Seasonal Amphibian Species Richness and Population Fluctuations at Powdermill Nature Reserve, Pennsylvania, U.S.A.

Abstract. Amphibians are a highly vulnerable taxonomic group that have suffered population declines worldwide. As amphibians serve critical links between trophic levels and facilitate nutrient recycling, it is critical to understand how their species richness, abundance, and phenology shift over time. Because amphibian populations naturally fluctuate, short-term monitoring can provide insight into how amphibian communities respond to proximate changes in weather conditions, which is helpful for predicting long-term responses to climate change. We used pitfall traps to examine interannual variation of the amphibian community at Powdermill Nature Reserve (PNR) in Pennsylvania during 2020–2021 to provide critical details for future long-term monitoring. Mean monthly temperature and precipitation did not vary significantly between years, but monthly captures per sampling effort declined and monthly biomass per sampling effort increased from 2020 to 2021. Despite a lack of significant relationships between total amphibian captures and temperature and precipitation, peak abundance shifted earlier, and individuals were larger in 2021 compared to 2020. Interestingly, individual species biomass was predicted by an interaction between temperature and precipitation, suggesting individual species will vary in vulnerability to climate change, but the amphibian community as a whole at PNR is resilient to minor fluctuations in temperature and precipitation.