Carbon dioxide and sour orange trees: Results of the longest CO{sub 2} enrichment experiment ever conducted

Book · Sat Dec 31 04:00:00 EST 1994

OSTI ID:182836

Idso, S B; Kimball, B A ^[1]

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1. Water Conservation Lab., Phoenix, AZ (United States)

In July of 1987, eight sour orange tree seedlings were planted in the ground at Phoenix, Arizona, and surrounded in pairs by four, clear-plastic-wall, open-top enclosures through which air has been continuously circulated at a rate of four enclosure-volume exchanges per minute. In November of that year, two of the four enclosures had the CO{sub 2} content of the air moving through them increased by approximately 300 ppm above that moving through the other two enclosures, which receive air of approximately 400 ppm CO{sub 2}. Numerous measurements have been made on the trees over the course of the past six and a half years. The authors report results for leaf net photosynthesis and dark respiration rates, trunk and branch volumes, fine-root biomass, and fruit production. The major conclusion to be drawn from the data is that the 75% increase in the CO{sub 2} content of the air has increased total tree productivity by approximately 170 %. Most of this large growth enhancement developed over the first two years of the experiment, and it has remained at this high constant value ever since. 38 refs., 5 figs.

• OSTI ID: 182836
• Report Number(s): CONF-940426--; ISBN 0-923204-11-3
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
AIR POLLUTION
BIOLOGICAL EFFECTS
CARBON DIOXIDE
EXPERIMENTAL DATA
FRUIT TREES
ORANGES
PLANT GROWTH