Survey of Threatened and Endangered Wetland and Aquatic Plants at Four Corps of Engineers Districts

摘要

The invasion of nuisance exotic plants has been identified as a major threat to the survival and recovery of many threatened and endangered plant species; however, little information exists as to the extent of this problem in wetland and aquatic habitats. Moreover, the impact of aquatic plant management practices on sensitive plant habitat is unknown. Surveys were conducted for four Corps of Engineers (CE) Districts (ST Paul, Seattle, Galveston, and Fort Worth) to identify and establish the location of both federal and state listed threatened and endangered aquatic and wetland plant species that may be at risk as a result of exotic plant invasions. Sixteen percent of the plants listed under the Endangered Species Act were identified as inhabitants of aquatic and wetland environments. On a national scale, the greatest numbers of these species occurred in California, Hawaii, and the southeastern coastal states. Most states within each surveyed CE District also recognized and listed species of local conservation concern, although the methods for listing and ranking and the legal status of these plants varied greatly from state to state. This data inquiry showed that numerous aquatic and wetland plant species are in jeopardy and that a need exists to inventory and manage CE wetland and aquatic resources for both federal- and state-listed threatened and endangered species. Future research is proposed to identify and evaluate the impact of chemical and integrated aquatic plant management strategies for managing non-native nuisance plant species that threaten sensitive aquatic and wetland habitats.