Table S . --Percentage of 3-year seedling and transplant mortality attributable to specific causes^ 



Cause 



5itterbrush , 

 Idaho 

 N=159 



Seedling 



?itterbrush, 

 Nevada 

 N=307 



Wedgeleaf 

 ceanothus , 

 Cal ifornia 

 N=140 



Aver- 

 age 

 N=606 



Jitterbrush , 

 Idaho 

 N=90 



Transplant 



Jitterbrush, 

 Nevada 

 N=284 



Wedgeleaf 

 ceanothus , 

 California 

 N=151 



Aver- 

 age 

 N=525 



Weather 



Drought 

 Heat 



Frost heave 



Animal 



Small mammal 

 Insect 

 Trampl ing 

 Browsing 



Disease 



(damping-of f ) 



Soil movement 



Planting technique 



Unidentified 



42 

 1 

 



7 

 4 

 14 

 2 



3 

 1 

 



26 



35 

 

 



7 

 2 



10 



7 



2 

 1 



1 



34 



32 

 

 





 

 

 46 



36 

 1 







7 

 3 

 11 

 4 



2 

 1 

 1 



35 



38 

 

 1 





 

 9 



39 



29 

 

 1 



58 



25 

 

 2 



18 

 

 3 





 

 2 

 43 



29 

 

 1 





 

 4 



51 



^Seedling N is the number of seed spots to which a cause of mortality was assigned; transplant N is the number of 

 transplants to which a cause of mortality was assigned. 



About 25 percent of seedling losses and 15 percent of transplant losses were caused by 

 animal activity. Trampling by deer and clipping, root cutting, and mound building by pocket 

 gophers {Thomomys talpoides Merriam) were mainly responsible. Wedgeleaf ceanothus transplants 

 were particularly susceptible to root cutting by pocket gophers. Trampling killed 11 percent 

 of the seedlings and 2 percent of the transplants. This difference was the largest of any 

 single cause of mortality between seedlings and transplants. Insects (mostly grasshoppers, 

 webworms , and cutworms) also killed more seedlings than transplants. The planting was aerially 

 sprayed (Malathion) in mid-July of the first growing season as part of an area-wide grasshopper 

 control program. 



Browsing by deer killed 4 percent of the seedlings and 3 percent of the transplants. Most 

 of the browsing mortality occurred between the second and third growing seasons, a period 

 separated by a severe winter. A decrease in average shrub height for some treatments the 

 following year (year 3 in table 1) probably reflected the heavy browsing of that winter. 



Damping-off fungi and soil movement accounted for 3 percent of seedling mortality. Four 

 percent of transplant mortality was attributed to poor planting technique; most of this was 

 from doubled-up root systems. 



Although not reflected in table 5, we later observed winter injury and winter kill of 

 wedgeleaf ceanothus. 



11 



