How state regulations can limit the sale and spread of invasive plant species: an example from Florida.

Exotic species have long played an important role in the agricultural and ornamental plants of the United States. Florida has welcomed many of these species as warmly as tourists to its amusement parks. Estimates of up to 85% of invasive plant species in Florida were introduced as ornamentals through the horticulture industry. Agricultural introductions, such as non-native grasses for forage, provide another source of pest plants. Among our most notorious ornamental introductions are Melaleuca quinquenervia (punktree) and Schinus terebinthifolia (Brazilian pepper or Christmasberry-tree). Natural dispersal through disturbances such as hurricanes also introduce or spread non-native plant species. Traditionally, state and federal governments focused regulatory activity on noxious weeds known to cause negative economic impacts on agriculture, but since 2002, Florida has added invasive plant species that disrupt natural systems. As part of the Florida Department of Agriculture and Consumer Services, the Division of Plant Industry (DPI) has responsibility for protecting native and commercially grown plant species, in part by regulating noxious weeds and invasive species. Without a requirement for screening exotic species before they are released, Florida's regulatory mechanisms depend on listing species after they prove to be pests. DPI enforces regulations limiting the movement of noxious weeds and carries out decisions made by the state Noxious Weed Review Committee to add or remove species from the list of regulated plants or to exempt sterile cultivars of listed species. The procedures followed by the Noxious Weed Review Committee provide a science-based process for deciding whether a plant should be included on the Florida Noxious Weed and Invasive Plant List. This process can provide a model of regulatory activity for conservation biologists in other states. [ABSTRACT FROM AUTHOR]