Allometric determination of tree growth in a CO2-enriched sweetgum stand
Article first published online: 21 DEC 2001
Volume 150, Issue 2, pages 477–487, May 2001
How to Cite
Norby, R. J., Todd, D. E., Fults, J. and Johnson, D. W. (2001), Allometric determination of tree growth in a CO2-enriched sweetgum stand. New Phytologist, 150: 477–487. doi: 10.1046/j.1469-8137.2001.00099.x
- Issue published online: 21 DEC 2001
- Article first published online: 21 DEC 2001
- Received: 13 August 2000 Accepted: 17 November 2000
- basal area increment;
- elevated CO2;
- forest productivity;
- free-air CO2 enrichment (FACE);
- global change;
- Liquidambar styraciflua (sweetgum);
- tree growth
- • In a free-air CO2 enrichment (FACE) study, above-ground growth of Liquidambar styraciflua (sweetgum) trees was measured in a closed-canopy stand to test hypotheses about long-term effects of rising [CO2] in a deciduous forest.
- • Allometric relationships were established between above-ground dry mass and basal area, height, taper and wood density for all trees in the 314-m2 plots. Leaf area index was calculated from leaf litter mass.
- • In the first year of exposure, elevated [CO2] stimulated stand-level aboveground dry matter increment by 33%, but in the second year the growth stimulation was reduced to 15% and was no longer statistically significant. Leaf area index was not affected by CO2 enrichment in either year.
- • These results indicate that large trees that are no longer in an exponential growth phase retain the capacity to respond to elevated [CO2]. The combined 2-yr response of a 24% increase in growth per unit leaf area is consistent with predictions from earlier studies. A longer-term data set is needed to resolve the reason for different responses in the 2 years.