Hydrologic response to and recovery from differing silvicultural systems in a deciduous forest landscape with seasonal snow cover

Abstract Hydrologicalconsequences of alternative harvestingstrategies in deciduousforest landscapes with seasonal snow cover have received relatively little attention. Most forest harvestingexperiments in landscapes with seasonal snow cover have focused on clearcuttingin coniferous forests. Few have examined alternative strategies such as selection or shelterwood cuttingin deciduousstands whose hydrologicresponses to harvestingmay differ from those of conifers. This study presents results from a 31-year examination of hydrologicalresponse to and recovery from alternative harvestingstrategies in a deciduousforest landscape with seasonal snow cover in central Ontario, Canada. A quantitative means of assessing hydrologicrecovery to harvestingis also developed. Clearcuttingresulted in increased water year(WY) runoff. This was accompanied by increased runoff in all seasons, with greatest relative increases in Summer. Direct runoff and baseflowfrom treatment catchments generally increased following harvesting, although annual peak streamflowdid not. Largest increases in WY runoff and seasonal runoff as well as direct runoff and baseflowgenerally occurred in the selection harvestcatchment, likely as a result of interception of hillslope runoff by a forest access road and redirection to the stream channel. Hydrologicrecovery appeared to begin towards the end of the experimental period for several streamflowmetrics but was incomplete for all harvestingstrategies 15 years after harvesting. Geochemical tracing indicated that harvestingenhanced the relative importance of surface and near-surface water pathways on catchment slopes for all treatments, with the clearcutcatchment showing the most pronounced and prolonged response. Such insights into water partitioning between flow pathways may assist assessments of the ecological and biogeochemical consequences of forest disturbance.