Responses of stream-breeding amphibians to riparian buffers in headwater streams: Ameliorating the effects of regeneration harvest

This study focused on steep (>10°) headwater streams in a volcanic geologic region in southwestern Washington. The presence and abundance of Rhyacotriton cascadae, Ascaphus truei, and Dicamptodon spp. (D. copei and D. tenebrosus) were assessed in four treatment types (unbuffered (clearcuts), buffered (12 to 23 m wide), second-growth (35 to 50 years old stands), and unmanaged (not previously logged)). No difference among treatments for R. cascadae or Dicamptodon spp. presence was found. R. cascadae abundance did not differ statistically between buffered and second-growth streams or between buffered and unbuffered streams. R. cascadae densities did differ between second-growth and unbuffered streams and were lower in all managed streams compared to unmanaged. A. truei presence was different among treatments. Abundance of A. truei and Dicamptodon spp. did not differ among treatments. R. cascadae was present less frequently in streams with > 35.5 consecutive hours of water temperatures above 13.5°C.