Adaptational responses to elevated CO{sub 2} concentrations by a Sierra-Nevadan dominant species: Pinus ponderosa

Journal Article · Thu Jun 01 04:00:00 EDT 1995 · Bulletin of the Ecological Society of America

OSTI ID:95870

Pushnik, J C; Houpis, J L.J.; Bauer, S M ^[1]

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1. California State Univ., Chico, CA (United States)

Seedlings of Pinus ponderosa a canopy dominant species, were grown in environmentally controlled chambers under ambient (350 {mu}L{center_dot}L{sup -1}) and increased carbon dioxide conditions (525 {mu}L{center_dot}L{sup -1} and 700 {mu}L{center_dot}L{sup -1}) for 9 months. Overall growth morphology exhibited significant changes including decreases in stem length and total leaf area. Needles had a tendency toward larger cross-sectional areas, increased development of vascular tissues and higher specific leaf mass. Physiologically, the trees exhibited increased carbon assimilation rates (A), internal CO{sub 2} (C{sub i}) and chlorophyll content, while the atmospheric CO{sub 2} ratio (C{sub i}/C{sub a}) ratio remained constant. Photochemical efficiencies were unaffected by CO{sub 2} treatments. Assessments of leaf biochemistry revealed increases in specific enzyme activities of ribulose 1,5 bisphosphate carboxylase (RuBCase) and sucrose phosphate synthase (SPS). These data are evaluated for specific effects on regulatory points in the carbon acquisition and allocation pathway.

• OSTI ID: 95870
• 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: 2 Vol. 76; ISSN BECLAG; ISSN 0012-9623
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BIOLOGICAL ADAPTATION
BIOLOGICAL EFFECTS
CARBON DIOXIDE
ECOLOGICAL CONCENTRATION
PINES
PLANT GROWTH