PARENT SESSION
Contributed Oral Session 67: Modeling: Nutrient Cycling; Food Webs
Tuesday, August 9, 1:30 PM - 5:00 PM, Meeting Room 520 C, Level 5, Palais des congrès de Montréal

Relative importance of multiple stresses on terrestrial carbon sequestration.

Kicklighter, David^*,1, Melillo, Jerry¹, Prinn, Ronald², McGuire, Anthony³, Felzer, Benjamin¹, Zhuang, Qianlai⁴, ¹ Marine Biological Laboratory, Woods Hole, Massachussetts, USA² Massachussetts Institute of Technology, Cambridge, Massachussetts, USA³ University of Alaska-Fairbanks, Fairbanks, Alaska, USA⁴ South Dakota School of Mines and Technology, Rapid City, South Dakota, USA

ABSTRACT- Several environmental factors influence carbon sequestration in natural terrestrial ecosystems including climate variability and change, atmospheric carbon dioxide concentrations, ozone pollution and atmospheric nitrogen deposition. To explore the relative importance of these factors on historical carbon sequestration, we conducted a series of global simulations with the Terrestrial Ecosystem Model (TEM). Our results indicated that 1.6 Pg C per year were stored in terrestrial ecosystems during the 1990s. Carbon dioxide fertilization accounted for about 60 percent of this sequestered carbon while atmospheric nitrogen deposition accounted for most of the remainder. Potential benefits of climate variability and change to carbon sequestration during this time period were compensated by the detrimental effects of ozone pollution. Preliminary analyses also suggested that land-use change would reduce our estimate of terrestrial carbon sequestration by about a third.

Key words: terrestrial carbon sequestration, CO₂ fertilization, atmospheric N deposition, ozone pollution