Thursday, August 9, 2007 - 8:00 AM

COS 119-1: Compatibility of herbicide treatment of the exotic vine Lygodium microphyllum and restoration of wetland plant communities on a river floodplain

Louis A. Toth, South Florida Water Management District

Reestablishment of floodplain wetlands is an integral component of the ongoing restoration of the channelized Kissimmee River in south, central Florida.  Restoration of wetland plant communities is expected to be driven by reestablishment of historical inundation regimes along 70 km of reconstructed river.  A recent invasion of the floodplain by the exotic Old World climbing fern, Lygodium microphyllum, threatens this premise of hydrologic restoration and was addressed by aerial application of the non-selective herbicide glyphosate.  Vegetation recovery following the herbicide application was compared to two nearby untreated sites where similar mesophytic shrub communities had been subjected to increased hydroperiods and depths.   After the initial decrease in plant cover due to the glyphosate treatment, wetland vegetation quickly reestablished in treated plots and had similar plant community structure as untreated plots.  The mesophytic assemblage of Myrica cerifera, shade-tolerant ferns and Lygodium was replaced by a recovering community that reflected exposure to prolonged inundation regimes and was dominated by Ludwigia peruviana, Ludwigia leptocarpa, Scirpus cubensis and floating species.  Results indicate herbicide application did not impact the restoration trajectory of the wetland community.