ( my parents place) with a fairly large limb failure, big enough to smash both their cars :(

 

I second Jimmyq, I also noted that many conifers lost a few major limbs, other than the Western Red Cedars and also many Apple trees, lost major limbs and some were uprooted and Cherry trees,(flowering & Fruit bearing)lost many of their limbs. The numerous Liquidambars,(Sweet Gum,Storax) that are used in many street settings,institutions also lost many branches, to the point that they will probably have to be replaced. Mother natures pruning.

 

Liquidambar, yes, I forgot to mention them. MAJOR damage to them in burnaby area. limb loss, leaders broken out. seems they still had a few leaves on them which may have caught up the extra snow to do the damage. They look like inside out turned umbrellas, branches come out from the trunk and about halfway along their length they have a fold and turn groundward. I will try to get a pic of some nearby unless the cityy guys have cleaned them up allready.

 

Wow - crushed both their cars? Ouch - I presume they weren't in them. Then there was the Hemlock shown in The Province that chopped a house in two. Fatalities were avoided there when the family's dad decided they'd be better off in the basement.

The trees I saw down, which may have been cedars though I am still never clear on what kind of tree one is actually talking about - isn't red cedar a juniper? - happened to fall due east across neighbours' front yards rather than onto neighbours' houses.

What exactly do you mean by "root plate" failure? Something like this? The root ball can just be seen behind the chunk lying foremost in the first photo, and more clearly in the second.

 

western red cedar is Thuja plicata, indeed not a true Cedrus. As for root plate failures, exactly, the failures are labelled as rotational or hinge failures and technically they are a soil failure, the soil failed to hold the tree up, rather than a tree failure which would insinuate the tree was unable to take the strain or pressures exerted upon it. kind of techie treenerd talk but, some folk may be interested. :) Generally soil failures happen when the soil is above field capacity, or supersaturated due to prolonged or heavy rainfall and lack of time for percolation. When the roots of the trees are using mud for stability vs packed soil, their strength is the same but the medium they are encased in becomes highly unstable.

 

Karin's cedars are Chamaecyparis lawsoniana 'Erecta'.

 

Thanks for the ID Ron. I'm interested in these particular trees because they are identical to the large conifer I live under, which I've tentatively identified as Ch. lawsoniana, but I didn't get to a cultivar. Incidentally we had a Christmas present from my neighbour in the form of agreement to have the tree taken down.

 

some shots from a couple days ago in confederation park in burnaby. Failed Robinia and Thuja plicata

 

more shots, failed Alders. and a failed Alder branch with a cute little yellow fungus or slime mold growing on it. as well as a small bracket fungus.

 

I've thought Karin's tree was probably an 'Erecta' from the start, believe I may have posted as much.

 

Our turn tonight, force 11 on the shipping forecast today . . . have to see what's down tomorrow.

All the new year celebrations here are cancelled, they don't want fireworks blowing into peoples' faces, etc.

 

Great photos, Paul.

For the record, Ron, I don't think you ever did post that cultivar name, at least not on this thread: http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=13856 but maybe somewhere else. It's not like I rarely mention it or anything.

Good luck Michael!

 

Not too bad in the event - not seen any trees down today.

 

By the way Paul, I meant to say thanks for the technical explanations of reasons for failure. I have heard similar info previously (soil becoming mud and thus less able to hold the roots) and have always thought that woodland soil would likely be less prone to becoming muddy, but Stanley Park would certainly negate that thought, and of course at some windspeed any soil would have inadequate holding capacity. I think I've actually heard that the wind whipping the tree can cause the roots to function like a mixmaster and actually aggravate or create the muddy conditions. Obviously it would also depend on amount of rainfall during or prior to a windstorm.

 

Seeing so many trees down does raise a heightened concern. Should these ornamental giants be allowed to grow in isolation and so close to houses?
Applying law of physics, can we predict that a tree growing in isolation is more likely to topple than if it was growing in a forest. Here is what I believe contributes to stability in a forest environment. Being immersed amongst trees of the same specie or other large trees, the roots invariably interlock and the anchorage of each tree is assisted by this interlocking. This reminds me of a floating platform that supports a high rise building.
Another factor that helps to protect forest trees is that the density of the trees act together to deflect the sweep of the wind towards the higher canopy, so the wind blows over rather than through the tree. Compare this to the sea, the storm could be raging away on the surface but underneath perfectly calm. Thus is it wise to grow huge trees for shade close to your home or to park your car close to any huge tree when you know the area is prone to storms. Maybe we all should rethink our strategy in view of our recent experience.

 

cool! it appears that I may not be the only treenerd. :)

 

Karin's 'Erecta' is not pleasing in that spot, I would cut it down myself. It is not a large example of the cultivar, nor is it a rare cultivar. Being a Port Orford cedar, prone to root rot it is no longer prevalent in commerce but is still a common landscape feature.

 

Thanks Ron, that's a refreshing thought that it doesn't even look that great where it is. And yes, I'd just read that bit about "prone to root rot" in Trees of Vancouver last night and somehow found the night's weather - quite windy and VERY rainy - not at all condusive to sleep.

Jamkh, I agree that the whole concept of urban tree strategy might need some re-examination if it's getting windier around here. In climates that have always been windy the trees simply don't get as big as some of ours are here. Although there are obviously people who will continue to choose to live near big trees (and not surprisingly given our shade needs), in an urban space the fact is that the person who grows a tree is not necessarily the one whose house it will crush if it falls. Given that the trees are somewhat unpredictable, it might be more to the point to talk not just about the trees, but about the tree-carrying capacity of surrounding buildings. As such, structural engineers as well as arborists should be in the dialogue.

 

Just like the roots all these factors mentioned are interwoven. We have quite a range of individual circumstance for our trees here, and it has enabled some observation. I have watched the roots "pump" the soggy ground next to a stream; that tree is on the ground now, in a group of 3. Two were sound (~18" diameter) and the third and largest (24") had root rot. All were D fir.

Most of our damage had obvious causes. Several (including the previous 3) were next to a clear cut (about 5 years old) and so were exposed to wind they had not grown up with. One (D. fir ~36"diam.) growing in solid ground had been topped ~30 years ago (it wasn't me!) and grown into a "candelabra" shape; all the upper parts ripped off and demolished much of the lower portion, leaving a 40' high "stump". Some of the maples had grown in a curve towards the light and were twisted off well above the ground by the excentric wind loading. Another group of maples in wet ground tipped up as a unit, with a plate of roots about 10' x 15'.

Our largest and most exposed firs (3 - 4' diameter and ~125' high) have grown up in the open and sit in well drained fairly deep soil, and had only minor branch failures, but you could feel the ground around them moving during the storm.

Ours is obviously not an urban situation, but similar factors will be at work with city trees.

Ralph

 

Each specimen has its own history and problems. Each kind has its own characteristics. Cities here could use more trees, many are being lost. Many new plantings are dumb, there's planting trees willy nilly and then there's planting good choices in suitable spots. The successful approach lies between "don't plant trees in the city" and "plant lots of trees everywhere."

 

Hmmm, interesting decision to move this thread. Not wrong, but I guess I figured tree failure is a more global phenomenon than PNW, although we may have a particular spin on it. Anyway... Ralph, those are interesting tales of trees that I appreciate having heard; you seem to have a full range of case studies at hand. Also sounds like you really know how to enjoy a storm, walking around underneath them.

Ron, I think tree policy has to address not just placement but rotation. A planting frenzy is not the right answer if the whole urban canopy will essentially mature at the same time and generate a cutting frenzy 80 years later.

 

If right trees are planted in right places there shouldn't be a mass removal later.

 

Sounds right on the genus and species. That was my first impression too.

As for variety, I can't tell from those two photos, but even the ones growing wild down here have canopies that narrow, especially when compressed on the ground.

The thick jumble of twigs sure looks like the neglected ones I've been around.

What a small root ball on that tree.

Good possibility that it was getting more moisture than needed in the growing season.