Silvicultural options for young-growth Douglas-fir forests: the Capitol Forest study—establishment and first results.

Descriptive statistics and some initial results are presented for an operation-scale study being conducted by Pacific Northwest Research Station and the Washington Department of Natural Resources in cooperation with the University of Washington and University of Idaho. The study compares a number of widely different silvicultural regimes applied to young-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in western Washington managed for multiple objectives. The first replicate was established in 1997-98. A second replicate was harvested in the summer of 2002 and a third is planned for 2004. The regimes compared are (1) conventional clearcutting, (2) retention of reserve trees to create a two-age 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) repeated thinning on an extended rotation, and (6) an extended rotation on an untreated control. Variables to be evaluated include timber growth and yield, regeneration, harvest costs, sale layout and administration costs, public acceptance, soil disturbance, bird populations, and economics. We have no growth data as yet, but some preliminary results are available for other aspects of the study. • Windfall losses in the first 4 years after establishment were comparatively small, occurring mainly in the two-age and patch cut units and around the margins of the clearcut unit. • Sale preparation costs were lowest for the clearcut and highest for group selection. Costs per acre for the repeated thinning, two-age, and patch cut regimes were similar. Cost per unit of volume decreased, however, as volume removed increased. A major element in costs was cost of marking, which could be considerably reduced in the future. • Harvesting was with ground-based equipment. The clearcut unit had the lowest harvesting cost per thousand board feet. The two-age regime was about 9 percent higher, the patch cut was 17 percent higher, group selection 16 percent higher, and thinning 24 percent higher than the clearcut cost. • Soil surface disturbance was evaluated on a series of transects. In general, as removal intensity increased the percentage of disturbed area increased (22.5 to 32.2 percent). There was little rutting on any of the units. • Photographs of the several treatments were used in a preference survey administered to several user groups. All groups showed a preference for " green natural appearance , " and foresters tended to be …