How do Trees Really lift Water to their Leaves?

Fascinating experiment showing a slice of water inside a solid wire frame.
Surface tension in water relies on cohesion in the water molecules. A droplet of water exhibits contraction of the surface water molecules due to cohesion pull. The following experiment in micro gravity shows graphically that:

1. water does adhere to a metal wire. It also shows how water in micro gravity forms a globe. What does this suggest about the proposed copper tube experiment?
2. The film of water shows the strength of cohesion and its stability is mentioned in hours rather than seconds. (that’s pretty strong)
3. Not sure what the vanishing bubbles added to the water film tells us yet, but it certainly is interesting and could show graphically how cavitations are dealt with by trees.
4. The paper towel used to draw water away from the captured water globule again shows that the adhesion to the wire does not affect the water’s ability to be drawn from the captive globule. So although adhesion is holding the water to the wire and the molecules of the water are under tension, the water can still be drawn away while the cohesive bond between the thin fim of water molecules resists the tendency to part even when other materials are added.
5. The flow within the film of water shown by adding colouring is interesting, but unable to deduce whether there is some gravitational influence from the Earth, moon or even the mass of the station.


Micro gravity is a good tool for allowing us to see how water exists inside the tube here on earth.

This video shows how strong the cohesive bond of a thin film of water really is subjecting it to boiling from a soldering iron and still it does not fail.

How do trees really lift water to their leaves?
Author: Andrew K Fletcher

The arguments for accepted explanations for fluid transport in trees has not been forthcoming, in fact this thread has shown they are indeed flawed.

Ever thought about how Giant Trees towering over a hundred metres can raise water to their leaves without an obvious pumping mechanism?

It may interest you to know that the current explanations are nonsense.

Take root pressure for example. Do roots really squeeze water to the tops of trees? Or Capillary action. Can trees soak up water and release it into the atmosphere like a giant sponge, if this were the case, rising damp would ooze from the tops of walls and even tall buildings? The Oceans would infiltrate the soils and ooze out at a higher level than the ocean.
The Cohesion tension theory as it stands sucks! And relies on water leaving the leaves and this is thought to somehow drag on a chain of water stretching right to the roots. (elaborate way of saying sucks)

Imagine standing on a desk let alone a hundred meters in the air and trying to suck water up a straw from a bottle on the ground. We can't do it so why do we expect a tree to be given different rules? It goes on to say that the huge number of leaves cause a collective pull. Well there are plenty of trees that stand at impressive heights, that are not furnished with a huge canopy of leaves and yet are able to effortlessly draw water from the soil and absorb moisture from the air. The larch being one example. But what about deciduous trees. In the Autumn the leaves fall and yet somehow in the spring the tree picks up where it left off and circulation continues inside causing the buds to form. How does this fit with the leaves having to pull water up? And then Straburger’s experiments where he killed a tree suspended vertically in a bath of picric acid. Strasburger observed circulation continuing for several weeks after the tree was completely killed ruling out living processes.


For those out there that continue to adhere to these quaint proposals for the ascent of sap in tall trees, namely root pressure, the cohesion tension theory, osmosis, capillary action, They are WRONG!

The trees circulate fluids, they do not have a preposterous one way fluid hoist system, but a circulation driven by density changes caused by evaporation altering the sap within the leaves and branches not unlike our own circulation which also benefits from density changes in the fluids again caused by evaporation.

Witsend:

I'm very happy with altrnate theories but why try and improve on osmosis? Surely it explains everything? I'm not sure that ANYTHING need be added to this process. It's just that the roots can take up water and the leaves can give out water. Perfect illustration of the same principle with reversed applications.

Lyner:

The arguments for accepted explanations for fluid transport in trees has not been forthcoming, in fact this thread has shown they are indeed flawed.

AKF. Why are you resurrecting this?

So your argument is not flawed?
As a matter of fact, you have no scientific argument at all. You keep repeating purple passages and the quoting the same instances. Is there any new development in research since you last posted?
We established that, in your smooth tube, you could get a measurable effect from cohesion in water which was a surprise to me. I have accepted that it happened. But is does not explain where the energy comes from.

Your explanation ignores the rest of Science on the grounds that you are ignored due to lack of qualifications. The reason that I / we don't accept your explanation for the phenomenon is because it is not a scientific one. You are hanging it all on the idea of cohesion vs adhesion. However, the Science which applies everywhere else in the World is not allowed to act inside plants - according to you. Isn't Science supposed to be consistent?

Whilst we are 'imagining', lets discuss your circulatory model and use a simple mechanical model.
Take a long loop of rope hanging over a pulley at the top of a building. Tie buckets at regular intervals onto the rope. Fill each bucket with water and add some stones. The stones represent your dissolved salts.
The buckets are spaced equally on the rope, for a start. (This is a simple model, so you have to ignore the problem of getting the buckets over the pulley at the top if the rope moves around - but that could be solved, of course.)

As an analogy to your transport theory, some water and some of the rock leaves the topmost bucket - leaving it half full and with most of the rock in it. It is now lighter than all the other buckets. Manually pull one side of the rope down and half empty the next bucket and the next and the next, as they reach the top and go over. There is now an imbalance. One side of the rope has less load than the other which, left to itself, will pull the emptier buckets back up to the top and those full of water will fall back down. You won't get a circulation.
The only way that you can sustain the motion is for someone at the top to be putting more rocks into the buckets that you want to go down. To lift water constantly, you need fractionally more weight to be added on the other side - constantly.
In a plant, the only source of extra weight, up there with the leaves, is C from the CO2 from the air (during photosynthesis). Just do the sums - compare the mass of water lost during transpiration with the mass of food produced by photosynthesis. There are just not enough 'extra rocks' produced at the top to pull the required amount of water up in the buckets. As I have so often said -The Numbers Count!
I have avoided using the Energy word because you have ignored its use in the past. The above, very mechanical, model shows that your proposed system cannot work. Can you possibly have an argument against what I have written?

Not hanging it on the idea of cohesion versus adhesion, this argument was for the tubular experiments, which of course applies to the density flow theory also. Science is supposed to be consistent but it clearly is not when there are errors in the science!

You appear to be missing a huge chunk of information in your analogy. Let me try to clear it up for you.

Picture a 3 mil bore tube (for instance) as one ascending limb, in this case representing the phloem, which is predominantly downward flowing sap and has far more dissolved solutes in it than the predominantly ascending sap in the xylem vessels. (published science).

Now back to the tubular experiment which admittedly is a simplified model designed only to show the density flow and that cohesion and adhesion play a part in the experiment, although I suspect not an equal part, but let’s ignore this for now.

In our ascending tube we use say 6.5mm bore tubing and do not include any salt for the moment. We raise our unequal bore tube up to say 24 meters and we do not see a flow in either direction but a stagnation of water suspended inside both the 3 mil bore tube and the 6.5 mil bore tube. In fact we could probably show 2 tubes attached to one side and a single tube attached to the other side providing there is a smooth uninterrupted bore at the upper most part of the suspended tube. All ends are open to the atmosphere but suspended in a bottle or bottles filled with water and at equal levels with the ground.

Now, let us see how this fits with your rope and bucket analogy. Ok let’s ignore the buckets and rocks for now. If we had a rope that was the same diameter and the same molecular weight, the rope with careful positioning could indeed stay suspended as there would be an equal counterbalance.

But let’s add a rope twice the size and twice the weight on one side of the pulley. Of course we would see one side pulled down by gravity and the lighter rope side drawn up without any added weights.

In the experiment and inside the tree or plant, there is an equalizing fluid balance that takes away the need for raising the fluids or indeed suspending the fluids.

Unlike the simplified experiment the tree has a multi conduited system inside a larger conduit, the bark with its roots beneath the soil. This is important in this instance because like the bottles of water, it offers support for the columns due to the air soil and water pressure applied to the outside of the tree and more so to the roots.

Yet if we cut the roots off or indeed run a chainsaw through the multiconduited tree system we do not see water oozing out but the water inside retracts up the severed trunk, and this also happens when the ends of the tubes are pulled from the bottles while the water is suspended inside the inverted U tube.

Now back to the flow and return system. According to the above explanation and indeed observations, we can have several upward flowing xylem vessels that are counterbalanced by a ingle downward flowing phloem vessel (for arguments sake) This would give us a mechanism for shedding a huge volume of water at the leaves while returning a smaller yet denser volume down the phloem vessel. Again this experiment was conducted albeit a scaled down version of the Brixham Experiment. “ x ascending salt free and one descending tube attached at the centre which was raised to 2.5 metres. Result was that the flow and return continued to work regardless of the weight on either side of the inverted U tube.

The extra molecular weight at the leaf is not entirely relying on CO2. For example, a deciduous tree that has shed it’s leaves cannot rely on CO2 but somehow manages to circulate fluids to the emerging buds.

You have overlooked the nutrients and colloids from the soil, these are delivered to the leaves in dilute solution and MUST be concentrated by evaporation! Sugars are produced at the leaf from CO2 but cannot be produced if there are no leaves!

Inside the deciduous tree that has shed it’s leaves we have suspended sugars and salts, most of which migrate to the roots during the fall again verifying the need for gravity in any theory that addresses the ascent of sap in tall trees. All that would be required for circulation to continue is an unequal density in the sap and the warmth during the spring and summer provides an external heat / density change to the sap, sufficient to trigger an increase in circulation, but also an increase in positive pressure at the branches, providing the impetus for buds to emerge.

Yes I do have an argument, not against your work an motion analogy but against how you have applied it to a fluid based system.

Andrew

P.S. Yes there has been a huge development recently with regards to publication.

Lyner:
So a few lines of total logic are answered with far too much verbiage to even read, let alone answer.
You have not answered the overwhelming fact that, somewhere, you have to produce an equal WEIGHT of falling water plus stuff (plus a little bit) to balance the amount of water you need to raise. (You would not argue against the idea of vast amounts of water being transpired, I presume) Whether you are discussing 20m or 1cm. Where do all these extra weights - ropes, salts etc. come from way up there in the tree? If you want to pull something up you need something to pull it down with. If you want the process to continue, according to your model, you keep needing extra weight added at the top. Where could it possibly come from? This is not Science - it's what a child with a construction kit would conclude. It could not work on that principle.
Can you really not understand that?

I wonder why I bother, sometimes.

Try the "Bleeping" experiments before you jump to conclusions!

Listen to what has been said!

Lyner:
We frequently find that alternate Science theories just change direction to suit rather than dealing with inconsistencies. If a molecule interacts chemically or mechanically with its neighbours in a particular way under one set of circumstances then, unless conditions are radically changed, we normally expect it to behave the same way in another set.
Just how the molecules are supposed to know they're in a tree and not in a tube beats me. Unless it's supposed to be the 'flow' that sustains the flow - being perpetual motion.