Exploratory Survey of Salamanders in Pennsylvanian Forests with Dense Understories of Berberis thunbergii (Japanese Barberry), an Invasive Shrub

Ryan M. Utz^1,* and Melanie N. Fetsko¹

¹Falk School of Sustainability, Chatham University, 6035 Ridge Road, Gibsonia, PA, 15044. *Corresponding author.

Northeastern Naturalist, Volume 27, Issue 2 (2020): 299–308

Abstract
We conducted a limited survey to analyze the potential effects of thick understory patches of Berberis thunbergii (Japanese Barberry), an invasive shrub, on forest-dwelling salamanders. Our observational survey of 4 riparian streams was aimed at addressing the hypothesis that Japanese Barberry would negatively affect salamander populations due to detrimental impacts on soil properties and native vegetation. We placed cover boards along the riparian zones of 2 streams that were heavily invaded and 2 that were sporadically invaded by Japanese Barberry in a western Pennsylvanian suburban deciduous forest. The following year, we surveyed each coverboard on 3 occasions to quantify amphibian abundance and diversity. We identified specimens to species whenever possible and quantified Japanese Barberry invasion intensity by estimating aboveground biomass. Results suggest salamander abundance was unaffected by the presence of Japanese Barberry. Species composition differed between invaded and uninvaded habitat, with more Desmognathus spp. salamanders dominating uninvaded sites, though data limitations prevented rigorous comparisons of community-scale differences. Our limited data are unable to determine if Japanese Barberry invasions are associated with indirect effects on salamander populations. However, the lack of any measurable effect on salamander abundance suggests that Japanese Barberry does not induce a strong direct effect on these species.

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