Biotic And Abiotic Factors Influencing Headwater Stream Organisms In The Southern Appalachians

The roles of biotic and abiotic factors in ecological and evolutionary phenomena are well-understood, however, few investigations have focused on these interactions involving morphologically dissimilar taxa. My research aimed to determine whether interactions were strong among morphologically dissimilar species with widely overlapping assemblages in southern Appalachian streams and if environmental conditions influenced the strength of these interactions. First, I conducted field surveys across headwater streams to estimate the occupancy probabilities and body condition of salamanders in response to the presence of morphologically dissimilar taxa and habitat variables. Second, I used in situ and ex situ methods to identify the potential abiotic and biotic factors that influence the spatial patterns associated with body condition and refuge use for stream salamanders and crayfish. My experiment aimed to determine if body condition, refuge use, cohabitation, and survival are influenced by refuge density and the presence of interspecifics. Field surveys involved examining the influence of habitat characteristics on interspecific cohabitation between salamanders and crayfish. Overall, conclusions from my thesis imply that stream salamanders and crayfish may simply coexist. Additionally, fish occurrence is likely influenced by slope and their presence can negatively affect the body condition of salamanders, thereby potentially driving salamander assemblages and distributions.