Carbon-nutrient interactions in response to CO/sub 2/ enrichment: physiological and long-term perspectives. [Quercus alba L]

Conference · Tue Jan 01 00:00:00 EST 1985

OSTI ID:6011043

Norby, R J; Pastor, J; Melillo, J M

The responses of forest trees to atmospheric CO/sub 2/ enrichment will depend in part on carbon-nutrient linkages. Insights into the possible long-term ecological consequences of CO/sub 2/ enrichment can be gained from studying physiological responses in short-term experiments. One-year-old white oak (Quercus alba L.) seedlings were grown in an unfertilized forest soil for 40 weeks in controlled-environment chambers with ambient (362 ..mu..L.L/sup -1/) or elevated (690 ..mu..L.L/sup -1/) CO/sub 2/. Seedling dry weight was 85% greater in the elevated CO/sub 2/ environment, despite a severe nitrogen deficiency in all seedlings. The increase in growth occurred without a concomitant increase in nitrogen uptake, indicating an increase in nitrogen-use efficiency in elevated CO/sub 2/. The weight of new buds was greater in elevated CO/sub 2/, suggesting that shoot growth in the next year would have been enhanced relative to that of seedlings in ambient CO/sub 2/. However, there was a lower amount of translocatable nitrogen in perennial woody tissue in elevated CO/sub 2/; thus, further increases in nitrogen-use efficiency may not be possible. The leaves that abscised from seedlings in elevated CO/sub 2/ contained higher amounts of soluble sugars and tannin and a lower amount of lignin compared with amounts in abscised leaves in ambient CO/sub 2/. Based on lignin to N and lignin to P ratios, the rates of litter decomposition might not be greatly affected by CO/sub 2/ enrichment, but the total amount of nitrogen returned to soil would be lower in elevated CO/sub 2/.

• Research Organization: Oak Ridge National Lab., TN (USA); Minnesota Univ., Duluth (USA). Natural Resources Research Inst.; Marine Biological Lab., Woods Hole, MA (USA). Ecosystems Center
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6011043
• Report Number(s): CONF-851050-1; ON: DE86007919
• Resource Relation: Conference: International symposium on whole-plant physiology: coupling of carbon, water, and nutrient interactions in woody plant soil systems, Knoxville, TN, USA, 6 Oct 1985; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CARBON DIOXIDE
BIOLOGICAL EFFECTS
OAKS
PRODUCTIVITY
EXPERIMENTAL DATA
EXPOSURE CHAMBERS
NITROGEN
QUANTITY RATIO
SEEDLINGS
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CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
DATA
DISTRIBUTION
ELEMENTS
INFORMATION
NONMETALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PLANTS
TREES
560303* - Chemicals Metabolism & Toxicology- Plants- (-1987)