PRESENTATION ABSTRACT
Stand-level studies have shown partial cutting (typically 30–70% canopy retention) maintains habitat for many species using mature forest. We used simulation modelling to examine the potential magnitude of such benefits if a shift to 30% of harvest volume from clearcutting to partial cutting was implemented in the Nadina Forest District, in the context of mountain pine beetle attack, salvage harvesting, and climate change. We projected future landscape conditions by applying 140-year harvest trajectories from Timber Supply Review simulations to four retention scenarios: (1) “status quo” of no retention beyond conventional wildlife-tree-patch requirements; (2) retention of understorey conifers; (3) retention of 30–70% of live overstorey; and (4) both understorey and overstorey retention.
We then assessed the ability of projected landscapes to support wildlife species “profiles” representing territory size requirement and strength of association with mid- to old-seral forests. We focussed on species generally associated with mid- to old-seral forests and constrained in their use of space by territoriality (e.g., marten). For each landscape, we estimated the number and quality of potential territories, and dispersal connectivity among territories. We also projected mature-forest bird community similarity. Retention strategies led to substantive increases (10–38%) in long-term territory abundance and bird community similarity. Depending on species profile, overstorey retention had the greatest long-term effect: ~5–26% above status quo for territory abundance, and 0–7% with understorey retention alone. Connectivity differences were more equivocal. Increased territory abundance in turn made populations more resilient to increased future disturbance risk from changing climate.
