Patterns of species distributions and abundance are driven by a combination of species abiotic niches and biotic interactions between members of a community. Joint-species distribution models extend traditional modeling of occurrence or abundance to quantify species corelationships that may result from interspecific interactions. In the southern Appalachian Mountains, stream-associated salamander communities are thought to be structured by competitive and predatory interactions; therefore, spatial patterns in occurrence and abundance and temporal patterns in activity may reflect species associations. To evaluate the role of interspecific interactions in salamander community occurrence and abundance patterns, we conducted repeated point-count and leaf-bag surveys for adult and larval communities, respectively. We estimated adult and larval community occurrence and abundance by using the hierarchical modeling of species communities framework to identify the extent to which residual co-occurrence and correlation in abundance was present within these communities. For both adult and larval communities, we found no evidence that residual co-occurrence or correlation in abundance was present. Instead, results indicated that environmental covariates characterizing both plot- and landscape-level habitat conditions were responsible for observed patterns. In addition, we found no evidence for temporal niche partitioning, suggesting competition does not play a significant role in inter- or intraday activity patterns. Our results contrast with the accepted paradigm that extant biotic interactions drive community composition among stream-associated salamanders. Instead, our findings suggest that the effects of biotic interactions are not evident at the spatial or temporal scales associated with occurrence or abundance.

You do not currently have access to this content.