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> The researchers found that the effect varied with color and peaked at a particular wavelength of green light. I wonder if this affects photosynthesis in any
by montjoy 3y ago
> The researchers found that the effect varied with color and peaked at a particular wavelength of green light.
I wonder if this affects photosynthesis in any way? IIRC plants are green because chlorophyll does not absorb that color. Maybe that’s partially because green light induces too much evaporation?
- canadianfella 3y agoI’ve always wondered why inefficient green is the way plants evolved. Interesting question.
- genewitch 3y ago[green] plants are damaged by green light, is the way i've heard it explained. So they "block it".
- malfist 3y agoMaybe, 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 agoI 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 agoThat’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 agoAt its simplest, reflecting green light would send the light through the water twice instead of once. Neat trick, plants.
- bdd8f1df777b 3y agoWell, the chloroplast was evolved when all life forms were submerged in the sea
- jacquesm 3y agoThe sea is on the other side of a very carefully policed barrier.
- montjoy 3y agoNo doubt. I’m just toying with the idea of how this might impact our understanding of how plants work.
- MagicMoonlight 3y agoThat’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 agoIt 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 agoPlants 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 agoThat'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 agoWatch Veritasium’s awesome video on this
- _nalply 3y agohttps://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.
- deleted 3y ago[deleted]
- luxuryballs 3y agoor the opposite, it likes the green light because reflecting it keeps the plant cool? I also recall a study where trees emitted a sort of mist into the air, perhaps the greenery helps with that process too
- darig 3y ago[dead]
- austin-cheney 3y agoNo. Plants reflect green to balance luminosity extremes. Green is by far the most luminous color in the visible spectrum with dark purple being the least luminous. Plants that reflect purple absorb the most visible light and can produce the most sugars. Most plants must undergo a chemical transition to shift from production to dark mode and by choosing to reflect green maximum energy production is sacrificed for internal chemical stability.
- cbcivyxt 3y ago[dead]
- kalium-xyz 3y agoWhats the mechanism here?
- austin-cheney 3y agoI found this which seemed informative: http://www.esalq.usp.br/lepse/imgs/conteudo_thumb/Why-did-chlorophyl-evolve-to-be-green-as-opposed-to-black.pdf http://www.esalq.usp.br/lepse/imgs/conteudo_thumb/Why-did-ch...
- bhewes 3y agoC02 levels. We use C02 to turn our weed buds purple.
- _nalply 3y ago> most luminous color What does luminous mean exactly in this context? I know that our eyes are most sensitive to green. For example a green LED needs less power to seem as bright as a red LED. But our eyes don't matter in this subject. So I am scratching my head about what you mean that green is the most luminous color?
- MayeulC 3y agoI think this is the color (wavelength) that corresponds to the sun's emissivity peak (irradiance in W/m²). The fact that our eyes are most sensitive to green is probably not an accident, but is it due to the color of leaves, or is it due to sunlight?