| MadSci Network: Botany |
Yes, plants can conduct photosynthesis at night if there is sufficient electric light. I'm not sure anyone has measured photosynthesis in trees covered with Christmas lights. Enough Christmas lights, especially white lights, would provide sufficient light for photosynthesis. The photosynthesis rate might not be very high compared to daytime. It might not even be net photosynthesis. Net photosynthesis occurs when more carbon dioxide is fixed in photosynthesis than is produced in cellular respiration. With dim light, photosynthesis may still be occuring even if there is net carbon dioxide production by the photosynthetic leaf. The light level at which the carbon dioxide used in photosynthesis equals the carbon dioxide produced by cellular respiration is called the light compensation point. The light level of electric lamps falls rapidly as you move away from the lamp so the closer the leaf is to the lamp, the better it is for photosynthesis. As long as the lamps are not too hot for the leaf, there is no problem. Leaves can touch fluorescent lamps without heat damage but large incandescent bulbs are too hot for leaves to touch them without damage. References Hershey, D.R. 1991. Plant light measurement and calculations. American Biology Teacher 53:351-353. Re: can bean plants grow by moonlight?
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