Forest harvest is one of the dominant land uses in the Pacific Northwest. Harvest effects on stream amphibians are highly variable and can differ based on harvest intensity and distance from the harvest site. Researchers conducted an experiment in the Trask River watershed in Oregon to investigate the impacts of harvest practices on larval coastal tailed frogs, coastal giant salamanders, and Columbia torrent salamanders in stream sections adjacent to and 150 meters downstream from clearcuts of varying intensities. At some of the sites, 12-meter buffers of trees were left between the clearcut and stream. Other sites had smaller, variable-width buffers. For all species, occupancy was lowest in streams adjacent to clearcuts with variable-width buffers. The coastal giant salamander was the only species with reduced occupancy and abundance in downstream areas. Preserving larger buffers of trees between clearcuts and streams did not always reduce the negative impacts on amphibians. These results confirm that clearcut logging can have negative effects on stream amphibians at different spatial extents. The potential for cumulative downstream impacts is an important forest management consideration.  

Duarte, A., Chelgren, N.D., Rowe, J.C., Pearl, C.A., Johnson, S.L., and Adams, M.J., 2023, Adjacent and downstream effects of timber harvest on larval headwater stream amphibians in the Oregon Coast Range: Forest Ecology and Management, v. 545, 121289. https://doi.org/10.1016/j.foreco.2023.121289