Responses of Birds and Small 

 Mammals to Single-Tree 

 Selection Logging in Idaho 



Dean E. Medin 

 Gordon D. Booth 



INTRODUCTION 



Alterations in the structure of forest vegetation caused 

 by logging produce changes in the organization of associ- 

 ated bird and small mammal communities. Population 

 responses to logging depend on the cutting methods used 

 and the degree to which stands are altered. The effects of 

 clearcut logging have been extensively reviewed (Blake 

 1982; Halvorson 1982; Martell 1983; Medin 1985; Scott 

 and others 1982; Szaro and Balda 1979). Populations of 

 some birds and small mammals may increase while others 

 decline in postclearcut environments (Medin 1985, 1986). 



Few studies have been conducted on the effects of other 

 methods of tree removal (but see Campbell and Clark 

 1980; Franzreb and Ohmart 1978; Scott and Gottfried 

 1983). Alternative cutting methods include the selection 

 method where the oldest or largest trees in a stand are 

 removed either singly (single-tree selection) or in groups 

 (group selection) without completely clearing the entire 

 stand (Smith 1962). 



This study, conducted from 1975 to 1979, examined 

 short-term changes in the composition and abundance of 

 small mammals and breeding birds following single-tree 

 selection logging in a Douglas-fir (Pseudotsuga menziesii) 

 forest in west-central Idaho. Data were collected as part 

 of a study of the environmental effects of logging and 

 associated road construction in the Idaho batholith, a 

 large region (16,000 mi^) characterized by steep topogra- 

 phy and shallow, erodible soils (Megahem 1983). Selection 

 cutting is one of several timber harvesting methods cur- 

 rently being evaluated for their multiple effects on the 

 forest ecosystem. 



Common and scientific names of birds and small mam- 

 mals referred to in this paper are listed in appendix I. 



STUDY AREA 



The study was conducted on two experimental water- 

 sheds of 319 acres (SC-3) and 67 acres (SC-7) in the Silver 

 Creek drainage, a tributary of the Middle Fork of the 

 Payette River in Valley County, ID. These third-order 

 watersheds range in elevation from 4,600 to 6,500 ft and 

 are representative of forested drainages found in midele- 

 vation, nonglaciated landscapes of the Idaho batholith. 

 Slopes are steep and dissected. Watershed SC-3 drains to 

 the southeast; watershed SC-7 drains to the northwest. 

 The area has a Mediterranean climate with hot, dry 



summers and cool, moist winters. Annual precipitation 

 averages 39 inches, with about 65 percent falling as snow 

 (Megahan and others 1983). High-intensity convective 

 rainstorms are common during the summer months. 



Douglas-fir and ponderosa pine (Pinus ponderosa) are 

 the dominant overstory trees, with scattered stands of 

 grand fir {Abies grandis), lodgepole pine {Pinus contorta), 

 and Engelmann spruce {Picea engelmannii). Mallow 

 ninebark {Physocarpus malvaceous), and white spiraea 

 {Spiraea betulifolia) normally dominate the shrubby 

 undergrowth. Rocky Mountain maple {Acer glabrum), 

 snowberry {Symphoricarpos spp.), common chokecherry 

 (Prunus virginiana), blue huckleberry {Vaccinium globu- 

 lare), and western serviceberry {Amelanchier alnifolia) 

 are often present. Willows {Salix spp.) and alders {Alnus 

 spp.) are locally abundant, especially on the north-facing 

 watershed. Many forbs and graminoids occupy the 

 ground layer. 



Two main habitat types (Steele and others 1981) occur: 

 Douglas-fir/ninebark, ponderosa pine phase, and Douglas- 

 fir/white spiraea, ponderosa pine phase. The experimen- 

 tal watersheds also include elements of the grand fir/blue 

 huckleberry and subalpine fir {Abies lasiocarpa)/h\ue 

 huckleberry habitat types (Ryker 1973). 



LOGGING PROCEDURE 



Selected trees in watershed SC-7 were marked and 

 felled within a defined cutting unit boundary. Watershed 

 SC-3 served as a nearby unlogged control. The logged 

 cutting unit was irregularly elongate and followed the 

 topographic boundary of the experimental watershed. 

 Uncut buffer zones bordered stream channels and aver- 

 aged 50 ft to first-order or second-order stream channels, 

 and 100 ft to the third-order (main) stream channel. Logs 

 were yarded by helicopter to minimize site damage, a 

 common practice on steep slopes in the Idaho batholith. 

 Logging slash was lopped and scattered. 



A prelogging timber volume on the cutting unit of 

 17,087 bd ft per acre was reduced 29 percent by the 

 selection-cut logging. There were 47 trees (>9 inches 

 diameter at breast height) per acre on the watershed 

 before cutting; 38 trees per acre remained after logging 

 (McKenzie 1987). The cutting was originally targeted to 

 reduce prelogging stand volume on the experimental 

 watershed by 30 to 35 percent. Logging began in 

 September and was completed in October 1976. 



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