Impacts of laurel wilt disease on native Persea ecosystems: (Project SO-EM-B-12-05).
The objectives of this project were to document the range-wide population impacts of LWD, to describe community types associated with Persea, to characterize the patterns of mortality and regeneration of Persea after infestation, and to quantify changes in fuel and invasive plants. The trend line for the range-wide population estimates from 2003-11 showed significant negative curvature, suggesting that the redbay population is declining. The population in Georgia significantly decreased from approximately 241.1 ± 11.9 million stems in 2003 to 150.3 ± 7.9 million in 2011. Redbay densities decreased significantly in plots surveyed before and after the reported infection by an average of 89.6 live redbay stems/ha. Number of years since LWD infection was the most significant variable, with every increase in 1 year resulting in a 153.7% increase in odds of death. Diameter was also a significant predictor, with an increase of 1 cm diameter at breast height (d.b.h.) resulting in a 5.0% increase in odds of death. Contrary to initial fears, this study suggests that the native Persea species in the USA are not on the immediate verge of extinction from LWD at this time. However, it is still too early to say whether these species will fully recover from the disease. Whether Persea recovers completely hinges on the ability of X. glabratus to maintain low populations in the long-term.