RESULTS AND DISCUSSION 

 Vegetation 



Tree density, including all age classes, varied from 125 

 to 138 stems per acre (309 to 342 stems per ha) on bird 

 study plots (cutting units) before logging (table 1). Trees 

 remaining after logging, mostly pole-sized and clumped 

 in distribution, ranged from 73 to 94 stems per acre (180 

 to 231 stems per ha). Few snag (dead) trees remained 

 after logging. Prelogging stand basal area on the cutting 

 units was 90 and 117 ft 2 per acre (20.7 and 26.8 m 2 per 

 ha); residual basal area was 22 and 24 ft 2 per acre (5.1 

 and 5.5 m 2 per ha). Volume of timber removed by 

 logging averaged 3,072 ft 3 per acre (215 m 3 per ha). This 

 represents a reduction of 78 percent in basal area and 95 

 percent in stand volume. 



Shrubs were the dominant feature of the understory 

 layer (table 1). Shrub canopy cover values, high before 

 logging, were reduced after logging and slash burning. 

 Both pre- and postlogging shrub canopy cover and vol- 

 ume were dominated by ninebark and white spiraea. 

 Grass and grasslike species, particularly pinegrass 

 (Calamagrostis rubescens), showed increases in cover 

 2 years after logging. Annuals, mostly littleflower 

 collinsia (Collinsia parviflora), increased. Shrubs and 

 herbs had a combined average canopy cover of 93 

 percent before logging and 76 percent 2 years after 

 logging. 



Breeding Birds, Unlogged Forest 



The density of breeding birds occupying the unlogged 

 forest ranged from 189 to 214 pairs per 100 acres 

 (40.5 ha) on the different plots during the 4-year study 

 (table 2). From 18 to 22 species were territorial. The 

 most abundant species, each making up more than 5 

 percent of the breeding bird community and collectively 

 accounting for 70 percent, were: 



Swainson's thrush 



western tanager 



dark-eyed junco 



red-breasted nuthatch 



chipping sparrow 



Empidonax flycatcher 



mountain chickadee 



MacGillivray's warbler 



(Scientific names are in table 2.) 

 Other common birds in the unlogged forest were: 



yellow-rumped warbler 



calliope hummingbird 



solitary vireo 



American robin 



brown creeper 



Cassin's finch 



hairy woodpecker 



Numerically, hole-nesting species made up 22 percent of 

 the breeding bird community. These were: 



northern flicker 

 hairy woodpecker 

 white-headed woodpecker 

 mountain chickadee 

 white-breasted nuthatch 

 red-breasted nuthatch 

 brown creeper 



When expressed as standing crop biomass, Swainson's 

 thrush was the predominant species, followed by the 

 western tanager, American robin, northern flicker, dark- 

 eyed junco, hairy woodpecker, and chipping sparrow. 

 Those seven species comprised 68 percent of the 

 standing crop biomass of the breeding birds. Total 

 standing crop biomass on unlogged study plots ranged 

 from 81 to 89 grams per acre (199 to 219 grams per ha). 



In addition to the 35 breeding bird species listed in 

 table 2, others commonly observed on or flying above 

 the study plots were: 



sharp-shinned hawk (Accipiter striatus) 

 northern goshawk (Accipiter gentilis) 

 red-tailed hawk (Buteo jamaicensis) 

 American kestrel (Falco sparverius) 

 spruce grouse (Dendragapus canadensis) 

 ruffed grouse (Bonasa umbellus) 

 gray jay (Perisoreus canadensis) 

 common raven (Corvus corax) 

 red crossbill (Loxia curvirostra) 



Other species observed less frequently on the study 

 plots included: 



turkey vulture (Cathartes aura) 



Cooper's hawk (Accipiter cooperii) 



golden eagle (Aquila chrysaetos) 



blue grouse (Dendragapus obscurus) 



mourning dove (Zenaida macroura) 



great horned owl (Bubo virginianus) 



northern pygmy owl (Glaucidium gnoma) 



rufous hummingbird (Selasphorus rufus) 



Williamson's sapsucker (Sphyrapicus thyroideus) 



downy woodpecker (Picoides pubescens) 



three-toed woodpecker (Picoides tridactylus) 



pileated woodpecker (Dryocopus pileatus) 



Steller's jay (Cyanocitta stelleri) 



Clark's nutcracker (Nucifraga columbiana) 



varied thrush (Ixoreus naevius) 



lazuli bunting (Passerina amoena) 



song sparrow (Melospiza melodia) 



brown-headed cowbird (Molothrus ater) 



pine grosbeak (Pinicola enucleator) 



evening grosbeak (Coccothraustes uespertinus) 



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