& 



Figure 1 — Location of study sites for version 2 of the Regeneration Establishment 

 Model. Triangles are stands sampled by Carlson in 1979-82. Squares are stands 

 sampled by Ferguson and others (1986) in 1975-76. Circles are stands sampled 

 by Ferguson in 1979-82. 



STUDY DESIGN 



Data for version 2 of the regeneration model were collected during three 

 studies. The grand fir-cedar-hemlock ecosystem of northern Idaho, sampled 

 in 1975-76, was used to develop version 1 of the regeneration model (Ferguson 

 and others 1986). Data from western Montana were collected by Carlson from 

 1979-82. Data in central Idaho and the Pseudotsuga menziesii and Abies 

 lasiocarpa series in northern Idaho were collected by Ferguson from 1979-82. 

 Data collection was similar among the three studies. These data were com- 

 bined to develop version 2 of the regeneration model. 



A stratified random design was used to select stands that were harvested 

 2 to 20 years prior to sampling. Stratification variables were habitat type 

 series, site preparation, regeneration method, and history of budworm defolia- 

 tion. Four to five stands within each stratification category were randomly 

 chosen for sampling. 



3 



