Tom,
That's interesting stuff!! "Feed me, Seymour!" :shock:
if red need more light, why are cactus and desert plants all green and why are tropical rainforest plants deep in the jungle red?
Desert plants are green because ChloroPhil (hahaha) is more efficient. They've got other adaptations, like photosynthetic trunks or needles rather than leaves (generally). Why aren't all tropical plants red?
Understory plants/autotrophs in any super dense/highly filtered ecosystem, be it a rainforest or 200' under water will have high percentages of red pigments. Only the highest energy light (blue to ultraviolet on down) is able to penetrate to those depths. Since red pigments are the most efficient at capturing that higher energy radiation the plants will produce more red than anything else. That's not to say that others aren't produced as well on the off chance that a large tree might fall and create an extra light situation. I've got a lot of Begonia species in the conservatory at school with green tops and red bottoms to capture the greatest spectrum possible.
That's counter to the entire notion of red needs more light.
Few emergent plants are red, red plants that grow out of the water become green.
True enough. However, with the increase in the red spectra once out of the filtering/reflective capacity of the water the plants are better able to utilize the lower energy end of the spectrum and start producing Chlorophyll in amounts able to mask the Carotenoids.
It takes a lot of N to produce Chl, not much to make red which will catch lots of light and make the Chl a more efficient and the plants can have far less N per unit of leaf area.
If the red pigments are so useful why aren't they the dominant pigment?
I've got no argument with you there, the combination of pigments is most effective.
There are many things a plant can do to get more light or reduce the amount of light.
I wasn't trying to suggest that the plant is attempting to reduce the amount of light, rather, they build more red pigments to capture the increased blue light and so harness the higher energy radiation rather than let it affect their physiology.
I do not buy that red plants need more light nor iron. Never have.
I would argue that plants with higher percentages of caretoids to chlorophyll will need more light simply because of the decreased ability of the carotenoids to capture and utilize the light.
Even so, I still believe that Nitrogen deficiency is the main cause of red coloration in plants. I've had some pretty green "red" plants under some pretty strong light in some well supplimented aquariums.
Best,
Phil
That's interesting stuff!! "Feed me, Seymour!" :shock:
if red need more light, why are cactus and desert plants all green and why are tropical rainforest plants deep in the jungle red?
Desert plants are green because ChloroPhil (hahaha) is more efficient. They've got other adaptations, like photosynthetic trunks or needles rather than leaves (generally). Why aren't all tropical plants red?
Understory plants/autotrophs in any super dense/highly filtered ecosystem, be it a rainforest or 200' under water will have high percentages of red pigments. Only the highest energy light (blue to ultraviolet on down) is able to penetrate to those depths. Since red pigments are the most efficient at capturing that higher energy radiation the plants will produce more red than anything else. That's not to say that others aren't produced as well on the off chance that a large tree might fall and create an extra light situation. I've got a lot of Begonia species in the conservatory at school with green tops and red bottoms to capture the greatest spectrum possible.
That's counter to the entire notion of red needs more light.
Few emergent plants are red, red plants that grow out of the water become green.
True enough. However, with the increase in the red spectra once out of the filtering/reflective capacity of the water the plants are better able to utilize the lower energy end of the spectrum and start producing Chlorophyll in amounts able to mask the Carotenoids.
It takes a lot of N to produce Chl, not much to make red which will catch lots of light and make the Chl a more efficient and the plants can have far less N per unit of leaf area.
If the red pigments are so useful why aren't they the dominant pigment?
I've got no argument with you there, the combination of pigments is most effective.There are many things a plant can do to get more light or reduce the amount of light.
I wasn't trying to suggest that the plant is attempting to reduce the amount of light, rather, they build more red pigments to capture the increased blue light and so harness the higher energy radiation rather than let it affect their physiology.
I do not buy that red plants need more light nor iron. Never have.
I would argue that plants with higher percentages of caretoids to chlorophyll will need more light simply because of the decreased ability of the carotenoids to capture and utilize the light.
Even so, I still believe that Nitrogen deficiency is the main cause of red coloration in plants. I've had some pretty green "red" plants under some pretty strong light in some well supplimented aquariums.
Best,
Phil
