Silviculture For Multiple Objectives In The Douglas Fir Region

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.

These guidelines are a correlation of many guidelines for uneven-aged stand management already in place in many forest districts and regions in British Columbia. The guidelines include a statement of principles, standards, and procedures and information on applicable stands; stratification; pre-harvest cruise and silviculture prescription; cutting permits; monetary assessments; pre-work guidance for harvesters; harvest monitoring; post-harvest assessments; stocking surveys; free growing surveys; and reporting.

A silviculture prescription is a site-specific plan that describes the forest management objectives for an area. A prescription prescribes the method for harvesting the existing forest stand and a series of silviculture treatments that will be carried out to establish a free growing crop of trees in a manner that accommodates other resource values as identified. This document describes the contents of what silviculture prescription plans must contain in British Columbia to comply with the Forest Practices Code. It includes information on general requirements for the plan as well as specific requirements for tenure identification, management objectives, degree of consistency with other plans, ecological and resource information, forest health assessment and prescription, soil conservation, actions to accommodate forest resource values, silvicultural systems, harvesting, fire hazard abatement, silviculture treatments, stocking standards, and mapping.