
Why trees can't grow taller than around 100 metres - drucken
http://www.newscientist.com/article/mg21729004.800-why-trees-cant-grow-taller-than-100-metres.html
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Someone
In contrast, <http://news.ycombinator.com/item?id=5083564> describes a 2004
study that gives 130m as the limit, and claims a world record of 125m. Also,
<http://en.wikipedia.org/wiki/Hyperion_(tree)> is 115m.

However, this theory is less observational; that, IMO, makes it a better one,
even if the maximum height it predicts is of by 10% or so.

In fact, that is fairly typical for scaling laws. For example, bumblebees and
swans are outliers in the field of flying insects, respectively flying birds.
That is why, in those circles, a standard joke is that bumblebees cannot fly,
and swans can fly, but cannot take off from the ground.

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dspeyer
Iirc albatrosses actually can't take off from the ground. They need to jump
off a cliff with an updraft. So they're very careful about where they land.

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quotemstr
> Iirc albatrosses actually can't take off from the ground

Of course they can.

<https://www.youtube.com/watch?v=gKTfcs6LL6A>

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dspeyer
Hmm...

Having now gone back and researched that a little better, it's only Waved
Albatrosses I was thinking of and sources seem to disagree on whether they can
take off from flat ground or not. They certainly prefer a cliff, and will make
a long walk to get to one if necessary.

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vacri
This is an interesting video with an alternate explanation - the pressure
required to get water to the top of the tree. Normally you can only suck a
water column up 10 meters, and that's using a perfect vacuum - but trees can
grow higher than that. The secret sauce is that in a liquid rather than a gas,
you can have a negative pressure.

<http://www.youtube.com/watch?v=BickMFHAZR0>

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stevep98
So, how long until someone engineers some 'helper pumps' to assist trees in
pumping nutrients around. Be nice to see some 1000-foot trees in manhattan to
crowd out some skyscrapers.

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solox3
>>Sugars accelerate as they move

That's no way to describe the diffusion gradient.

Also, this paper does not cover all of Plantae, so for all we know, other
Embryophytes may be limited in height by an entirely different factor.

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pvaldes
The creatures that we call trees, and the Earth had experimented with a lot of
different types of trees, are in fact much higher if we count the roots.

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freiheit
Yes, but the tallest trees (California redwood) have shallow root systems (a
couple meters). Are there trees commonly over 100 meters counting the roots?

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aroman
I remember learning this in my high school biology class a few years ago. I
recall the limit as being 120 meters because of the force of gravity.

Xylum and phloem... memories.

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yukoncornelius
Gravity and cohesion-tension theory.

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monochromatic
This doesn't seem to preclude a tree that's taller than that, but simply an
outlier in its leaf size. Unless I'm misunderstanding something...

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maxerickson
The New Scientist article isn't very clear. The paper proposes that tall trees
are unable to gain energy from leaves above a certain length (my not great
understanding is that a larger leaf can generally move more energy than a
shorter leaf, but a longer stem can only move so much, limiting the useful
leaf size).

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amoxibos
This is why I love HN - the fact that this kind of post can make it to the
front page.

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loceng
It's pretty rare..

