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Giant trees have no trouble pumping water to top branches: new research
- arghandugh 3mo ago[dead]
- nullorempty 3mo ago>Giant trees have no trouble pumping water to top branches Hm, may be because they are not really "pumping" the water?
- leni536 3mo agoWhat would you call it?
- cj 3mo agoNot that it really matters, but the article also refers to it as “drawing water to the top”. That seems more representative of reality than “pumping water from the bottom”.
- margalabargala 3mo agoYeah it's the difference between creating low vs high pressure.
- card_zero 3mo agoThe low pressure is up there already, for free. Or the high pressure is down here, whichever way you want to look at it.
- chowells 3mo agoIf you think of it that way, you have a real problem. It only takes about 10 meters for the weight of a column of water to create enough downward force that it starts vaporizing, at which point no pumping action works. This is why any deep well has a submerged pump. You simply can't pull water upward further than that with negative pressure in the Earth's atmosphere. It must be pushed with positive pressure instead. This is why the question is interesting. You can't just suck water to the top of a 60 meter tree. There must be some kind of positive-pressure pumping involved.
- pulvinar 3mo agoThe trick for trees is capillaries, which change the equation. The 10 meter limit only applies to larger columns. With capillaries there's a high negative tension that allows evaporation from leaves to pull the xylem sap up 100 meters or more. There's no free lunch here. The Sun drives the evaporation, and if the tree were in a closed system with no solar input, the humidity would eventually get high enough to stop it.
- tenuousemphasis 3mo ago>if the tree were in a closed system with no solar input ... that would be the least of the tree's problems.
- deleted 3mo ago[deleted]
- theendisney 3mo agoThis line of reasoning has always cracked me up. The internal dialog acidentally out loud at the least flattering moment. I believe the correct response to be: The tree is a perpetual motion machine hooked up directly to the wheelworks of nature! It PUMPS 500 liters per day usibg Wind, solar, capilar action and evaporation! How do i charge my car with this?
- lazide 3mo agoWell, if you chop it down and burn it to boil water, then Use it to spin up a turbine…
- taneq 3mo agoIt’s like the pop sci fact that if you took all your blood vessels and laid them end to end… you would die.
- hinkley 3mo ago
- gitaarik 3mo ago“Trees contain lots of thin, hollow vessels and they suck water upwards by creating low pressure at the top,” So sucking / pulling?
- IsTom 3mo agoSo a suction pump?
- card_zero 3mo agoSame principle as chimneys. But I also noticed this line: > leaves which have adapted to withstand greater water stress before wilting. That must be one of the "adjustments to water transport" mentioned. So I suggest that they do, in fact, have trouble pumping water to top branches.
- DANmode 3mo agoOr, it’s simply a rate to variably adjust to, so the tree is neither flooding nor parching the leaf.
- gitaarik 3mo agoMaybe it's not more trouble pumping, eh, sucking water up. But that the top branches are the last ones to get water in periods of draught, and have therefore more resilience?
- hinkley 3mo agoMy recollection is that capillary action is a little from column a and a little from column b.
- rolph 3mo agomore like capillary action. https://en.wikipedia.org/wiki/Xylem#Cohesion-tension_theory https://en.wikipedia.org/wiki/Xylem#Cohesion-tension_theory
- card_zero 3mo agoOh, so we don't really know how it works. Fun.
- rolph 3mo agothe research is relevant to the issue of transpiration column hieght as a postulated limitation to overall hieght of any tree. a column of water is pulled by hydrogen bonding between molecules in a tug of war fashion, the top of the column is where water is dissociated from the column at such a rate as to maintain low pressure with respect to the column[xylem] in summary water moves from bottom to top in a transpiration stream, that ultimately ejects water vapour from the leaves, resulting in a low efficiency mechanism, that loses a lot of the water but occurs at such a rate that the low efficiency is "good enough" for whats needed.
- fc417fc802 3mo ago> a transpiration stream, that ultimately ejects water vapour from the leaves I don't believe this is correct, or rather is not a required component of the system but rather incidental. The chemical system within the leaf removes water via chemical reaction. There is a respiration process to dispose of waste gasses. Water vapor happens to be lost to this process not of necessity but rather because keeping it separate is quite difficult (ie requires significant complexity and additional energy expenditure). I expect that many desert adapted species approach perfection (but have not bothered to verify).
- RetroTechie 3mo ago> I expect that many desert adapted species approach perfection (but have not bothered to verify). No they have different strategies to minimize water loss that comes with exhanging CO2 & O2 to the atmosphere. For example: https://en.wikipedia.org/wiki/Crassulacean_acid_metabolism https://en.wikipedia.org/wiki/Crassulacean_acid_metabolism Portulacaria Afra (elephant bush) is a nice example. It can switch between C3 and CAM photosynthesis pathways as needed.
- cwmoore 3mo agoThey do wave in the wind, and evolution is likely capturing some of that motion for work.
- hetspookjee 3mo agoNot sure if you’ve ever visited the groves in California where these huge trees grow but they seem to find the place where the wind doesn’t really seem to bother them, among other reasons (fog staying and little creeks terminating are others). And when the wind comes along it’s surprising how little they actually wave. Such tiny radii change I reckon cannot move much water like you’d need for a pumping notion. So I’d say it has barely if any an influence
- cwmoore 3mo agoI have seen trees before too, anecdotally, my random naysayer.
- cwmoore 3mo agoWatching trees not move much is a low standard for proof—maybe you misunderstood the intent of my comment. If it isn’t upthread, the seminal research on the mechanism (Cohesion Tension Theory) is from 1894: https://www.jstor.org/stable/91804 https://www.jstor.org/stable/91804
- HarHarVeryFunny 3mo agoThere seems to be a lot of things that come together to make it work, but it's basically sucking not pumping. The term to google is Transpiration. It's a bit like a siphon effect with water evaporating from the leaves creating low pressure internally which draws more water up, and the reason it's able to pull a whole column of water up is because water molecules stick together to some extent via hydrogen bonds. Given that evaporation is what is driving it, I wonder how that works with evergreens with low evaporation - I guess it's basically a replacement system, so you only need to pull what you evaporate.
- alldayhaterdude 3mo agoHappy for them.
- lukeholder 3mo agoThis made me laugh out loud. Thanks.
- nomel 3mo agoThis goes against all previous research/measurements for actually tall trees (looks like they only considered up to 80m) and the fact that there are exactly zeros trees in the world taller than 130 meters [1]. Wide capillaries at the base, like stated in the article, don't seem to be related. [1] https://www.sfgate.com/science/article/REDWOODS-How-tall-can-they-grow-2764144.php https://www.sfgate.com/science/article/REDWOODS-How-tall-can...
- fc417fc802 3mo agoI agree it doesn't pass the sniff test (where are the 500 meter trees in the rainforests?) but I think it would make an excellent goal for molecularbiological and genetic engineering. We (our civilization) need to become much more skilled at that before we start editing the human germline, and we will inevitably want to edit the human germline eventually (or rather we are currently exhibiting great restraint in not doing so but I'm not sure how much longer that will last), and anyway thousand meter trees just sound like they would be really cool.
- Sharlin 3mo agoThere are obviously other factors limiting tree growth, like compressive strength.
- fc417fc802 3mo agoWhich would also serve as reasonable challenges for genetic and molecularbiological engineering so ... what's your point? Or do you mean to suggest that the failure of any accepted tree height records to surpass the maximum capillary distance can be explained by some other factor? (Based on your other comment it seems safe to assume that isn't what you meant but anyhow.) That seems far too convenient given that the observed cutoff is within the expected range.
- Sharlin 3mo agoI was referring to your "500m trees" which would be over 3x taller than the tallest trees ever seen.
- m463 3mo agoon the other hand, many giant trees get the water out of the air via fog: Coalescence of coastal fog accounts for a considerable part of the trees' water needs.[23] https://en.wikipedia.org/wiki/Sequoia_sempervirens#Fog_and_flood_adaptations https://en.wikipedia.org/wiki/Sequoia_sempervirens#Fog_and_f... https://en.wikipedia.org/wiki/Sequoia_sempervirens https://en.wikipedia.org/wiki/Sequoia_sempervirens
- nomel 3mo agoSequoia are still limited in height by gravity, probably due to capillary pressures. [1] If they evolved to be segmented, they could probably do it. [1] https://www.sfgate.com/science/article/REDWOODS-How-tall-can-they-grow-2764144.php https://www.sfgate.com/science/article/REDWOODS-How-tall-can...
- efskap 3mo agoSimilarly, it blows my mind that all trees are made of air, specifically the carbon in it. I used to think that the biomass must come from the soil, but reality is more interesting.
- c22 3mo agoKind of like how the vast majority of weight loss in animals happens via exhaling. Weirder still is the realization that all the air is just trapped light.
- kijin 3mo agoActually, all matter is just trapped energy.
- theendisney 3mo agoThere is no such thing as energy.
- lazide 3mo ago
- calibas 3mo agoThe largest tree on record is rejected in part because it's over the theoretical limit: https://en.wikipedia.org/wiki/Nooksack_Giant https://en.wikipedia.org/wiki/Nooksack_Giant Too bad we cut it down, along with almost every other giant Douglas-fir.
- hinkley 3mo agoThere are stories that the moss on trees in temperate rainforests allow the tree to pull water from their branches instead of the ground, increasing their max height. For a while there were people poaching the moss that facilitated this, which is a problem because it grows only inches per year.
- ryanmcbride 3mo agoGod that's sad. We really can't have anything nice.
- hinkley 3mo agoIt’s harder to remove the moss from high up in the tree and there are more risks in doing so. I was never clear on how prevalent this shittery was.
- chasil 3mo agoKurzgesagt has two videos on trees addressing this and other questions. https://m.youtube.com/watch?v=ZSch_NgZpQs https://m.youtube.com/watch?v=ZSch_NgZpQs https://m.youtube.com/watch?v=pHJIhxZEoxg https://m.youtube.com/watch?v=pHJIhxZEoxg
- Minor49er 3mo agoI'd be careful suggesting Kurzgesagt because they push propaganda for large corporations https://www.youtube.com/watch?v=HjHMoNGqQTI https://www.youtube.com/watch?v=HjHMoNGqQTI
- throwuxiytayq 3mo agoIs this confirmed/factual? Their reddit response to the controversy definitely gave me second thoughts
- pkghost 3mo agoFolks still sleeping on structured water. While admittedly contested and only reproduced by a few labs outside Gerald Pollack's at University of Washington, there is a solid case that it could play a role in transporting water and sap to the tops of trees. At least, it's involved in the motion induced in hydrophilic tubes when there is sufficient ambient radiant energy (uv/infrared). Relevant papers: "Exclusion-zone water inside and outside of plant xylem vessels." 2024 Scientific Reports. https://www.nature.com/articles/s41598-024-62983-3 https://www.nature.com/articles/s41598-024-62983-3 "Surface-induced flow: a natural microscopic engine using infrared energy as fuel." 202 Science Advances. https://www.science.org/doi/10.1126/sciadv.aba0941 https://www.science.org/doi/10.1126/sciadv.aba0941 "Long-range forces extending from polymer-gel surfaces." 2003 Phys. Rev. E. https://link.aps.org/doi/10.1103/PhysRevE.68.031408 https://link.aps.org/doi/10.1103/PhysRevE.68.031408 Pollack's site: https://www.pollacklab.org/ https://www.pollacklab.org/ Some critiques of Pollack's theory: Schurr, J.M. (2013). Phenomena associated with gel–water interfaces: analyses and alternatives to the long-range ordered water hypothesis. J. Phys. Chem. B, 117(25), 7653–7674. https://doi.org/10.1021/jp302589y https://doi.org/10.1021/jp302589y Elton, D.C., Spencer, P.D., Riches, J.D. & Williams, E.D. (2020). Exclusion zone phenomena in water — a critical review of experimental findings and theories. Int. J. Mol. Sci., 21(14), 5041. https://doi.org/10.3390/ijms21145041 https://doi.org/10.3390/ijms21145041 (open access; the most thorough critical review) Elton, D.C. & Spencer, P.D. (2021). Pathological water science — four examples and what they have in common. In Water in Biomechanical and Related Systems (Biologically-Inspired Systems, vol. 17), pp. 155–170. Springer. https://doi.org/10.1007/978-3-030-67227-0_8 https://doi.org/10.1007/978-3-030-67227-0_8 (preprint: https://arxiv.org/abs/2010.07287 https://arxiv.org/abs/2010.07287)
- theendisney 3mo agoI regretably didnt save it but there was a truly hilarious topic on usenet sci.physics long long ago. If we've gathered enough evidence against something or if the thing goes against accepted consensus you are forbidden from doing further research and new evidence is no longer allowed. The topic then invited others to list such topics. The list grew to hundreds of entries and people couldnt resist getting angry reading their personal trigger words despite there being many more silly things on it. Yours shall be filed under homeopathy :)
- jzer0cool 3mo agoAny truth to whether water pumped by tree (branches) is potable?
- karim79 3mo agoI grow marijuana and chillies from time to time. I got good at it. I will say that plants are malleable in untold ways and so I find this article to be unsurprising. Plants will do what they need to do in the end. I've done stuff like co2 bombing, and increasing nutrients to the point to where I get a whole new ecosystem of insects and an entirely new situation. It is such fascinating stuff that it's actually the life I want to live. I'm a computer scientist but now I yearn for the botanical sciences. I highly recommend checking out defoliation strategies and low-stress training methods for anyone interested. Plants are not dumb creatures. The results you can get from them are astonishing and the science of what plants actually are becomes more profound by the day.
- aaron695 3mo ago[dead]
- card_zero 3mo agoThere is apparently such a thing as "Computational Botany", where you model virtual plants.
- BobaFloutist 3mo agoI suppose that would make "Botanical Computation" the use of plants to perform calculations.
- mountainriver 3mo agoWith a lot of software getting eaten up I’m increasingly interested in biology. Seems like one of the later frontiers that could have massive benefits, and AI is really well suited to help us understand it.
- karim79 3mo agoTrue and also, the actual physical contact and results are absolute magic. Maybe we need to create a "computer scientists for botony" forum. I think that has legs. Botany is great because the results are basically what I'd call magic. It's such beauty (and horror on occasion). The marriage of CS and botany seems like a match made in heaven and just from writing these comments I've convinced myself that it's probably the most practical way to go forward in life.
- luxuryballs 3mo agoI’m glad to find the trees are doing well, even the big ones, that managed to grow big... ???
- cwmoore 3mo ago“The root cause is nailed down (not a theory anymore)…” —Claude
- pinchydev 3mo ago[dead]
- accidentallfact 3mo agoI don't get why it is believed that trees can't pump water above a certain limit, all it should take is a system of valves, something that plants already have for other purposes. It certainly isn't lumuted by trees literally sucking water up as that would limit them to a height that can be easily exceeded by the majority of trees. It seems that trees just don't grow that tall anymore. Even common trees such as the spruce seem to be able to reach 100m, they just kind of don't. One possibility is the depletion of nutrients. But what I think is to blame is the lack of elephants. They constantly ruined young trees and the lucky few that survived then grew huge. Perhaps the redwoods were actually created by the natives, who removed young trees, and kept the old trees standing.
- tryagainian 3mo agoAlso, wasn’t the 250 ppm atmospheric CO2 concentration prior to the start of the Industrial Revolution a historic low as far a geological-time goes? I suppose that’s not particularly relevant for more recent old growth tall trees that seem to have got by fine in a colder Earth. But it’s easy to imagine a warmer, wetter, Earth with higher atmospheric CO2 concentrations being more conducive to taller tree growth. On the other hand, I probably don’t really know what I’m talking about, not my area of expertise.
- bnegreve 3mo ago> all it should take is a system of valves, That would work, but it's not how to works apparently. According to this veritasium video, it's because of "negative pressure" aka tension. https://www.youtube.com/watch?v=BickMFHAZR0 https://www.youtube.com/watch?v=BickMFHAZR0 I recommend watching, I think it's one of the best veritasium Dereck has ever produced.
- huijzer 3mo agoAnother paper for the “Obviously” category. Otherwise the leafs at the top would be brown. But I did a PhD myself and our papers were exactly the same. Noone wants to rock the boat. Professors just want to get to their pension without problems. And people will cite things that are in line with their own stuff. So there you have it. Just proving the obvious time and time and time again.
- kank0de 3mo agoplants are very brave, both metaphorically and physically.
- yubblegum 3mo agoRather tenacious and unrelenting than brave. Many of them wear war paint, employ chemical warfare, and dress up in scary getups to scare away potential enemies/predators. Effective for sure, but "brave"?
- stymaar 3mo ago> These vessels have evolved intricate adaptations that can maintain the water in liquid form, even under the extreme low pressures This sentence undersells the phenomenon quite a bit: the “extreme low pressure” is in fact several bars of negative pressure and the challenge of maintaining water in liquid form is avoiding cavitation. I was exposed to the physics of trees though the entrance exam to École Polytechnique (France's best University) and it's been carved in my mind since then: http://alainrobichon.free.fr/Concours/X_PC_PH1_01.pdf http://alainrobichon.free.fr/Concours/X_PC_PH1_01.pdf AFAIK students are still being given this masterpiece for practice even though it's now 25 years old.
- Arodex 3mo ago... May we have the solution to the questions, also? I went through the concours too but I am very rusty. See also Veritasium on that topic: https://youtu.be/BickMFHAZR0 https://youtu.be/BickMFHAZR0
- kazinator 3mo agoI would not even expect there to be a problem; it only seems that way if you naively imagine that trees contain continuous, open pipes from top top bottom. A bucket brigade works just as well up ten flights of stairs as up one hundred. So does a system of opening and closing valves. We can pump water from a bucket on one floor of building to a bucket on the next floor easily. Then we can repeat the same thing at the next floor; the pressure from the numerous floors above doesn't factor in because there isn't a connected water column.