For the sake of brevity, these five tests will be outlined briefly and only the 

 specific results indicated. 



Site Preparation, Mulching, and Aspect Tests (Zena Creek) 



Test 1: Pits J Furrows j and Scalps j With and Without 

 Straw Mulch, 1962 



This first experiment at Zena Creek included tests of three site preparation 

 methods. The three methods were: (a) a shallow hand-dug pit (3 by 3 feet with a 

 horizontal bottom surface for planting); (b) a shallow V-trench or furrow made with a 

 rotocat machine (about 4 feet along the contour); and (c) a scalp (3 by 3 feet). The 

 sites were prepared in the fall of 1961. The 2-0 ponderosa pine seedlings were planted 

 in May 1962. A straw mulch (3 by 3 feet) was placed around half of these seedlings to 

 stabilize soil and conserve moisture; the remaining seedlings were left as planted. 



The two test areas were selected to provide a range in soil depths. Both areas 

 were at about a 5,000-foot elevation, on southwest aspects, with slopes averaging 

 70 percent. 



Soil depths were quite variable in each area. Thirty-three soil pits (table 2 

 and Appendix 1) showed a range in depths to bedrock of 7 to 24 inches for Area 1 and 

 14 to 38 inches for Area 2. Three blocks were established in each area to reduce the 

 influence of this variability on the statistical analysis of survival- 



Seedling survival counts on the two test areas were made each fall from 1962 to 

 1966 (Appendix II). In the analysis of variance of seedling survival, after the 1962 

 growing season, 48.5 percent of the total variation was due to block differences in 

 areas . 



Table 2 . --Average soil depths (inches) to bedrock. Test 1 



(Zena Creek) 



Test 

 area 1 



Test 

 area 2 



Combined 



Site preparation 



areas 



STRAW MULCH 



Inches 



Scalps 



Pits 



Furrows 



13.7 

 11.0 

 16.0 



25.3 

 22.3 

 25.7 



19.5 

 16.7 

 21.8 



NO MULCH 



Inches 



Scalps 



Pits 



Furrows 



19.3 

 18.8 

 20.0 



29.3 

 25.2 

 19.7 



24.3 

 22.0 

 19.9 



