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In our experiment we studied the respiratory qualities of green bark ceanothus (Ceanothus spinosus). Plants are generally thought to undergo respiration during the night, building up carbon dioxide stores that are released in response to light. In resprouts with large root crowns, such as C. spinosus, we expected to see large amounts of carbon dioxide released right after dawn. This can be shown with the use of a portable gas exchange system. In C. spinosus, we compared normal respiration rates, based on carbon dioxide expulsion, to values obtained at predawn. We were able to show that there is significant carbon dioxide expulsion that occurs in response to predawn sunlight. We predict this may be related to very high metabolic rates of the roots as the plant resprouts.

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