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Title: Effects of subambient and elevated CO[sub 2] on photosynthesis in C[sub 3] and C[sub 4] plants

Conference · · Bulletin of the Ecological Society of America; (United States)
OSTI ID:6143683

Amaranthus retroflexus (C[sub 4]) and Abutilon theophrasti (C[sub 3]) were grown from seed at 4 CO[sub 2] partial pressures: 15 Pa (Pleistocene), 27 Pa (preindustrial), 35 Pa (current), and 70 Pa (future) in the Duke Phytotron under high light, nutrient and water conditions. Net photosynthesis at the growth CO[sub 2] partial pressures increased with elevated CO[sub 2] for C[sub 3] and C[sub 4] plants. Maximum photosynthetic rates increased by 27% for A. theophrasti grown at current CO[sub 2] compared with 15 Pa, and did not change in plants grown at 70 Pa compared with current CO[sub 2]. Similarly, carboxylation efficiency increased by 26% for plants grown at current CO[sub 2] compared with 15 Pa. The relative stomatal limitation to photosynthesis decreased linearly from 24% to 1% as CO[sub 2] Partial pressures increased from 15 to 70 Pa. Photosynthetic parameters for A. retroflexus changed only slightly over the entire range of CO[sub 2] partial pressures. Results indicate net photosynthesis was correlated with atmospheric CO[sub 2] partial pressures since the Pleistocene for C[sub 3], but not C[sub 4] plants.

OSTI ID:
6143683
Report Number(s):
CONF-930798-; CODEN: BECLAG
Journal Information:
Bulletin of the Ecological Society of America; (United States), Vol. 74:2; Conference: 78. annual Ecological Society of America (ESA) meeting, Madison, WI (United States), 31 Jul - 4 Aug 1993; ISSN 0012-9623
Country of Publication:
United States
Language:
English