RESULTS OF REGENERATION CUTTING IN A SPRUCE -ALPINE FIR STAND 



A. L. Roe and G. M. Dejarnette 

 INTRODUCTION 



Development of the Engelmann spruce (Picea engelmannii Parry) -subalpine fir (Abies 

 lasiocarpa (Hook) Nutt.) forest in the northern Rocky Mountains has posed many problems for 

 the forest manager. Because the forest grows at high elevations and is costly to develop, it 

 presents many silvicultural problems, particularly in designing cutting practices and in work- 

 ing out the best regeneration process. A low level of utilization, until recent years, meant 

 limited experience in spruce management. Recently, however, forest managers have begun to 

 utilize Engelmann spruce to supplement the short supply of other quality species , and also to 

 control insect epidemics that threaten the overmature stands. 



One of the principal problems in developing the spruce type is to convert dominant old- 

 growth stands to stands comprised of young growing stock. Harvest cutting and natural 

 regeneration present one solution. One such cutting was attempted in northern Idaho from 1916 

 through 1925. Observations of this area were made in 1921, 1929, and 1954; this paper reports 

 the establishment and development of regeneration and changes in the residual stand. 



STUDY AREA 



The study area is located in Spruce Creek on the Kaniksu National Forest in northern 

 Idaho at an elevation ranging from about 4,200 to 6,000 feet. The stand varied from a white 

 pine type on the slopes at the lower end to a pure spruce -fir stand on the upper slopes and in 

 the basin at the head of the stream (fig. 1). The stand on the slopes was composed of a mixture 

 of species with a predominance of Engelmann spruce but with white pine in the mixture where 

 the white pine and Engelmann spruce -subalpine fir types merged. The basin supported a nearly 

 pure spruce -subalpine fir stand. Age of the residual trees ranged from 118 to 140 years. The 

 whole area can be classified as a Picea-abies/menziesia ecological heibitat type.^ 



Logging started in the summer of 1916 and was completed bythe end of 1925. Area logged 

 each year varied from a high of 133 acres in 1917 to a low of 43 acres in 1918. Area cut in the 

 other years ranged between these extremes, and a total of about 800 acres was cut over. The 

 total yield amounted to approximately 23.5 million board feet. The volume removed was com- 

 prised of 56 percent spruce, 31 percent subalpine fir, 5 percent western white pine, and 8 

 percent mixed western larch, Douglas -fir, and lodgepole pine. 



Except for a tract of 30 acres, the total area was clearcut, leaving seed -tree groups, 

 strips, and blocks. On the clearcut area, seed-tree groups were composed of 15 to 20 trees 

 each; strips were 1 chain wide and of different lengths; and two blocks were of 1-acre size. 

 The 30-acre tract was partially cut, reserving 27 percent of the original volume. Locations of 

 the partial cutting, seed-tree groups, strips, and blocks are shown in figure 1. 



Daubenmire, R. Forest vegetation in northern Idaho and adjacent Washington and its 

 bearing oji concepts of vegetation classification. Ecol. Monog. 22:301-330, illus. 1952. 



