PARENT SESSION
Symposium #13: Fire suppression impacts in crown fire ecosystems.
Sponsored by ESA Vegetation Section
Organized by: J. E. Keeley and E. A. Johnson.
Wednesday, August 8, 2001. 8:00 AM to 12:00 PM. Lecture Hall
Fire management impacts on fire regimes in California shrublands.
Keeley, Jon1,2, Fotheringham, C.2, 1 2
ABSTRACT- The historical variability in fire regime is a conservative indicator of ecosystem sustainability and thus understanding the natural role of fire in chaparral ecosystems is necessary for proper fire management. It has been suggested that the "natural" fire regime was one of frequent small fires that fragmented the landscape into a fine-grained mixture of age classes that precluded large catastrophic fires. Some researchers claim this regime was lost because of highly effective fire suppression and, if fire managers could "restore" a regime of frequent fires with widespread prescription burning, they could eliminate the hazard of catastrophic fires. Historical records suggest that the natural fire regime in southern California shrublands was rather coarse-grained and not substantively different from the contemporary regime. These findings raise questions about the appropriate management strategy and in particular the role of prescription burning. There is no evidence that prescribed burning in these shrublands provides any resource benefit and therefore fire hazard reduction would be the primary justification. It is argued that attempts to create landscape age mosaics by rotational burning are not a cost effective method of controlling catastrophic wildfires. Due to the nature of fuel distribution in these shrublands, often the required prescription weather conditions preclude burning at rotation intervals sufficient to affect the control of fires ignited under severe weather conditions. There is no evidence that fire management policies have created the contemporary fire regime dominated by massive Santa Ana wind-driven fires. Increased expenditures on fire suppression and increased loss of property and lives are the result of human demographic patterns that place increasing demand on fire suppression forces.
KEY WORDS: California, chaparral, wildfires, management