Invasive Plants of Great Salt Lake Wetlands: What, Where, When, How, and Why?

Great Salt Lake (GSL) and its wetlands are recognized around the world for the valuable habitat they provide for millions of migratory birds. GSL wetlands are threatened by a number of invasive plants, the most problematic of which is non-native phragmites (Phragmites australis) although there are a number of other species that are concerning and also a target of management. In this chapter, we describe the major invasive plants of and their distributions across GSL wetlands, detail the mechanisms driving these plant invasions and their historical context, discuss why different invasive species present unwanted impacts, and synthesize best practices for invasive plant control for these species in GSL wetlands. Managers of GSL wetlands face a daunting task to control these plants, particularly in the case of phragmites, where hundreds of hectares of infestations must be treated and retreated annually. Eradication of phragmites will not be possible given its intense propagule pressure and dense seed banks, thus strategic and prioritized management approaches are critical. Future success for all invaders will be contingent upon continued cooperation between scientists and managers to develop robust treatment techniques and between managers to coordinate their management to reduce invader cover and impacts. Furthermore, future research and management priorities should include (1) limiting invader propagule pressure and seed bank densities, (2) optimizing native plant revegetation following invader removal, (3) early detection and control of new invaders that are likely to increase with climate change, (4) more refined hydrologic management to promote invader control, and (5) quantitative documentation of avian impacts from invaders, especially given the continental importance of this habitat to migratory birds. Despite the threats GSL and its wetlands face with anthropogenic development, water diversions, and climate change, we are optimistic that at least in the case of invasive species, collaborative and science-backed management can continue to be effective given current partnerships and practices.