Landscape management using historical fire regimes: Blue River, Oregon

Landscapes administered for timber production by the U.S. Forest Service in the Pacific Northwest in the 1950s-1980s were managed with dispersed patch clear-cutting, and then briefly in the late 1980s with aggregated patch cl ear-cutting. In the late 1990s, use of historical landscape patterns and di sturbance regimes as a guide for landscape management has emerged as an alt ernative to the static reserves and standard matrix prescriptions in the No rthwest Forest Plan. Use of historical information to guide management reco gnizes the dynamic and variable character of the landscape and may offer an improved ability to meet ecosystem management objectives. We describe a landscape management plan based in part on interpretations of historical disturbance regimes. The plan contains a reserve system and oth er landscape areas where three distinct types of timber harvest are prescri bed. Timber harvest prescriptions approximate the frequency, severity, and spatial extent of past fires. Future harvest blacks are mapped and used to project forest patterns 200 yr forward and to map resulting landscape struc ture. This plan is compared with an alternative plan for the same area based on t he extensive reserves and prescriptions for matrix lands in the Northwest F orest Plan. The management approach based on historical patterns produced m ore late-successional habitat (71% vs. 59%), more overstory structure in yo ung stands (overstory canopy cover of 15-50% vs. 15%), larger patches (mean patch size of 48 vs. 26 ha), and less edge between young and old forest (e dge density of 19 vs. 37 m/ha). While landscape structures resulting from b oth plans are historically unprecedented, we feel that landscape management plans incorporating key aspects of ecosystem history and variability may p ose less risk to native species and ecological processes.