Effects of extended photosynthesis?

[Ekka]

Hi all

I'm doing some research on the effects of extended photo periods. Some trees at a large intersection pretty much dont get relief from lighting.

Once it gets dark on come a blaze of street lights. What do you think the effects would be on the trees? What symptoms would you be looking for? And what solutions do you offer?

 

[ROLLACOSTA]

www.aie.org.uk this site may have some info

 

[texasnative]

What is the natural photoperiod in Brisbane on the longest day of the year, and what is it on the shortest day of the year? One possibility could be a reduction in seed production as many trees rely on a change in the photoperiod to tell them when to flower. I would think that it would have to be a very intensely lit intersection to create much of an interference. As for photosynthesis, depending on the natural photoperiod, there is a point at which any additional light will not benifit the tree. Something else to think about, the foliage must open its stomata to exchange atmospheric CO2 and O2, and this is usually done at night to minimize H2O loss.

 

[NYCHA FORESTER]

I don't believe street lights are a full spectrum light. It may be bright to you and me but to the tree I think it is minimal. (I think I can hear a can of worms being opened)

 

[texasnative]

Street lights are in fact full spectrum lights, however one color of the spectrum is dominant over others, depending on whether it is a high pressure sodium light (the yellow ones-most common), mercury vapor (most common blue light), or metal halide (least common blue HID light for street lighting). I have used all three lights in horticultural applications (winter tomatoes and peppers, mostly). I would agree that the effect on trees would be minimal, however. JMHO.

 

[NYCHA FORESTER]

Wow....... thanks for the heads up (texasnative). Ya learn something new every day. Sounds like it could make for a nice little thesis.

 

[Ekka]

Something else to think about, the foliage must open its stomata to exchange atmospheric CO2 and O2, and this is usually done at night to minimize H2O loss.

I thought light stimulated stomata opening for photosynthesis. This is what I found. What do you think?

Extended photo periods from street lighting cause greater susceptibility to air and water pollution as stomatal pores in leaves remain open longer.

 

[Jim1NZ]

I thought having street lights on trees was not the best because...
During the day the stomata is open through photosynthesis, at night a tree, like humans, has to have a rest period. During this period, there is no photosynthesis so the tree concentrates on defense and repair rather than capturing light.

I know alot of water is lost through the open stomata while photosynthesizing during the day. So if the stomata is open all the time the tree is loosing water very quickly, not efficient!

Any thoughts?

 

[KentuckySawyer]

I have used all three lights in horticultural applications (winter tomatoes and peppers, mostly).


Mostly.

 

[Jim1NZ]

hahaha

 

[Tom D. Wilson]

i thought one of the biggest problem of prolonged photosynthesis would be the amount of water the plant uses in transporation - could make them more susceptable to drought maybe?? its a bit of guess really but plants use most of the water they draw up in the process of photsynthesis dont they??