Figure 1 — Actual levels of infection (percentage) by Lopho- 

 dermium baculiferum for populations of ponderosa pine. 



= no needle tissue infected 



1 = less than 5 percent of needle tissue infected 



2 = from 6 to 36 percent of needle tissue infected 



3 = from 37 to 69 percent of needle tissue infected 



4 = more than 70 percent of needle tissue infected. 



Before analysis, the five categories were changed to the 

 mean proportion of each class, that is: 1 = 0.025; 2 = 

 0.21; 3 = 0.53; and 4 = 0.85. For computing purposes, 

 = 0.0004. 



An analysis of variance was used to determine 

 significant differences among stands. Multiple regression 

 analyses were used to relate the degree of infection to 

 elevation and geographic location of the seed source. 

 Independent variables included elevation, latitude, 

 longitude, northwest-southeast coordinates, southwest- 

 northeast coordinates, and their squares. The northwest- 

 southeast coordinates equaled latitude x longitude and the 

 southwest-northeast coordinates equaled (1/latitude) x 

 longitude. The geographic variables were nested within 

 two geographic regions: Idaho north of the Salmon River 

 and Montana west of the Continental Divide (Rehfeldt 

 1980; Rehfeldt and Wykoff 1981). A stepwise multiple 



regression procedure for maximizing R 2 (SAS 1982) was 

 completed. 



Predicted infection values for geographic areas were 

 produced using the best fit multiple regression equation 

 for a constant elevation. Contour lines (isopleths) sepa- 

 rating statistically equal levels of infection were deter- 

 mined by using the least significant difference formula 

 (Steel and Torrie 1960) at a i-value of 0.2. The effect of 

 elevation was determined by using the regression coeffi- 

 cients for the elevation factors of the multiple regression 

 equation to predict infection values for a geographic 

 intercept. 



Progeny Test 



Open-pollinated seed from 234 families was collected 

 from 48 stands in northeastern Washington and Idaho 

 north of the Salmon River. (Seed from these 48 stands 

 was also included in the provenance test described above.) 



The seedlings were grown as described for the pro- 

 venance test. The experimental design was a randomized 

 complete block design but with five replications (blocks). 

 Four progeny from each family were planted as a four- 

 tree row plot. 



2 



