Search

The appropriate management of streamside forests and use of riparian strips is poorly resolved for many systems because of a lack of understanding of the extent to which riparian forests function as environmental buffers for aquatic species versus core (essential) habitat for semi-aquatic and terrestrial species. We studied streamside forests in western North Carolina and eastern Tennessee, USA, to help delineate their functional value for plethodontid salamanders. We established 30 m × 40 m plots at 17 sites (823–1716 m in elevation) in unmanaged forests with closed canopies. Plots contained a portion of a seep or first-order stream along one edge and typically extended 36–38 m into the adjoining forest. We examined use of stream and streamside habitats based on captures during area-constrained searches of cover objects. We observed 6423 plethodontid salamanders belonging to 7 terrestrial-breeding and 12 aquatic-breeding species. Terrestrial-breeders (primarily Plethodon spp.) comprised 37% of terrestrial specimens and were more abundant at higher elevations. Aquatic-breeders (primarily Desmognathus spp.) increased their proportionate use of terrestrial habitat, but declined in overall abundance with elevation. Catches of aquatic-breeders were greatest within 8 m of aquatic habitats (49% of total terrestrial catch of aquatic-breeders), particularly at low elevation sites. The terrestrial zone provided core habitat for one terrestrial-breeder ( D. wrighti ) and six semi-aquatic species ( Desmognathus spp., Gyrinophilus porphyriticus and Eurycea wilderae ) that were broadly distributed throughout plots, and acted as an aquatic buffer for four highly aquatic species ( Desmognathus spp.). The remaining species were terrestrial-breeders ( Plethodon spp.) that were evenly distributed across plots, suggesting that riparian strips would function as important source populations for recolonization following timbering on adjoining land. Because of the vulnerability of plethodontid salamanders to edge effects, effective management of southern Appalachian streamside habitats may require the addition of a terrestrial buffer to protect terrestrial core habitat that immediately adjoins streams and seeps.

We examined the effects of timber harvesting on southern Appalachian salamander communities in a managed watershed in Pisgah National Forest, western North Carolina, USA. Salamander abundance and species richness were lowest in very young stands and highest in stands more than 120 years old. Comparisons of recent clearcuts less than 5 years old with mature stands more than 80 years old suggest that terrestrial salamanders are completely eliminated or reduced to very low numbers when mature forests are clear cut. Comparisons of stand age categories further suggest that salamander abundance in local communities slowly increases for a century or more after stands are intensively harvested. We roughly estimate that logging during the last century by both the private and public sector has resulted in 1 70% decline in salamander numbers within the study area as a whole. Implementation of an ecosystem-management strategy which reverses the current trend of having landscapes dominated by early and mid-successional forests would help restore depleted populations to levels where salamanders better fulfill their ecological roles as forest-floor insectivores. Other management techniques that would benefit salamanders include leaving buffers along headwater streams, and using harvesting techniques which assure that the basic structure and function of forests remain intact following timbering operations.