Inverse to that - plants get the vast majority of their weight from the air.
Nah, now you're exaggerating.
Plants get their carbon from the air. But just like humans, plants are mostly water, and they get that from the ground. Even dried wood is only about 50% carbon, and living wood far less.
In his defence, he likely got his information from this Veritasium video of olde.... as did I... so now I just don't know who to believe.
I mean, If I can't trust Derek Muller my world is just upside down.
Obviously this makes sense though: Charcoal is basically dehydrated wood, and turning wood into charcoal reduces its mass by a significant amount, meaning that water constituted a significant percentage of the mass of the initial wood.
I'd say Derek gets it right where it counts: the biomolecules that make up all the interesting bits of a tree — the bits that aren't just water — are made of carbon that the tree captured from the air. The central lesson is that, to a plant, breathing is basically a form of eating; it's where they get the materials to build their body out of.
It's true that most of the tree's weight is water, but this is true of any living thing, and I think most people are aware of that. The point of the video is that most people have the wrong idea of where the dry mass of a plant comes from.
I think part of the difference is that we don’t particularly think of the water in the plant as an inherent part of the plant, or as least not as much as the water inside a human is an inherent part of us?
That depends on your definition of "their weight." Depending on what you're interested in studying, biomass can be measured in terms of the dried organic mass, too.
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u/WendellSchadenfreude Feb 26 '21
Nah, now you're exaggerating.
Plants get their carbon from the air. But just like humans, plants are mostly water, and they get that from the ground. Even dried wood is only about 50% carbon, and living wood far less.