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INITIAL RESPONSE OF FLOODPLAIN RE-CONNECTION AND WOOD ADDITION TO THE FISH COMMUNITY IN THE LITTLE ARNOT RUN WATERSHED, ALLEGHENY NATIONAL FOREST.

    Delp, Lydia, Commonwealth University of Pennsylvania – Lock Haven, 401 N Fairview St, Lock Haven, PA 17745, lgd7371@lockhaven.edu, Seiler, Steve, Commonwealth University of Pennsylvania – Lock Haven, 401 N Fairview St, Lock Haven, PA 17745, sseiler@commonwealthu.edu, Bechtold, Heather, Commonwealth University of Pennsylvania – Lock Haven, 401 N Fairview St, Lock Haven, PA 17745, hab206@commonwealthu.edu.

    The Allegheny National Forest occupies over 500,000 square miles in northwestern PA and has been extensively influenced by human activity including timber harvest, resource extraction, and other impacts. Road building activities to support resource extraction has often left streams that are constrained by berms and disconnected from their floodplain (channelized). Historic timber practices in some watersheds have left even-aged trees along the riparian corridor that have not contributed wood to the stream channel and toward instream fish habitat. Since 2019, multiple partners from Federal and State Agencies have been cooperating to reconnect the channelized portion of Little Arnot Run to its floodplain and to increase the amount of wood in the stream channel by careful installation of tree bundles in lower portions of the watershed and widescale, directional felling of riparian trees throughout the rest of the watershed. Floodplain reconnection in lower sites on Little Arnot Run was completed in August 2021 and directional felling of trees throughout the watershed was completed in early 2022. Here, we present fish community data from Little Arnot Run sites across four years spanning pre-restoration efforts (= 2 years pre-restoration and 2 years of post-restoration) and compare these data with the fish community from Cherry Run, a nearby watershed without restoration activity that serves as a control watershed. We conducted triple pass electrofishing surveys in late July-early August of each year to estimate the composition and biomass of the fish community at two locations in each watershed, one location near the downstream confluence and one location closer to the headwaters. We did not find strong trends in species richness or fish community diversity following restoration. Variation in the number and biomass of brook trout (Salvelinus fontinalis), and in the whole fish community, appears to be highly influenced by baseflow conditions. After correcting for the area sampled, fish biomass at locations in Little Arnot Run may be trending upward when compared to reference sites in Cherry Run. Continued monitoring is planned to verify any longer-term influences of this restoration work on the fish community.

    watershed restoration, fish community, wood addition