Informing management of rare species with an approach combining scenario modeling and spatially explicit risk assessment

Wildlife managers are tasked with identifying and managing stressors that threaten persistence of populations. We demonstrate an approach to land-use planning that combines scenario modeling and ecological risk assessment to map and quantify risk to population persistence for three rare prairie species in Washington State, USA. Following corroboration of model output, we found that of the management scenarios considered, only a scenario with year-round restrictions on use of off-road vehicles, digging, and camping enforced in all potential habitat reduces risk to the species. Decreased risk is focused primarily in two patches of prairie habitat in our study area, indicating stringent restrictions need not be applied broadly. However, one area is not easily accessed by two of the three species considered, suggesting reintroductions to suitable but inaccessible habitat may play an important role in management of these species. Our analyses suggest changes in land use and management that might improve habitat for rare species, with options for minimizing monetary and social costs. Because the proposed approach relies on hypothetical management scenarios and uses a model flexible in data requirements to provide spatially explicit output, it can be used to inform adaptive management of rare species in diverse land-planning processes and will be especially useful when management decisions must be made under time or cost constraints.