Hurricane Impacts on Florida Rosemary Across the Northeastern Region of the Gulf Coast

Hurricanes represent a major source of stochastic disturbance to coastal plant communities, with the potential to temporarily alter both species composition and environmental characteristics. Ceratiola ericoides Michx. (Florida rosemary) is a dominant member of an association of xeric species known collectively as rosemary scrub, which occur on barrier islands along the Gulf Coast and in inland peninsular Florida scrub. Unlike interior populations of Florida rosemary, which are periodically reduced by fire, coastal populations of rosemary are likely to be influenced by hurricanes more than by fire, with resultant differences in the frequency of damage to adults. We quantified the impact of major hurricanes on coastal populations of Florida rosemary and examined the impact of storm surge, elevation, and time-since-hurricane on rosemary survival and resprouting in five populations on the Mississippi and Florida coasts. Ratio of living-to-dead rosemary shrubs was higher in two coastal populations not recently struck by a major hurricane than on three barrier islands affected in 2004 - 2005 by Hurricanes Ivan and Katrina. There was also a trend toward greater mortality from Hurricanes Ivan and Katrina on islands with lower elevation, but the difference was not statistically significant, perhaps reflecting similar impacts of these hurricanes and their occurrence in consecutive years. In contrast to previous observations of infrequently disturbed inland populations of Florida rosemary, which exhibited an obligate seeder strategy, coastal populations showed a significant capacity for resprouting following hurricane damage. Given a two-year or more delay in seedling establishment following severe damage to adults, resprouting could expedite post-hurricane recovery of these populations.