above a saturated subsoil in spring and winter. Bedding 

 concentrated nutrients in the planting row for more 

 effective utilization by the seedhng. In southern Illinois, 

 Gilmore and others (1968) found that bedding increased 

 growth of yellow-poplar planted on abandoned field sites 

 by enhancing organic matter levels. In New Zealand, 

 bedding a fiat, dry site increased soil nutrient levels and 

 resulted in faster early growth of Eucalyptus nitens 

 (Frederick and others 1984). Generally, soil bedding 

 enhanced upland planting sites by increasing nutrient 

 availability and moisture. 



In northern Idaho, and other parts of the Pacific 

 Northwest, much of the growing season is characterized 

 by low soil moisture and high evaporative demand, 

 which can markedly reduce the success of forest plant- 

 ings. Poor results have been documented with plantings 

 of Douglas-fir (Pseudotsuga menziesii var. glauca [Mirb.] 

 Franco) and western white pine (Pinus monticola Dougl. 

 ex D. Don) on clearcuts with low nutrient and moisture 

 levels (Duryea and Lavender 1982). Mounding surface 

 organic matter and mineral soil into planting beds 

 should increase storage of water and nutrients in most 

 forest soils, thus providing improved growth and seed- 

 ling survival. 



STUDY DESCRIPTION 



The objective of this study was to compare raised 

 planting beds with conventional site preparation treat- 

 ments in terms of the following soil physical properties: 

 bulk density, temperature, moisture, and organic matter 

 level. Studies were conducted on two productive habitat 

 types with distinctively different regeneration problems 

 in northern Idaho. These two sites, located at differing 

 elevations, provided a range of environmental conditions 

 for evaluating the effectiveness of bedding as a means of 

 ameliorating environmental hazards to seedling survival 

 in soils of the Intermountain West. A subsequent study 

 will monitor and report on the survival and growth rates 

 of seedlings planted on the various site treatments. 



SITE DESCRIPTION 



Two sites, located on the Priest River Experimental 

 Forest near Priest River, ID, were used in this study. 

 The Experimental Forest lies on the westward slope of a 

 spur of the Selkirk Mountains in northeastern Idaho. 



One site is located at an elevation of 715 m above sea 

 level on a flat bench adjoining the Priest River. It is the 

 warmer and drier of the two sites and has the longer 

 growing season. Burned in 1922, it had been used as an 

 area for studying the flammabiUty of forest fuels. It is 

 now occupied by grasses, forbs, and a few lodgepole pine 

 (Pinus contorta Dougl. ex Loud.). It is considered the 

 harsher of the two sites. The soil is classified as a 

 Springdale sandy loam (Inceptisols); however, the study 

 site has a silt loam texture. The habitat type was classi- 

 fied as Abies grandis/Symphoricarpos albus (Cooper and 

 others in press). Annual precipitation averages 83.8 cm, 

 with a mean annual temperature of 6.6 °C (Wellner 

 1976). 



Site 2 is near Observatory Point in the Canyon Creek 

 watershed at an elevation of 1 456 m above sea level. 



Slopes range from 10 to 35 percent and have north-to- 

 northeast aspects. The soil is a Typic Cryorthent, with a 

 silt-loam texture. The habitat type is classified as a 

 Tsuga heterophyllaJClintonia uniflora (Cooper and others 

 in press). This study area consists of a mixed stand of 

 western hemlock (Tsuga heterophylla [Raf.] Sarg.), grand 

 fir (Abies grandis [Dougl. ex D. Don] Lindl.), and west- 

 ern white pine. It was clearcut in 1981 and the slash 

 piled in fall of 1982. This is a productive forest site. 

 Annual precipitation at this elevation is 92.3 cm and the 

 mean annual temperature is 5.3 °C (Wellner 1976). 



Study Design 



Two randomized complete block experiments were 

 established on each site. At the low-elevation site, there 

 were four treatments with four replications, and at the 

 high-elevation site there were four treatments with three 

 replications. The high-elevation site was divided into 

 three separate 1-ha areas, each having been clearcut, and 

 having approximately the same slope, aspect, soil, and 

 habitat type. The treatments consisted of: (1) mounded 

 soil beds with competing vegetation not removed, (2) 

 mounded soil beds with competing vegetation removed 

 manually in June and July, (3) a scalped area wherein 

 organic matter and mineral topsoil had been removed, 

 and (4) a conventionally scarified area essentially 

 undisturbed after harvesting (fig. 1). 



The two sites were mechanically prepared in the sum- 

 mer of 1982 by concentrating the forest floor and 

 mineral soil from the top 10 cm of a 1.5-m wide area and 

 forming beds or mounds. Each treatment was approxi- 

 mately 30 m long and, for the mounded treatments, 

 approximately 46 cm high. 



MOUNDED - COMPETITION REMOVED 



MOUNDED - COMPETITION NOT REMOVED 



SCALPED TREATMENT 



MINIMUM SCARIFICATION TREATMENT 



Figure 1.— Layout of treatments 

 wittiin a replication. 



Soil Sampling and Analysis 



Soil samples were taken from each treatment three 

 times during the growing season. Samples were collected 

 from 15 randomly selected sites in each bed, to the seed- 

 hng root zone depth. These samples were categorized by 

 soil type based on their organic/mineral composition. 

 Descriptions of the soil categories used are shown in 



2 



