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#1
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how do water move up in tree? what is driving force?
Andrew K Fletcher wrote: Basic theory behind the experiment which caused water to flow 24 metres up a cliff in Brixham, Devon. http://www3.sympatico.ca/slavek.krep...cienceRevw.htm [Hemet] Hi Andrew :-) You have the honor of being a true scientist and experimentalist. Yet you have to answer for some big questions. I agree with Hemet that the theory is not correct. One other thing that it does not explain is how plants have CONTROL over water pumping. Wilting and restoration can be stimulated electrically! I think there are a few hints to this long-time question, but I have never done enough work to generate a bone fide theory about it. Basically I believe that somehow water pumping in plants is an electrical phenomena. (See some of the great work by Prof Bose in his old book) My idea is that there is a REQUIREMENT that sap contain dissolved chemicals because pure distilled water would not be conductive enough nor polar enough to be electrically pumped. If you examine Xylems (tubes through which sap rises) you find very interesting structures. There are cell membranes that exist between a spiral thread of cellulose (insulator) creating a spiral membrane rising up the tube. I suggest (but have not established) that an action potential may travel this membrane such that it creates a pumping action for the fluid in the tube. This action would be similar to the action found in nerves in animals but has a pumping function in plants. Such would explain Bose's electrical reversal of wilting. Also it is already known that tall plants have valves in the xylems which usually do not require sap to be pumped more than a few feet. Just some "new theory" food for thought! Benj |
#2
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how do water move up in tree? what is driving force?
"Benj" wrote in message ups.com... Andrew K Fletcher wrote: Basic theory behind the experiment which caused water to flow 24 metres up a cliff in Brixham, Devon. http://www3.sympatico.ca/slavek.krep...cienceRevw.htm [Hemet] Hi Andrew :-) You have the honor of being a true scientist and experimentalist. Yet you have to answer for some big questions. I agree with Hemet that the theory is not correct. One other thing that it does not explain is how plants have CONTROL over water pumping. Wilting and restoration can be stimulated electrically! To disagree with this theory is to suggest a mechanism for evaporation that does not have any effect on the density of residual fluids inside the tree. Please elaborate as I find this impossible to understand. If we can agree on density changes due to evaporationin transpiring leaves then the rest of the theory is correct also. Andrew Hemet also asked me to answer Strasburger's results, Which I have done, and will add after you have addressed this question at hand. I think there are a few hints to this long-time question, but I have never done enough work to generate a bone fide theory about it. Basically I believe that somehow water pumping in plants is an electrical phenomena. (See some of the great work by Prof Bose in his old book) My idea is that there is a REQUIREMENT that sap contain dissolved chemicals because pure distilled water would not be conductive enough nor polar enough to be electrically pumped. If you examine Xylems (tubes through which sap rises) you find very interesting structures. There are cell membranes that exist between a spiral thread of cellulose (insulator) creating a spiral membrane rising up the tube. I suggest (but have not established) that an action potential may travel this membrane such that it creates a pumping action for the fluid in the tube. This action would be similar to the action found in nerves in animals but has a pumping function in plants. Such would explain Bose's electrical reversal of wilting. Also it is already known that tall plants have valves in the xylems which usually do not require sap to be pumped more than a few feet. Just some "new theory" food for thought! Benj |
#3
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how do water move up in tree? what is driving force?
Andrew K Fletcher wrote: To disagree with this theory is to suggest a mechanism for evaporation that does not have any effect on the density of residual fluids inside the tree. Please elaborate as I find this impossible to understand. If we can agree on density changes due to evaporation in transpiring leaves then the rest of the theory is correct also. Yes. That is a very interesting point. What I suggested implies that the chemicals in the sap are transported up the tree by the "pumping mechanism" which clearly raises the question of why does not the materials in the sap concentrate at the top of the tree as water evaporates from the leaves? Good point. I'm not sure what the answer is! Clearly most plants have various chemicals of various kinds in the sap. I do not believe there is any evidence that pure water is pumped up plant stems. I'm not sure what kind of "pumping mechanism" would pump just the water leaving the chemicals in place. I do presume that a tree for example has a much larger area (volume) for storing liquid at the leaves and perhaps processes in the leaves somehow use the chemicals transported in the sap. But this is all speculation on my part. I'm not an expert in plant physiology. |
#4
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how do water move up in tree? what is driving force?
On Sep 3, 3:38 am, "Andrew K Fletcher"
wrote: "Benj" wrote in message ups.com... Andrew K Fletcher wrote: Basic theory behind the experiment which caused water to flow 24 metres up a cliff in Brixham, Devon. http://www3.sympatico.ca/slavek.krep...cienceRevw.htm [Hemet] Hi Andrew :-) You have the honor of being a true scientist and experimentalist. Yet you have to answer for some big questions. I agree with Hemet that the theory is not correct. One other thing that it does not explain is how plants have CONTROL over water pumping. Wilting and restoration can be stimulated electrically! How do you do this? Sounds like it has great prank potential. |
#5
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Here I want to explain that how giant redwoods hoist water up and although I know this is not exactly one but here we can understand real concept behind
how do water move up in tree ? just click following link: www.wonderquest.com/Redwood.htm
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