Biogeography and Contested Invasiveness of Pistia stratiotes in Florida

Keywords: Pistia stratiotes, biogeography, invasive species
Session Type: Virtual Poster Abstract
Day: Sunday
Session Start / End Time: 2/27/2022 05:20 PM (Eastern Time (US & Canada)) - 2/27/2022 06:40 PM (Eastern Time (US & Canada))
Room: Virtual 32

Abstract

The botanist William Bartram described a large number of plants, animals, and cultural landscapes in his late 18th century travels through the American south. Ecosystems and species assemblages identified by Bartram are often used as a foundation for constructing ranges of native species in a time before widespread colonial settlement and development in this region. However, the floating aquatic plant, Pistia stratiotes (commonly called "water lettuce"), is a notable exception to this general narrative. Described by Bartram in numerous locations and in large abundances throughout the St. Johns River and Suwannee River watersheds of Florida, P. stratiotes has nevertheless been classified and managed as an "invasive exotic" species in Florida since the mid 20th century. While there was at one time some uncertainty about the spatio-temporal origins of P. stratiotes dispersal into Florida, there is now sufficient paleo-botanical and ecological data to indicate that P. stratiotes has been present in the Florida peninsula since at least 14,000 BP, with no evidence to suggest that this paleo-dispersal was likely to have been human-mediated. Interactions of management entities with such evidence regarding the nativity of P. stratiotes have included an interesting diversity of over-acceptance, utter denial, complete disregard, and bureaucratic ambivalence. This curious example may provide some insight regarding the social and geographic malleability of terms like "invasive," "exotic," and "native" within ecosystem management discourses, especially when the ecological behavior of a species conflicts with romantic visions of the pristine.