DEMOGRAPHY OF ADENOSTOMA-FASCICULATUM AFTER FIRES OF DIFFERENT INTENSITIES IN SOUTHERN CALIFORNIA CHAPARRAL

Changes in the population structure of the lignotuberous resprouter Adenostoma fasciculatum were investigated by experimentally burning at various intensities an old stand in southern California chaparral. Survival after fire, time of resprouting, herbivory, and survival after resprouting were monitored for more than 1 year after the fire. Greater fire intensity increased plant mortality and the size of plants that died as a consequence of the fire. Time from the fire until resprouting increased with increasing fire intensity and was related to plant size: the larger the plants the earlier they resprouted. Post-resprouting mortality also increased with fire intensity and was related to time of resprouting. Herbivory increased with fire intensity and the size of plants affected by it changed with the intensity of the fire. Fire intensity had profound direct and indirect effects on the population structure of Adenostoma fasciculatum. Plant size strongly determined the direct and indirect lethal effects of fire.