Discussion summary
Recent research confirms that giant trees can efficiently pump water to their top branches. The discussion includes reactions to the findings and questions about tree physiology.
What the discussion says
- Some commenters express amusement and support for the research.
- Others note that the findings seem obvious or question the methodology.
- A few discuss the biological mechanisms and implications for plant science.
“Another paper for the “Obviously” category.”
“The root cause is nailed down (not a theory anymore).”
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- Hacker News
- on 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_f...
by m463 - I 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.
by kazinator - >Giant trees have no trouble pumping water to top branches
Hm, may be because they are not really "pumping" the water?
by nullorempty - The largest tree on record is rejected in part because it's over the theoretical limit: https://en.wikipedia.org/wiki/Nooksack_Giant
Too bad we cut it down, along with almost every other giant Douglas-fir.
by calibas - Kurzgesagt has two videos on trees addressing this and other questions.by chasil
- This 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...
by nomel - > 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
AFAIK students are still being given this masterpiece for practice even though it's now 25 years old.
by stymaar - I 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.
by karim79