Expansion and Impact of Laurel Wilt in the Florida Everglades

Laurel wilt, a vascular wilt disease caused by the vascular mycopathogen Raffaelea lauricola T. C. Harr. (Ophiostomatales: Ophiostomataceae), was first confirmed on Persea palustris (Raf.) Sarg. (Laurales: Lauraceae) in the Florida Everglades in Feb 2011. The abundance and range of occupancy of P. palustris symptomatic of laurel wilt were mapped in the Everglades tree islands in Mar 2011 and Jun 2013 using a digital aerial sketch mapping system. The disease's range of occupancy expanded from 4,925 to 133,740 ha during this 26-month period. Canopy disturbance was highly variable ranging from 0 to 50% canopy loss. However, tree island species composition data suggests that additional mortality of P. palustris is likely throughout the Everglades. The rapid loss of P. palustris in tree islands could lead to ecosystem level instability and invasion by exotic plant species.