The Un-frog-ettable Microhabitats of Northeastern Amphibians: Rural to Urban Gradients

Abstract

Amphibians have been the subject of global decline for decades. There are many factors contributing to their decline, one of which is urbanization and the side effects resulting from it, such as habitat fragmentation and pollution. Habitat fragmentation resulting from land-use changes such as silviculture, agriculture, and urbanization impact forest structure and resource availability for herpetofauna. Notably, factors like soil pH, moisture, as well as the abundance of coarse woody debris (CWD) and rocky microhabitats, can undergo significant changes with these stand and landscape-level disturbances. In Fall 2024, we examined four sites along a landcover gradient (e.g., Urban- Rugar Woods, Agriculture- Riley Brook, and Forested-Control and Silviculture- Paul Smiths VIC). We found that the site with the least amount of disturbance/management and farthest from urban sprawl had the highest amphibian abundance and diversity, with 5 different species represented over a total of 47 individuals. Site-specific unique species include northern dusky salamanders (Desmognathus fuscus) at the agriculture-Riley Brook, an American toad (Bufo a. americanus) at the Forest-Paul Smiths silviculture, and a four-toed salamander (Hemidactylium scutatum) at the Forest-Paul Smiths control site. Red-backed salamanders (Plethodon cinereus) were the most abundant species found, and were observed in all sites, excepting for agriculture. Due to the abundance of red-backed salamanders, we were able to compare differences in morphological data, the lengths (cm) and weights (g). Although there was no significant difference in length, urban red-backed salamanders were heavier than at other sites. We found no significant difference in microhabitat temperatures across site or type (e.g., CWD, rock, grass), but amphibians preferred log cover to any other microhabitat in all sites but Rugar Woods. We calculated the Sorensen similarity index to assess species composition similarities and further examine the impact of environmental changes on biodiversity across sites. With the addition of this research, we aim to gain a deeper understanding of the habitat preferences, site characteristics and requirements of amphibians, information that is crucial for guiding effective conservation efforts and mitigating biodiversity loss.