HR: 0830h
AN: B11D-0722    [PDF]
TI: Interannual Variation in the Response of Forest Productivity to Elevated Carbon Dioxide
AU: * De Lucia, E H
EM: delucia@uiuc.edu
AF: University of Illinois, Department of Plant Biology, Urbana, IL 61801 United States
AU: Moore, D J
EM: dmoore1@students.uiuc.edu
AF: University of Illinois, Department of Plant Biology, Urbana, IL 61801 United States
AU: Hamilton, J
EM: jhamilton@ithaca.edu
AF: Ithaca College, Department of Biology, Ithaca, NY 14850 United States
AU: Finzi, A
EM: afinzi@bio.bu.edu
AF: Boston University, Department of Biology, Boston, MA 02215 United States
AU: Pippen, J
EM: jspippen@acpub.duke.edu
AF: Duke University, Nicholas School of the Environment and Earth Sciences, Durham, NC 27708 United States
AU: Schlesinger, W H
EM: schlesin@duke.edu
AF: Duke University, Nicholas School of the Environment and Earth Sciences, Durham, NC 27708 United States
AB: Photosynthesis and respiration of forests contribute to the regulation of atmospheric carbon dioxide. To determine the capacity of forests to respond to increasing concentrations of atmospheric CO2, derived from anthropogenic sources, we exposed large replicated plots in a loblolly pine forest to atmospheric plus 20 Pa CO2 for seven years. While the average growth rate of trees has declined with time, the stimulation caused by elevated CO2 has remained between ~15 and 25 percent. The biomass increment of wood and litterfall, the two major components of net primary production in this forest, also were stimulated by elevated CO2. A preliminary analysis indicates that net primary production is correlated with growing season precipitation and the rate of nitrogen mineralization, but the magnitude of the stimulation caused by CO2 is related to temperature. In one year the trees exposed to elevated CO2 sequestered an additional 174 gC/m2 relative to trees under ambient conditions. As trees grow larger more N is immobilized in plant tissues suggesting that the growth response to CO2 may abate in the future. The stimulation of forest productivity by elevated CO2, while locally significant, is not likely to reduce the accumulation of C in the atmosphere as the cover of forests continues to decline globally.
UR: http://www.life.uiuc.edu/delucia/
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2003 Fall Meeting