PARENT SESSION
Contributed Oral Session 7: Disturbance Ecology: Fire; Litter; Animal response
Monday, August 8, 8:00 AM - 11:30 AM, Meeting Room 518 A, Level 5, Palais des congrès de Montréal

The tension between fire risk and carbon storage in U.S. ecosystems.

Girod, Carolyn^{*,1, 2}, Hurtt, George^{1, 2}, ¹ Institute for the Study of Earth, Oceans, and Space, Durham, NH, USA² Department of Natural Resources, Durham, NH, USA

ABSTRACT- Fire risk and carbon storage are related environmental issues because fire suppression results in carbon storage through the buildup of woody vegetation, and stored carbon is a fuel for fires. The sustainability of the U.S. carbon sink and the extent of fire activity in the next 100 years depend in part on the type and effectiveness of fire suppression employed. Previous studies have bracketed the range of effects from unlimited fire suppression capability to complete failure (Hurtt et al. 2002). To improve these estimates, it is necessary to explicitly account for fire suppression in terrestrial models. We developed a new fire suppression sub-model that estimates the spatiotemporal pattern of suppression across the United States using gridded data on biomass, climate, population, and economic factors. The model was calibrated to 1°x1° burned area statistics from the Global Burnt Area 2000 Initiative (GBA-2000), and satisfied three important diagnostic comparisons, including total burned area, fire size distribution, and spatial fire pattern. The calibrated fire-suppression model was implemented in a spatially explicit ecosystem model (Miami-LU) and used to analyze 184 scenarios of future fire risk and suppression strategies. Under scenarios of future climate change, burned area and carbon emissions both increased dramatically in scenarios where fire suppression efforts were not adjusted to match new patterns of fire risk. Under a business-as-usual scenario, there was a 15% increase in annual burned area and 4 Pg reduction in carbon storage by 2100 because of fuel accumulation in fire prone areas. Fuel reducing ecosystem management strategies reduced burned area and fire risk, but also limited carbon storage. Non-fuel reducing strategies on the other hand, reduced burned area and increased carbon storage, but also increased fire risk. These results suggest that to promote carbon storage and minimize fire risk in the future, fire suppression efforts will need to be increased, spatially adjusted, and employ a mixture of fuel reducing and non-fuel reducing strategies.

Key words: fire model, carbon storage, suppression, ecosystem management