[Plant-biology] Re: Plantbio Digest, Vol 43, Issue 2

Ronald Maldonado Rodriguez via plantbio%40net.bio.net (by ronaldmr from yahoo.com)
Mon Dec 22 03:26:27 EST 2008


I believe Marine aquatic plant physiology can help also to answer that question.

Plants growing at 1, 5, 10, 20, or even 50 m undersea have different hyperbaric conditions and therefore, some effect on marine vegetation physiology should be observed.

In internet we find any kind of references like the guy who claims that plants do not stop growing under hyperbaric conditions:

"In two years a
tomato plant grown in a hyperbaric chamber grew to a height of 16 feet
and produced 930 tomatoes! That's not all! It didn't stop growing! "
at this site: http://www.geocities.com/johnh_vanbc/bible/preflood.html

An interesting question answer we find in this Web site:
http://www.madsci.org/posts/archives/2004-02/1075764676.Bt.r.html


Re: Can plants grow at gretaer than atmospheric air pressure
Date: Mon Feb  2 17:18:09 2004

Posted By: David Hershey, Faculty, Botany, NA

Area of science: Botany

ID: 1075527828.Bt

Message:


Growing plants at above normal atmospheric pressure would involve a hyperbaric 
chamber. One recent study on ginkgo found as much as a 250% increase in the 
photosynthesis rate when the carbon dioxide was increased 500% and atmospheric 
pressure was increased 25%. I contacted the lead author, Sara Decherd, and she 
kindly told me that they found no significant effect on photosynthesis with a 
25% increase in atmospheric pressure alone. She was also not aware of much 
other research on plant growth in hyperbaric chambers. It seems to be an area 
that has not been thoroughly studied. The ginkgo research was recently 
featured in a news release, "A Lot of Hot Air: How the Dinosaurs Grew So 
Monstrous."  

NASA has done work on growing plants at less than atmospheric pressure in 
hypobaric chambers. Hypobaric greenhouses with one-sixteenth the pressure of 
an Earth atmosphere may be required for Mars colonization. 

At normal atmospheric pressures, increasing the carbon dioxide concentration 
up to about 1,000 ppm often increases plant growth. Current atmospheric carbon 
dioxide is about 360 ppm. Thus, you might expect a positive effect on plant 
growth in a hyperbaric chamber. I doubt a soda bottle would be a satisfactory 
hypobaric chamber. It would be difficult and expensive for a school student to 
maintain an elevated carbon dioxide level in a hyperbaric plant growth chamber 
because a plant can rapidly deplete the carbon dioxide given its low 
concentration and the limited chamber volume. Be very cautious if you try to 
make your own hyperbaric chamber because an explosion is always a possibility.

It would be much easier to demonstrate effects of carbon dioxide enrichment at 
normal atmospheric pressures. A soda bottle system to inexpensively induce 
carbon dioxide deficiency in plants can be built using rubber stoppers, 
aquarium tubing, aquarium valves and an aquarium air pump (Hershey 1992, 
1995). The same system could be used to elevate the carbon dioxide level using 
dry ice or acid mixing with calcium carbonate as a source of carbon dioxide=


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