Considerations for Managing Riparian Livestock Grazing in the Western US to Maintain Trout Populations

Although livestock grazing is nearly ubiquitous throughout western grasslands, management of riparian grazing to promote trout populations continues to be controversial.  I review evidence from throughout the central Rocky Mountains, Great Basin, and the Columbia Plateau that suggests that trout populations may be maintained where riparian grazing is properly managed.  Rotational grazing systems hold promise for maintaining, even improving, trout populations in rangeland streams, but will likely need to incorporate longer-term periods of rest for riparian pastures and more intensive management in arid climates.  Major challenges that continue to limit our ability to effectively manage riparian grazing for trout populations are a poor understanding of the relative importance of prey resources and physical habitat, difficulties with evaluating and implementing management at spatial scales relevant to fish population processes, and limited research linking the effects of different grazing systems to fish populations.  Ultimately, it is unlikely that a standardized approach to managing riparian grazing will be successful in maintaining trout populations.  In contrast, regionally tailored approaches that consider local climate, vegetation communities, wildlife populations, geology, historical grazing context, and the potential for local collaboration are needed to ensure that grazing strategies can be designed to complement efforts to conserve trout populations.