Oxygen Level and Photosynthesis
Date: Summer 2009
Does a decrease in the amount of oxygen in the air lead to a
lower rate of photosynthesis in a plant?
Since photosynthesis consumes carbon dioxide from the atmosphere (or sea water)
to produce sugars and oxygen, a low level of oxygen in the atmosphere certainly
will not slow down photosynthesis.
A very high level of oxygen may inhibit the photosynthesis reaction if the pressure
of oxygen outside is such that the plant has difficulty in getting rid of its 'waste'
Farmers growing in greenhouse atmospheres have found that they can increase the rate
of photosynthesis, and make plants grow faster if they increase levels of carbon
dioxide within the greenhouse. To achieve this, some farmers have attached feedlines
to capture CO2 from furnaces or incinerators or even from diesel generators and pump
it into the greenhouses. Even ordinary greenhouses need to be ventilated to prevent
the depletion of CO2 which can lead to growth slowing.
Tennant Creek High School
Yes, usually although there are exceptions. The following should be helpful:
Anthony Brach Ph.D.
One of the terms you may look up is photorespiration. This is the process many
plants use when oxygen availability is low. It slows down, but does not completely
stop sugar production.
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Update: June 2012