Silvicultural knowledge & practice have been evolving in the Pacific Northwest for nearly a century. This report on research & management activities includes: foundations & definitions; historical development of silviculture in the Douglas-Fir Region; forest conditions, stand development, & management goals; generation methods; shaping development of young natural stands & plantations; harvesting considerations; providing diverse structures & habitats; maintaining site productivity; damaging agents & forest health; management choices; information needs; policy questions; references; management scenarios; & glossary.

Silvicultural practices in the Douglas-fir region evolved through a combination of formal research, observation, and practical experience of forest managers and silviculturists, and changing economic and social factors. This process began more than a century ago and still continues. It has had a great influence on the economic well-being of the region and on the present characteristics of the regions forests. This long history is unknown to most of the public, and much of it is unfamiliar to many natural resource specialists outside (and even within) the field of silviculture. We trace the history of how we got where we are today and the contribution of silvicultural research to the evolution of forest practices. We give special attention to the large body of information developed in the first half of the past century that is becoming increasingly unfamiliar to both operational foresters andperhaps more importantlyto those engaged in forestry research. We also discuss some current trends in silviculture and silviculture-related research.

This report describes the origin, design, establishment and measurement procedures and first results of a large long-term cooperative study comparing a number of widely different silvicultural regimes applied to young-growth Douglas-fir (Pseudotsuga menziesii) stands managed for multiple objectives. Regimes consist of (1) conventional clearcutting followed by intermediate thinning; (2) retention of reserve trees to create a two-aged stand; (3) small patch cuts dispersed within a thinned matrix, repeated at approximately 15-year intervals to create a mosaic of age classes; (4) group selection within a thinned matrix on an approximate 15-year cycle; (5) continued thinning on an extended rotation; and (6) an untreated control. Each of these regimes is on operationsize units (about 30 to 70 acres each). Output variables to be evaluated include conventional timber growth and yield statistics, harvest costs, sale layout and administration costs, aesthetic effects and public acceptance, soil disturbance, bird populations, and economic aspects. Descriptive statistics and some initial results are presented for the first replicate, established in 1997-98.

We review 12 large-scale silviculture experiments (LSSEs) in western Washington and Oregon with which the Pacific Northwest Research Station of the USDA Forest Service is substantially involved. We compiled and arrayed information about the LSSEs as a series of matrices in a relational database, which is included on the compact disc published with this report and available online at http://www.fs.fed.us/pnw/research/lsse. The LSSEs are both spatially and temporally large scale, with experimental treatment units between 5 and 100 acres and proposed study durations of 20 to 200 years. A defining characteristic of the LSSEs is that a broad range of response variables are measured to characterize the response of forest ecosystems to experimental treatments. We discuss the general value and limitations of the LSSEs and highlight some possible roles that can be played by the LSSEs in addressing management issues emerging at the beginning of the 21st century.