Canopy photosynthesis of crops and native plant communities exposed to long‐term elevated CO 2

• Published in: Plant, Cell & Environment
• Main Authors: DRAKE, B. G., LEADLEY, P. W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1991
• Subjects: Tundra
• Online Access: http://dx.doi.org/10.1111/j.1365-3040.1991.tb01448.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-3040.1991.tb01448.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3040.1991.tb01448.x

Abstract. There have been seven studies of canopy photosynthesis of plants grown in elevated atmospheric CO 2 : three of seed crops, two of forage crops and two of native plant ecosystems. Growth in elevated CO 2 increased canopy photosynthesis in all cases. The relative effect of CO 2 was correlated with increasing temperature: the least stimulation occurred in tundra vegetation grown at an average temperature near 10°C and the greatest in rice grown at 43°C. In soybean, effects of CO 2 were greater during leaf expansion and pod fill than at other stages of crop maturation. In the longest running experiment with elevated CO 2 treatment to date, monospecific stands of a C 3 sedge, Scirpus olneyi (Grey), and a C 4 grass, Spartina patens (Ait.) Muhl., have been exposed to twice normal ambient CO 2 concentrations for four growing seasons, in open top chambers on a Chesapeake Bay salt marsh. Net ecosystem CO 2 exchange per unit green biomass (NCE b ) increased by an average of 48% throughout the growing season of 1988, the second year of treatment. Elevated CO 2 increased net ecosystem carbon assimilation by 88% in the Scirpus olneyi community and 40% in the Spartina patens community.