Seasonal fine-root biomass development of sour orange trees grown in atmospheres of ambient and elevated CO2 concentration |
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Authors: | S. B. IDSO B. A. KIMBALL |
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Affiliation: | US Water Conservation Laboratory, 4331 E. Broadway, Phoenix, AZ 85040, USA |
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Abstract: | Sour orange trees have been grown from the seedling stage out-of-doors at Phoenix, Arizona, USA, in open-top enclosures with clear plastic walls for 3.5 years. For the last 3 years of this period, half of the trees have been continuously exposed to air enriched with CO2 to 300 μmol mol?1 above the ambient concentration. At 2-month intervals over the last 12 months, we have determined the fine-root biomass in the top 0.4 m of the soil profile beneath the trees. Results from both treatments define a single relationship between fine-root biomass and trunk cross-sectional area. The data also show the CO2-enriched trees to have approximately 2.3 times more fine-root biomass in this soil layer than the trees grown in ambient air. |
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Keywords: | Citrus aurantium sour orange greenhouse effect carbon dioxide CO2 global change tree growth root growth |
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