Bringing back the trout: metapopulation viability of Bonneville cutthroat trout in a fire-impacted watershed

Wildland fires are becoming more frequent, larger, and more severe as forested western landscapes regress back toward natural mean fire frequencies after decades of fire suppression. The increasing prevalence of fire is often at odds with native trout conservation and restoration because fire causes locally high mortality and can suppress vital rates for several years. Using matrix population projection, I modeled the extinction rates of a Bonneville cutthroat trout (Oncorhynchus clarkii utah) metapopulation in a partially fragmented stream network in south-central Utah. I parameterized the model based on published vital rates for stream-dwelling Bonneville cutthroat trout, spatial connectivity between subpopulations within the metapopulation, and occurrence and synchrony of wildland fire. Model results indicate that resilience of Bonneville cutthroat trout metapopulations increases with increased subpopulation connectivity and reduced synchrony of fire perturbations. Managing native fish populations to increase resilience to wildfire should include removal of barriers, if possible, and promoting asynchronous fire occurrence to allow subpopulations of fish to recover and contribute to overall metapopulation stability