Using eDNA to assess the effects of Sierra Nevada meadow restoration on invasive species and sensitive amphibians

Primary author: Nicolette Nelson
Faculty sponsor: Jonah Piovia-Scott

Primary college/unit: Arts and Sciences
Campus: Vancouver


Managers in the Sierra Nevada are increasingly restoring degraded wet meadows in order to recover essential ecosystem services (e.g. water storage and filtration) and to benefit native wildlife. These projects may increase available habitat for federally-listed amphibians, but some projects have unintentionally prompted the spread of invasive species that negatively impact native amphibians through predation, competition, and disease. In order to assess the effects of meadow restoration on invasive species and sensitive amphibians, we used a backpack sampler to collect environmental DNA (eDNA) samples at 23 restored and 23 paired unrestored Sierra Nevada meadows during the summers of 2018 and 2019. Quantitative PCR was used to detect the presence of American bullfrogs (Lithobates catesbeianus), Amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd), and Sierra Nevada yellow-legged frogs (Rana sierrae). R. sierrae were detected at only one site, which may be explained by the relatively low elevation of study sites and the degraded condition of unrestored meadows. Preliminary analysis suggested that L. catesbeianus were associated with pond-and-plug restoration sites, which result in the creation of novel permanent ponds, and Bd was slightly associated with bullfrogs. Our results indicate that wet meadow restoration in the Sierra Nevada may not be directly benefiting sensitive amphibians. Additionally, pond-and-plug restoration may facilitate the spread of some invasive species more than other restoration methods such as beaver dam analogues that aim to mimic natural meadow formation processes.