In many semi-arid regions of the United States, hydrologic regimes have changed significantly due to anthropogenic factors, thus driving the creation of new plant assemblages that include invasive species. In the semi-arid Great Plains and Intermountain West regions, state governments are increasingly concerned about the myriad of impacts from invasive plant species on dwindling water supplies. Legal actions taken by states and initiatives led by organizations and recreationists have been the motivation behind efforts to eradicate invasive plants with the intention of improving stream flow, overall water availability, and critical habitat for several endangered species (e.g., whooping crane, piping plover, cinnamon teal, American avocet). Yet, little is known about 1) the political motivation and scientific basis for the management that has been employed and 2) the current status in terms of management outcomes. We address both areas in a review of the measures taken by Utah and Nebraska in managing a common invader: Phragmites australis (non-native common reed).
Results/Conclusions
The state of Nebraska has spent $6 million to control P. australis, which has infested much of the Platte River. In the state of Utah, P. australis has expanded to cover more than 90 km2 of Great Salt Lake wetlands. The management efforts in both states have focused on herbicide application integrated with mowing, grazing, or less frequently burning for biomass management. Phragmites australis populations have been reduced largely because of political pressure to prevent lawsuits stemming from outdoor enthusiasts and state water regulators. However, the initial management efforts will need to be sustained through the development of stronger partnerships between public land managers and land owners. Approaches will need to be continued or current ground will be lost along with millions of dollars and time spent. In Great Salt Lake wetlands, effective science-driven Phragmites management approaches have been developed but future success will be limited by funding, the scale of the invasion, intense Phragmites propagule pressure from the landscape, drought conditions that impede herbicide effectiveness, and untested revegetation practices.