Diurnal patterns of photosynthetic response to elevated CO{sub 2} and nitrogen supply in Pinus taeda seedlings

Journal Article · Fri Sep 01 04:00:00 EDT 1995 · Bulletin of the Ecological Society of America

OSTI ID:107122

Lewis, J D; Griffin, K L; Thomas, R B ^[1]

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1. Duke Univ., Durham, NC (United States); and others

We examined the effects of elevated CO{sub 2} and nitrogen supply on diurnal patterns of photosynthesis in 22-week old Pinus taeda seedlings. Seedlings were grown at either 35 Pa or 70 Pa CO{sub 2} and with an adequate or limiting supply of nitrogen. Photosynthetic capacity (assimilation versus internal CO{sub 2} curves) was measured at 1030, 1200, 1330, 1500 and 1630 h. Elevated CO{sub 2} significantly increased photosynthesis, but significantly reduced rubisco activity and RuBP regeneration capacity. Limiting nitrogen supply significantly reduced photosynthesis, rubisco activity and RuBP regeneration capacity. Photosynthetic capacity declined significantly between 1030 and 1630. There were no interactions between CO{sub 2} supply, nitrogen supply and time of measurement. These results suggest that elevated CO{sub 2} reduces photosynthetic capacity in Pinus taeda, but does not affect diurnal patterns of photosynthesis.

• OSTI ID: 107122
• Report Number(s): CONF-9507129--
• Journal Information: Bulletin of the Ecological Society of America, Journal Name: Bulletin of the Ecological Society of America Journal Issue: 3 Vol. 76; ISSN BECLAG; ISSN 0012-9623
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BIOLOGICAL EFFECTS
CARBON DIOXIDE
DAILY VARIATIONS
NITROGEN
PHOTOSYNTHESIS
PINES
SEEDLINGS