Contemporary Silvicultural Practices in the Western Portion of the Pacific Northwest, USA

Abstract The western portion of the Pacific Northwest (PNW) has some of the most productive and iconic forests of the United States. Management of these forests has changed dramatically over the past three decades, driven by the primary objectives and constraints associated with major forest landowner groups. Key changes include 1) increased focus on the establishment phase and a reduction in intermediate treatments for ownerships practicing intensive management (e.g., forest industry), 2) an increase in the use of variable retention harvesting on state, Bureau of Land Management, and tribal managed lands, and 3) and a shift to almost exclusive use of thinning on National Forest System lands. Most silvicultural activity is focused on Douglas-fir on privately owned timberlands despite federal ownerships comprising more than half of all timberland in the region. Regeneration is primarily accomplished via planting using both genetically improved and wild-collected seed depending on species and ownership. Increased fire occurrence and severity have given rise to a broad class of treatments related to fuels reduction and thinning to increase resiliency, which is likely to continue to expand. Future changes in practice will be driven by evolving objectives of major forest landowner groups, but we anticipate increased focus on the establishment phase across all groups. Reduced investment in silviculture research and a trend towards standardized silvicultural prescriptions are key challenges to future innovation in the region at a time when the need for innovation to maintain forests and the benefits they provide has never been greater.