Raw count data from repeated surveys of a guild of Plethodon salamanders in an old-growth forest in southeastern Kentucky 2016, with GIS and in situ environmental data

Woodland salamanders are among the most abundant vertebrate animals in
temperate deciduous forests of eastern North America. Because of their
abundance, woodland salamanders are responsible for the transformation
of nutrients and translocation of energy between highly disparate
levels of trophic organization: detrital food webs and high-order
predators. However, the spatial extent of woodland salamanders’ role
in the ecosystem is likely contingent upon the distribution of their
biomass throughout the forest. We sought to determine if natural
environmental gradients influence the fine-scale distribution and
density of Southern Ravine Salamanders (Plethodon richmondi) and
Cumberland Plateau Salamanders (P. kentucki). We addressed this
objective by constructing occupancy, co-occurrence, and abundance
models from temporally-replicated surveys within an old-growth forest
in the Cumberland Plateau region of Kentucky occurring in the Fall of
2016. We found that Plethodon richmondi had a more restricted
fine-scale distribution than P. kentucki (mean occupancy probability =
0.737) and exhibited variable density, from less than 250 to greater
than 1000 individuals per hectare, associated with increased soil
moisture and reduced solar exposure due to slope face. While more
ubiquitously distributed (mean occupancy probability = 0.95), P.
kentucki density varied from less than 400 to greater than 1000
individuals per hectare and was inversely related to increased solar
exposure from canopy disturbance and landscape convexity. Our data
suggest co-occurrence patterns of P. richmondi and P. kentucki are
influenced primarily by abiotic conditions within the forest, and that
populations likely occur independently and without evidence of biotic
interaction. Given the critical role that woodland salamanders play in
the maintenance of forest health, regions that support large
populations of woodland salamanders, such as those highlighted in this
study—mesic forest stands on north-to-east facing slopes with dense
canopy and abundant natural cover, may provide enhanced ecosystem
services and support the stability of the total forest.