TY - JOUR
T1 - Interaction of elevated CO2 and O3 on growth, photosynthesis and respiration of three perennial species grown in low and high nitrogen
AU - Volin, John C.
AU - Reich, Peter B.
PY - 1996/8/1
Y1 - 1996/8/1
N2 - Seedlings of three species native to central North America, a C3 tree, Populus tremuloides Michx., a C3 grass, Agropyron smithii Rybd., and a C4 grass, Bouteloua curtipendula Michx., were grown in all eight combinations of two levels each of CO2, O3 and nitrogen (N) for 58 days in a controlled environment. Treatment levels consisted of 360 or 674 μmol mol-1 CO2, 3 or 92 nmol-1 O3, and 0.5 or 6.0 mM N. In situ photosynthesis and relative growth rate (RGR) and its determinants were obtained at each of three sequential harvests, and leaf dark respiration was measured at the second and third harvests. In all three species, plants grown in high N had significantly greater whole-plant mass, RGR and photosynthesis than plants grown in low N. Within a N treatment, elevated CO2 did not significantly enhance any of these parameters nor did it affect leaf respiration. However, plants of all three species grown in elevated CO2 had lower stomatal conductance compared to ambient CO2-exposed plants. Seedlings of P. tremuloides (in both N treatments) and B. curtipendula (in high N) had significant ozone-induced reductions in whole-plant mass and RGR in ambient but not under elevated CO2. This negative O3 impact on RGR in ambient CO2 was related to increased leaf dark respiration, decreased photosynthesis and/or decreased leaf area ratio, none of which were noted in high O4 treatments in the elevated CO3 environment. In contrast, A. smithii was marginally negatively affected by high O4.
AB - Seedlings of three species native to central North America, a C3 tree, Populus tremuloides Michx., a C3 grass, Agropyron smithii Rybd., and a C4 grass, Bouteloua curtipendula Michx., were grown in all eight combinations of two levels each of CO2, O3 and nitrogen (N) for 58 days in a controlled environment. Treatment levels consisted of 360 or 674 μmol mol-1 CO2, 3 or 92 nmol-1 O3, and 0.5 or 6.0 mM N. In situ photosynthesis and relative growth rate (RGR) and its determinants were obtained at each of three sequential harvests, and leaf dark respiration was measured at the second and third harvests. In all three species, plants grown in high N had significantly greater whole-plant mass, RGR and photosynthesis than plants grown in low N. Within a N treatment, elevated CO2 did not significantly enhance any of these parameters nor did it affect leaf respiration. However, plants of all three species grown in elevated CO2 had lower stomatal conductance compared to ambient CO2-exposed plants. Seedlings of P. tremuloides (in both N treatments) and B. curtipendula (in high N) had significant ozone-induced reductions in whole-plant mass and RGR in ambient but not under elevated CO2. This negative O3 impact on RGR in ambient CO2 was related to increased leaf dark respiration, decreased photosynthesis and/or decreased leaf area ratio, none of which were noted in high O4 treatments in the elevated CO3 environment. In contrast, A. smithii was marginally negatively affected by high O4.
KW - Agropyron smithii
KW - Bouteloua curtipendula
KW - Populus tremuloides
KW - carbon dioxide
KW - nitrogen
KW - ozone
KW - photosynthesis
KW - relative growth rate
KW - respiration
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U2 - 10.1034/j.1399-3054.1996.970407.x
DO - 10.1034/j.1399-3054.1996.970407.x
M3 - Article
AN - SCOPUS:0030499123
SN - 0031-9317
VL - 97
SP - 674
EP - 684
JO - Physiologia Plantarum
JF - Physiologia Plantarum
IS - 4
ER -