35 40 



Figuve 3. — Map showing the 18 mountain ranges sampled at "detailed" level and isolines 

 of the average total vegetal cover (percent) on these ranges. Average total vegetal 

 cover for each mountain range is given in table 4. 



The total vegetal cover per plot increased steadily as elevation rose from 1,800 

 to 2,200 m (fig. 4). The change in vegetal cover was insignificant between 2,200 and 

 2,600 m. All of the 1,600 m plots (2) were located at Black Pine Peak, Idaho, near the 

 northernmost limits of the study area. Thus these plots involve cooler temperatures 

 and more mesic sites. The only 2,800 m plot was located on the White Mountains on a 

 site with rocky, shallow soil that could not support much vegetation. 



15 



