Estimating the impacts of harvest distribution on road-building and snag abundance

Various patterns of harvest in forests influence the length of road and number of stream crossings required. Snags are removed directly by harvesting, but they are also removed along road and opening edges to ensure worker safety. To assess the potential impacts of rate of harvest and pattern of harvest in an old-forest-dominated montane landscape, we developed a spatially explicit landscape dynamics model, which includes submodels for snag removal, harvesting activities, and access management. The model assesses the amount of new road construction and number of streams crossed by new roads, as well as changes in snag density and configuration across the landscape over a time horizon of several decades, in response to various harvesting patterns. We estimated that a dispersed 40-ha cutblock harvest pattern required about one-third more kilometres of new road over a 50-year period and removal of up to 70% more snags per hectare of harvest for safety purposes, compared with a harvest pattern based on natura...