TREATMENTS 



The THSA was initially harvested from 1942 to 

 1944, leaving three to five seed trees over 12 inches 

 (31 cm) d.b.h. per acre (0.4 ha) (Fredeking 1953). 

 The seed trees and trees that were unmerchantable 

 in the 1940's were removed in the winter of 1988-89 

 within partial-cut units, and more extensive over- 

 story removal occurred in the clearcut units. Based 

 on guidelines for the management of cavity-nesting 

 birds by McClelland and Frissell (1975), snags of all 

 species of trees, along with living paper birch, quak- 

 ing aspen, and black cottonwood, were retained in 

 the cutting units during the recent harvest 

 (figs. 3 and 4). 



The THSA was 650 acres (263 ha) and included 

 clearcut and partially cut units along with unlogged 

 forest (fig. 1). There were five clearcuts ranging 

 from 14 to 35 acres (6 to 14 ha). The largest partial- 

 cut unit was 70 acres (28 ha), and eight others ranged 

 between 5 and 40 acres (2 and 16 ha). Experimental 

 controls were provided by the unlogged forest of 

 330 acres (134 ha) within the THSA and the adjacent 

 837-acre (339-ha) CRNA. 



Slash piling and scarification of the units was 

 accomplished with a bulldozer in 1989. Most of the 

 slash piles were burned during the autumn of 1989, 

 and sites with slopes greater than 20 percent were 

 broadcast burned in September 1990. 



Figure 3 — Evidence of woodpecker foraging 

 surrounds a wildlife tree marker on a western 

 larch snag. The snag was retained for wildlife 

 use within a clearcut on the Terrace Hill sale 

 area. 



Figure 4 — Clearcut stand on the Terrace Hill sale area, 

 with western larch snags and living paper birch retained 

 for wildlife use. 



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