Plant reaction from high light to low light.

[Soilwork]

I was just thinking about light compensation points and I read a comment that said 'if a plant is growing it is receiving light above its light compensation point'.

I was just wondering that if a plant went from high light/high co2 to low light/high co2 and the plant had lots of mass, if the plants rate of photosynthesis and nutrient uptake was slowed, what would happen to its existing mass? Would it now be able to support what is had previously grown in high light conditions in a new lower light environment

 

[dw1305]

Hi all,

Would it now be able to support what is had previously grown in high light conditions in a new lower light environment

No, it wouldn't.

Most plants can shed leaves that don't receive enough light to reach LCP, but plants that naturally grow in high nutrient, high light situations may just wither and die.

This is the problem with trying to over-winter some floating plants from tropical environments, they don't have any ability to withstand lower light conditions. If you have a look at the <"Ludwigia sedoides"> thread, this is a plant in that category.

Other plants show plasticity of growth form, for example the leaf rosette in Pistia stratiotes declines to a small, flat rosette under lower light.

I've got plants which have cycled from upright large rosette to flat rosette to upright rosette over a summer - winter - summer sequence.

cheers Darrel

 

[Soilwork]

Thanks Darrel

So the plant would not be able to shed leaves until it achieves a new balance? Interesting. It did always puzzle me this though. I guess it's like feeding a fully grown dog 3 cans of pedigree a day then switching back to puppy food? You would expect the dog to wither. This perhaps explain why a large Amazon sword would melt away in a new low light tank?

 

[dw1305]

Hi all,

So the plant would not be able to shed leaves until it achieves a new balance?

It is going to depend on the plant, my suspicion would be that most "easy" plants can adjust their growth rates, and that a lot of the less easy ones can't. I think plants with floating leaves from tropical regions are probably going to be the ones that are least likely to be able to accommodate to lower light levels, purely because they are always going to be growing in very intense light and aren't CO2 limited.

cheers Darrel

 

[Soilwork]

Makes sense. Thanks