Geochemical response and benthic recolonization following a sensitive-clay landslide in a subarctic river

in deeper layers. By 11-16 months, these surface enrichments were leached or eroded downstream, indicating transient retention of landslide-derived trace elements. At 28 months, porewater Mn, Fe, sulfate and sulfide profiles exhibited redox zonation characteristic of reestablished diagenetic processes, coinciding with the reestablishment of a diverse benthic macroinvertebrate community. This study provides quantitative recovery timescales for a subarctic river system following landslide disturbance: <12 months for surface trace element export and 28 months for benthic recolonization. These recovery timescales are urgently needed as climate-driven increases in permafrost thaw and extreme precipitation intensify disturbance frequency across Arctic watersheds.