do trees need rest?

[(WLL)]

are trees affected when bright lights shine all night?

 

[gremlin]

good question. im sure someone will come along shortly with an answer

 

[Slvrmple72]

The light would have to be full spectrum and considerably bright to have an impact on the growth cycle of the tree. As far as a tree resting that would be during winter. Please excuse me now as I need to get my rest!

 

[(WLL)]

The light would have to be full spectrum and considerably bright to have an impact on the growth cycle of the tree. As far as a tree resting that would be during winter. Please excuse me now as I need to get my rest!

i dont think trees need the full color spectrum. many plants only need two colors to grow. i could be way off and am very uninformed on this subject.

 

[tree_beard]

ive wondered this myself...

and concluded... not really.

streetlights (at least here in the u.k) are all high pressure sodium lights... the same lights used to grow vegetables and plants indoors. giving a good sprectrum of red and blue light suitable for both vegative and flowering growing cycles.

the effective range of these lights diminishes exponentially, so only give a good (for growing plants) dose of light up to a few yards from the source...

for ages i took notice of any trees and shrubs growing directly under and around street lights... and have seen no noticable differences in trees exposed to artificial light... in theory im sure there should be, but i cant say ive ever noticed any in practice


thats just what i have concluded (ive been known to be dead wrong)

 

[John Paul Sanborn]

are trees affected when bright lights shine all night?

Yes, there are studies that show urban trees near streetlights do get stressed.

Part of the the cycle of trees has them putting out O2 during the dark cycle.

There is more to it (and more even those with a better understanding do not understand) but I lack time, maybe Guy M. will have be able to better state it.

 

[user 23728]

Angiosperms take their cues to flower from vernalization (temperature) or photoperiodism (light).

Plants that exhibit photoperiodism are one of either long day or short day. Now, here's where it gets confusing, it's not the day length that's actually important but the length of night.

So, a long day plant requires less than a specific hours of night. These are usually plants that flower in the spring or summer. Short day plants require more than a specific amount of night to begin flowering. Short day plants can be inhibited from flowering if they experience flashes or sustained light.

Photoperiod plants use a light receptive chemical called phytochrome. Phytochrome is sensitive to the red and far-red region of the visible light specrtrum. So, red and far-red light can effect certain plants, disrupting their circadian rythm, or daily cycle.

I hope this helps.

 

[pdqdl]

Darn good answer for your first post! We will look to hear more from you.

 

[buzz sawyer]

Darn good answer for your first post! We will look to hear more from you.

Ditto and +1.

I'm surprised some of the words in your first sentence were allowed! lol

 

[(WLL)]

Angiosperms take their cues to flower from vernalization (temperature) or photoperiodism (light).

Plants that exhibit photoperiodism are one of either long day or short day. Now, here's where it gets confusing, it's not the day length that's actually important but the length of night.

So, a long day plant requires less than a specific hours of night. These are usually plants that flower in the spring or summer. Short day plants require more than a specific amount of night to begin flowering. Short day plants can be inhibited from flowering if they experience flashes or sustained light.

Photoperiod plants use a light receptive chemical called phytochrome. Phytochrome is sensitive to the red and far-red region of the visible light specrtrum. So, red and far-red light can effect certain plants, disrupting their circadian rythm, or daily cycle.

I hope this helps.

thanx for your help and im gonna look into this more. ive been having some trouble finding info on this subject. if the light is under the leaves will it still use the light like its overhead? my guess is no, but im only guessing.

 

[user 23728]

While there are more chloroplasts in the upper or adaxial surface of a leaf, light will still be absorbed from all directions. This is shown when plants bend toward a source of light, this is called phototropism.

If you're looking at a specific circumstance rather than general knowledge, first determine when the tree flowers. If it's spring/summer, you probably don't have to worry. If it's late summer/fall, then consider the strength of light source around the tree and determine if there has been problems with the tree flowering in the past.

 

[John Paul Sanborn]

So, a long day plant requires less than a specific hours of night. These are usually plants that flower in the spring or summer. Short day plants require more than a specific amount of night to begin flowering. Short day plants can be inhibited from flowering if they experience flashes or sustained light.

The pointesttia is a very good example, to get the red bracts it needs around 14 hours of continuous dark, for more then a month, for the color change. It is very easy to throw it off

 

[treemandan]

are trees affected when bright lights shine all night?

Mine are, you betcha.

 

[(WLL)]

:hmm3grin2orange:

Mine are, you betcha.

:hmm3grin2orange:

 

[M.D. Vaden]

The pointesttia is a very good example, to get the red bracts it needs around 14 hours of continuous dark, for more then a month, for the color change. It is very easy to throw it off

Reminds me of my roommates growing plants in a closet when we were about 19 years old, near 1980.

Kept 18 hours of continuous light for months, then a reduction in hours to simulate reduced day-length started to initiate flowers and buds.

Also, I've watched - recently, past few years - a purple beech under the street lamp at a Denny's restaurant in Beaverton, Oregon. The leaves near the light stay on the tree well into winter, almost to February.

 

[PB]

Angiosperms take their cues to flower from vernalization (temperature) or photoperiodism (light).

Plants that exhibit photoperiodism are one of either long day or short day. Now, here's where it gets confusing, it's not the day length that's actually important but the length of night.

So, a long day plant requires less than a specific hours of night. These are usually plants that flower in the spring or summer. Short day plants require more than a specific amount of night to begin flowering. Short day plants can be inhibited from flowering if they experience flashes or sustained light.

Photoperiod plants use a light receptive chemical called phytochrome. Phytochrome is sensitive to the red and far-red region of the visible light specrtrum. So, red and far-red light can effect certain plants, disrupting their circadian rythm, or daily cycle.

I hope this helps.

Couldn't have said it better.

 

[suprherosndwch]

Vaden hit at the biggest problem with lights on trees. It confuses them as to what time in the year it is, so they often don't drop there leaves in the fall as soon as they should. This can cause a tree to hold on to it's leaves when that first heavy snow hits, causing more branch breakage.

 

[user 23728]

Vaden hit at the biggest problem with lights on trees. It confuses them as to what time in the year it is, so they often don't drop there leaves in the fall as soon as they should. This can cause a tree to hold on to it's leaves when that first heavy snow hits, causing more branch breakage.

This is a good point, light can play a role in plants hardening off for winter, but another common reason for this is likely to be fertilizing with nitrogen late in summer or fall.

There are many variables that determine bud set, flower development, leaf abscission etc. it's a challenge to know the determining factor. But keeping an open mind to many potential causes is good practise. Thanks for bringing this up.

 

[PB]

I looked for differences in trees growing near street lights and those not growing near night light for years and have yet to see any difference in bud break, onset of fall dormancy or winter time leaf holding. A good friend of mine has done quite a bit of research and manipulation on photo period response in hostas for crossing early and late flowering cultivars and hosta do have quite a response. It was his research that got me looking for photoperiod responses in trees starting about 1994.

I wouldn't expect to see any pre-mature or late dormancy issues due to street lights. Plants rely on multiple cues, not just length of day.

I would expect the trees to be under considerable stress compared to the plants grown away from lights. During the day harmful toxins build up from the usual metabolic processes and during the night they are scavenged and the cells return to the normal state. After long periods of light, I would assume that these reactive molecules are in extreme concentrations. This is only speculation, and haven't done any research on the subject.