Effects Of Timber Harvest On Survival And Movement Of Stream Salamanders In A Managed Forest Landscape

With escalating anthropogenic alteration of landscapes worldwide, managed forests are increasingly important as providers of ecosystem services and wildlife habitat. Therefore, it is crucial to maintain a balance between producing forest products and biodiversity conservation. Several studies have reported negative effects of forest management on terrestrial plethodontid salamanders, but fewer have focused on stream-dwelling species or evaluated mechanisms for shifts in their abundance (e.g., mortality vs. movement). We used a before-after-control-impact design to examine the effects of clear-cut harvesting on a semi-aquatic stream-breeding salamander endemic to the Ouachita Mountains, Desmognathus brimleyorum. We conducted a three-year capture-mark-recapture (CMR) study at three streams within a managed pine (Pinus spp.) landscape in west-central Arkansas, USA. Loblolly pine (Pinus taeda) stands surrounding two of the streams were clear-cut (leaving a 14-21 m wide forested buffer on each side of the stream) midway through the study; the third stream served as a control site and remained unharvested. We estimated apparent survival using open CMR models and compared salamander movement over time and between harvested and control streams. Overall, our models revealed seasonal and temporal variation in salamander survival and abundance, but little evidence for strong immediate effects of timber harvesting on post-metamorphic salamanders within two years postharvest. However, there was increased salamander movement at sites where forest harvest occurred. Our results suggest that streamside buffers of at least 14-28 m on either side of a stream are effective for minimizing immediate effects of forestry activities on juvenile and adult stream-dwelling salamanders, when timber harvest occurs in the winter months. These results will inform management decisions aimed at conserving biodiversity and ecosystem integrity in managed forest landscapes while also filling a critical gap in the knowledge of stream salamander demographic parameters.