Redwoods own weight damaging tree's own tissue ??

[M.D. Vaden]

Not sure if I'll hear much back. But I email Robert Van Pelt in WA, about big trees like redwoods, as to whether there is any research about old trees causing liquefaction, or, big trees constricting their own undersides with the immense weight.

My hypothesis, is that they do, and may be the reason why many old redwoods have been hollow beneath, lacking healthy tissue there.

If my facts are somewhat correct, a tree like Lost Monarch should weigh about 3,000,000 pounds, for just the trunk and main stem weight - more for foliage. And even more for rain weight.

That's a cross section of 530 square feet, or 76,400 square inches. Meaning about 2/3 of the weight of one bag of concrete pressing on every single square inch. About 40 pounds per square inch.

My computer is on a table that's 30" x 50". To apply the same pressure to that size table top, would mean stacking 1000 to 1200 bags of concrete over it.

Home Depot man told me there are 42 bags of concrete per pallet. So that would mean a vertical column stack of 23 to 28 PALLETS of concrete over my table top, to exert the pressure pressing downward in a giant coast redwood trunk.

In the trunk is narrower, like Adventure tree, and weight somewhat comparable, then the pressure would be even greater.

After seeing tree cambium get restricted and damaged by rope, small branches, roots and other obstacles, I can't imagine cambium standing a chance beneath that kind of pressure.

Anyway, this is a recent brainstorm.

 

[Crofter]

Interesting how the cell structure can stand it. Talk about compression wood! The kind of force in the other direction is the limitation on suspended cable hoists in deep shafts by the cables own hanging weight approaching its own tensile strength.

 

[John Paul Sanborn]

As Mattheck says, trees are self optimising, they handle the loads they haves and add wood only where needed.

I think what you are seeing is very old damage in remnant stands of trees that were not worth logging out, fire lightning, a felled tree hit it one the way down...

 

[M.D. Vaden]

As Mattheck says, trees are self optimising, they handle the loads they haves and add wood only where needed.

I think what you are seeing is very old damage in remnant stands of trees that were not worth logging out, fire lightning, a felled tree hit it one the way down...

I'm thinking about trees like Dyerville Giant, when they all over, are hollow underneath the middle.

I don't think redwoods can form compression wood on the bottom. With three million pounds pressing down, I see no way for expansion of cambium on the bottom side. Possibly on the top side of the trunk flare and in some of the root system.

But it would be very interesting if someone took soil samples after a giant fell to test the degree of compaction, and take core samples from the underside of the roots near the stem if any wood was intact.

From what I've read, the Lindsey Creek Tree redwood of about 1905, would have weighed 7,000,000 pounds, basically on par with the Saturn V rocket.

 

[rmihalek]

Why do you think the cambium be a load-bearing component of the tree?

 

[Ekka]

Oh my! :jawdrop:

Tree cells can take upwards of 140psi per cell, not per square inch but per cell. Those calculations you have shown are tickling it.

How many trees do you see collapse on their hinge wood when felling? Oh I forgot, you dont do tree work, you're one of those pen pusher arborists with a ISA ticket.

Furthermore the interior of the tree takes a lot of the weight whilst the exterior grows, each new ring is relieved of the previous ring's or year's pressure. The new cells aren't under the same stress.

Many trees hollow in the middle from the pith outward, little defence and often caused from tap root die back.

Basics of physics, every action has an equal and opposite reaction, once the tree has fallen relieving it's weight on the soil how are you going to measure pressure ... it's gone?

Tree cells grow around things when the pressure is too high.

opcorn:

 

[B-Edwards]

Why do you think the cambium be a load-bearing component of the tree?

I thought the exact same thing until he said "underneath" . Very interesting question. I am sure you guys know a leaning pine will grow support wood underneath and a leaning Oak will grow it on top. Physics is so cool.

 

[M.D. Vaden]

I thought the exact same thing until he said "underneath" . Very interesting question. I am sure you guys know a leaning pine will grow support wood underneath and a leaning Oak will grow it on top. Physics is so cool.

Exactly Edwards.

The Eric Frie photo misses the point. It's merely one more image showing that cambium can't expand against weight and pressure. Go post that pic on an Australian site under the heading of "loadbearing and wood". This topic is dealing with cambium expansion under enourmous pressure. And all that pic shows, is that cambium quit expanding under the pressure of the concrete.

Yes Edwards, that's the essense of what I wrote.

If a tree like Lost Monarch or Del Norte Titan have 3 to 4 million pounds bearing down on the trunk, then for cambium to grow on the underside downward, would be comparable energy-wise to tree roots having to heave a sidewalk with concrete like 20 feet deep. That would be like cambium tissue having to lift the foundation and side of a multi-story brick building. Except that this topic is referring to the underside.

On the center underside, the soil could becomce so compact, that gas exchange is virtually null and void. And then what effect would that have?

It would not be a limitation for some trees. But then at which weight would it become a limitation? Likely based on height to a large degree, because a tree 300 to 350 feet tall is going to stack more weight directly above. If my calculation is right, that 30 to 50 pounds per square inch is exerted downward, then lets' compare this to a vehicle driving over soil.

I think that my Chevrolet Silverado has a "footprint" of about 50 square inches per tire - rough estimate. So let's say 200 square inches for all 4 tires. That quad cab loaded with tools is about 5000 lbs. Divide by 200. That's slightly over 25 lbs. per square inch.

If I loaded (if possible) 5,000 lbs more onto my truck, and drove across the soil of our yard, that would be comparable to the pressure a redwood may be exerting with it's own weight.

Even use a forklift for an example. If you drove a forklift across your soil (moist), that would compact soil a lot. I think a forklift would apply about the same pressure per square inch as a 5000 pound trunk with 5000 extra pounds loaded.

Now, that last bit was about "compaction" which I'm interested in too, but the main thing I opened with was pressure and restriction of growth. The two things may be related regarding the development of a tall tree's underside in the center.

I'll recheck the math later in the day too.

 

[M.D. Vaden]

The text should have explained it, as Edwards pointed out, but here's a couple of images to go along with the topic. The arrow points to the area I'm referring too:

 

[M.D. Vaden]

Why do you think the cambium be a load-bearing component of the tree?

I'm not really looking at this according to it's "load bearing" capacity. But in relation to it's health and adding of strength. Or, deterioration. If the pressure below a huge redwood prevents cambium from expanding downward, and suppose the cambium even dies and starts to disintegrate, then that area can start to weaken. This could be an added limitation to how long one of these trees can stand.

 

[lh3]

Are you suggesting, theoretically, that if you, somehow, helped relieve or support some or a majority of the wieght of one of these trees, that a tree could grow unlimitedly or at least significantly larger and taller?

 

[B-Edwards]

I have read there is also the concern about the tree being able to transport water at these heights. These trees are unreal!

 

[Ekka]

Exactly Edwards.

The Eric Frie photo misses the point. It's merely one more image showing that cambium can't expand against weight and pressure. Go post that pic on an Australian site under the heading of "loadbearing and wood". This topic is dealing with cambium expansion under enourmous pressure. And all that pic shows, is that cambium quit expanding under the pressure of the concrete.

LOL, you seem to approach this issue with the same arrogance as your expertise on websites.

Lordy ... when landscrapers become scientists in trees after simply watching real tree work.

So you suggest that your scenario is different? Wow, this will be real good. Lets see, hmmm,

cambium quit expanding under the pressure of the concrete

Gee, I wonder what all that stuff is then that grew outwards, and just so your linear brain comprehends things in different perspectives I wonder what happens if we rotate the picture and then stop to think that the concrete might be the ground beneath the tree.

Furthermore trees grow on the outsides, and up .... your "theory is suggesting trees grow downward directly beneath, maybe you expect to find a 300' bole beneath a 300' tall tree.

 

[moss]

In medical diagnosis a common mistake for less experienced doctors is to diagnose a rare disease or syndrome before ruling out the most common possibility. The antidote to this way of thinking is summed up in this helpful phrase "When you see a zebra, think horse" (at least when you're not on safari in Africa).

Considering that heart rot is the most common and expected structural pathology in "elderly" trees I don't see the same in Coast Redwood as being unique. It's interesting that many large old Bald Cypress are totally hollow and keep on going, some have theorized that for a very large old tree the hollow bole actually reduces mass and allows the tree to keep standing as it gets into the later phases of its life cycle. The outer cylinder remains strong, as long as the roots are healthy the tree stands. The reason the redwoods in the photos fell is likely because of root rot, there are many still standing with hollows in the bole.

The weight of large redwoods (and Giant Sequoia) may be a red herring. I'm no expert but a tree seems to be a "tensegrity" structure, the load is distributed. You may find if you were able to test soil compaction under a live redwood that there is much less compaction than expected compared to the effect of dead weight from a static vertical column. The load is carried and dispersed throughout the root structure. For all we know the Coast Redwood may sit relatively lightly on the forest floor.
-moss

 

[M.D. Vaden]

In medical diagnosis a common mistake for less experienced doctors is to diagnose a rare disease or syndrome before ruling out the most common possibility. The antidote to this way of thinking is summed up in this helpful phrase "When you see a zebra, think horse" (at least when you're not on safari in Africa).

Considering that heart rot is the most common and expected structural pathology in "elderly" trees I don't see the same in Coast Redwood as being unique. It's interesting that many large old Bald Cypress are totally hollow and keep on going, some have theorized that for a very large old tree the hollow bole actually reduces mass and allows the tree to keep standing as it gets into the later phases of its life cycle. The outer cylinder remains strong, as long as the roots are healthy the tree stands. The reason the redwoods in the photos fell is likely because of root rot, there are many still standing with hollows in the bole.

The weight of large redwoods (and Giant Sequoia) may be a red herring. I'm no expert but a tree seems to be a "tensegrity" structure, the load is distributed. You may find if you were able to test soil compaction under a live redwood that there is much less compaction than expected compared to the effect of dead weight from a static vertical column. The load is carried and dispersed throughout the root structure. For all we know the Coast Redwood may sit relatively lightly on the forest floor.
-moss

This is still hypothesis - not sure if it's a diagnosis yet. Would have to have more soil samples and stuff.

Basically, when a few of the giants fall over, you will see most of the footprint that the weight could have been dispersed too. The weight will not be dispersed downward on the perimeter of the root system. In the middle, and outward for a short distance. How far out, still a question, and that's why this is still a hypothesis.. I think that soil samples from off the rootball and from soil underneath, would be some useful clues.

I don't think we would be suprised by how light a redwood sits on the forest floor, as much as how heavy it may sit. The big ones are in the 3 to 4 million pound range. But yes, it could be a red herring. And I don't think it's been studied much if at all. So far, Van Pelt replied as if it may be a whole new angle of thought.

One tree I'd like to take a gander at again, is the one in "Atlas Grove" called Gaia. It's got a fire cave in it's lower side, and down into the center or the root plate. So all it's weight is pushing down on an incomplete thin cylindrical shape of wood and tissue.

 

[M.D. Vaden]

Oh yeah...

In Ekka's pics, again..

The cambium in those pics is not growing toward the directiion of the beam, but out and away from it.

I already pointed out with the redwoods that tissue can grow where there is no restriction - like the top of the roots, sides of the trunk.

Hey Moss, one more thought,

There was one stump fallen near the Grove of Titans that had some obvious restriction of growth beneath. It was a fallen stump. Part of the restriction was river rock. But not all the area. Next time down there, I may take some better pics of areas under the old root system.