Submitted to: Wetlands Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 15, 1997
Publication Date: N/A
Interpretive Summary: Wetlands are being lost at an alarming rate throughout the world. Many government agencies are taking drastic and expensive steps to preserve the precious few that remain. One of the most vital preservation programs involves the restoration of the Everglades system in southern Florida. Although vital areas can be set aside to protect them from development, they remain vulnerable to invasion by exotic species. Invasive weeds, in particular, are potent agents of environmental change that threaten to frustrate restoration efforts. The Australian tree Melaleuca quinquenervia, is highly invasive in south Florida wetlands, where it infests 202,000 ha. These wetlands, once dominated by native sedges (sawgrass), are being transformed into melaleuca swamps, with major environmental and economic impacts. Current management requires the use of herbicides, mechanical or hand removal of plants, flooding, and prescribed burning. Insufficient information, high costs, non-target impacts, and the resilience of melaleuca trees (trunk and root sprouts and massive canopy seed banks) limit the effectiveness of these methods. Biological control offers long-term effectiveness. The leaf weevil Oxyops vitiosa Pascoe, a natural enemy of M. quinquenervia in Australia, will soon be released to control this weed in Florida. Other biological control agents are being developed that should become available during the next few years.
Technical Abstract: Invasive weeds are potent agents of environmental changes on local to global scales. Wetlands are valuable environments that frequently are impinged by a variety of threats including invasive weeds. Melaleuca quinquenervia (Cav.) S. T. Blake (Broad-leaved Paperbark), though experiencing major diminishment of native populations in Australia, is naturalized and highly invasive in most wetland habitats of south Florida, where it infests more than an estimated 202,000 ha. Wetlands in south Florida including such renowned areas as the Everglades are being transformed into M. quinquenervia swamps, with major environmental and economic impacts. Current management methods include herbicides, mechanical or hand removal of plants, flooding, and prescribed burning. Insufficient information, high costs, non-target impacts, and the resilience of M. quinquenervia (trunk and root sprouts and massive canopy seed banks) greatly constrain the effectiveness of these control methods. Biological control offers long-term management potential, most likely by reducing the rate of spread and by reducing the vitality and growth rate of plants, thus rendering them more vulnerable to other environmental stresses and control methods. The leaf weevil Oxyops vitiosa Pascoe, a natural enemy of M. quinquenervia in Australia, will likely be the first biocontrol agent released against the weed in Florida. More information is needed, especially ecological data, to better understand the invasiveness of M. quinquenervia in Florida and to facilitate its management there.