3 ms·

Maybe, but evaporation is critical for plants. They don't have a heart to pump blood and supply nutrients, they have to rely on evaporation to move nutrients fr

Maybe, but evaporation is critical for plants. They don't have a heart to pump blood and supply nutrients, they have to rely on evaporation to move nutrients from the roots up

chimpanzee 3y ago
I imagine the leaves being green would encourage this evaporation. The upper layers of cells are probably effectively translucent and might be awash in green light, perhaps increasing the rate of evaporation and improving overall transpiration.
- xigency 3y ago
  That’s my guess as well. The green chlorophyll is inside of the cell. It absorbs sunlight for food but reflects the green light back through the water-air boundary. Perhaps the effect on evaporation or water movement provides a better benefit for the plant than absorbing the energy of that spectra. For instance, by increasing the efficiency of respiration.
  - deanputney 3y ago
    At its simplest, reflecting green light would send the light through the water twice instead of once. Neat trick, plants.
bdd8f1df777b 3y ago
Well, the chloroplast was evolved when all life forms were submerged in the sea
- jacquesm 3y ago
  The sea is on the other side of a very carefully policed barrier.
  - geysersam 3y ago
    Still, it's less of a challenge to pump water from your roots if you're in the sea. Did the earliest green plants even have roots?
    - eru 3y ago
      > Did the earliest green plants even have roots? No. Not even all land plants have roots.
montjoy 3y ago
No doubt. I’m just toying with the idea of how this might impact our understanding of how plants work.
MagicMoonlight 3y ago
That’s a good point actually. I never thought about the fact that a tree is evaporating 100L a day without any heat. They must have figured this out.
- yetihehe 3y ago
  It still uses heat. Evaporation actually helps plants keep cool by using up the heat from sun that would otherwise heat the plant too much.
SkyPuncher 3y ago
Plants rely on on capillary action to bring water up: https://www.usgs.gov/special-topics/water-science-school/science/capillary-action-and-water#:~:text=the%20plant%20tissue.-,Capillary%20action%20helps%20bring%20water%20up%20into%20the%20roots.,water%20to%20the%20furthest%20leaf https://www.usgs.gov/special-topics/water-science-school/sci.... There's probably some aspect of evaporation, but the density of water is much, much higher when it's kept in liquid form.
- mechanicalpulse 3y ago
  That's part of the process, but not all of it. The overall process of water movement through vascular tissue is called transpiration [0]. Yes, capillary action plays a part, but the underlying process is due to differences in water potential. To avoid saturation (which would halt the flow of nutrients), water is released through pores in the leaves called stomata [1], where it evaporates, creating a differential that results in additional water being pulled in from the soil. [0] transpiration: https://en.wikipedia.org/wiki/Transpiration https://en.wikipedia.org/wiki/Transpiration [1] stoma: https://en.wikipedia.org/wiki/Stoma https://en.wikipedia.org/wiki/Stoma Disclaimer: I'm not a biologist. I'm a third-generation home gardener; my grandfather was the youngest of his family and the to leave the family farm in Kansas to go to college. He always maintained a large garden and loved sharing his knowledge along with his vegetables. Edit: added links and a disclaimer
- iamgopal 3y ago
  Watch Veritasium’s awesome video on this
  - _nalply 3y ago
    https://www.youtube.com/watch?v=BickMFHAZR0 https://www.youtube.com/watch?v=BickMFHAZR0 It's an old video, more than ten years ago, but it aged well IMHO. I re-watched it and re-learned things I have forgotten.

Maybe, but evaporation is critical for plants. They don't have a heart to pump blood and supply nutrients, they have to rely on evaporation to move nutrients from the roots up

chimpanzee 3y ago

I imagine the leaves being green would encourage this evaporation. The upper layers of cells are probably effectively translucent and might be awash in green light, perhaps increasing the rate of evaporation and improving overall transpiration.

xigency 3y ago
That’s my guess as well. The green chlorophyll is inside of the cell. It absorbs sunlight for food but reflects the green light back through the water-air boundary. Perhaps the effect on evaporation or water movement provides a better benefit for the plant than absorbing the energy of that spectra. For instance, by increasing the efficiency of respiration.
- deanputney 3y ago
  At its simplest, reflecting green light would send the light through the water twice instead of once. Neat trick, plants.

bdd8f1df777b 3y ago

Well, the chloroplast was evolved when all life forms were submerged in the sea

jacquesm 3y ago
The sea is on the other side of a very carefully policed barrier.
- geysersam 3y ago
  Still, it's less of a challenge to pump water from your roots if you're in the sea. Did the earliest green plants even have roots?
  - eru 3y ago
    > Did the earliest green plants even have roots? No. Not even all land plants have roots.

montjoy 3y ago

No doubt. I’m just toying with the idea of how this might impact our understanding of how plants work.

MagicMoonlight 3y ago

That’s a good point actually. I never thought about the fact that a tree is evaporating 100L a day without any heat. They must have figured this out.

yetihehe 3y ago
It still uses heat. Evaporation actually helps plants keep cool by using up the heat from sun that would otherwise heat the plant too much.

SkyPuncher 3y ago

Plants rely on on capillary action to bring water up: https://www.usgs.gov/special-topics/water-science-school/science/capillary-action-and-water#:~:text=the%20plant%20tissue.-,Capillary%20action%20helps%20bring%20water%20up%20into%20the%20roots.,water%20to%20the%20furthest%20leaf https://www.usgs.gov/special-topics/water-science-school/sci.... There's probably some aspect of evaporation, but the density of water is much, much higher when it's kept in liquid form.

mechanicalpulse 3y ago
That's part of the process, but not all of it. The overall process of water movement through vascular tissue is called transpiration [0]. Yes, capillary action plays a part, but the underlying process is due to differences in water potential. To avoid saturation (which would halt the flow of nutrients), water is released through pores in the leaves called stomata [1], where it evaporates, creating a differential that results in additional water being pulled in from the soil. [0] transpiration: https://en.wikipedia.org/wiki/Transpiration https://en.wikipedia.org/wiki/Transpiration [1] stoma: https://en.wikipedia.org/wiki/Stoma https://en.wikipedia.org/wiki/Stoma Disclaimer: I'm not a biologist. I'm a third-generation home gardener; my grandfather was the youngest of his family and the to leave the family farm in Kansas to go to college. He always maintained a large garden and loved sharing his knowledge along with his vegetables. Edit: added links and a disclaimer
iamgopal 3y ago
Watch Veritasium’s awesome video on this
- _nalply 3y ago
  https://www.youtube.com/watch?v=BickMFHAZR0 https://www.youtube.com/watch?v=BickMFHAZR0 It's an old video, more than ten years ago, but it aged well IMHO. I re-watched it and re-learned things I have forgotten.