Field planting was done in mid-April 1969 by experienced planting crews from the Garden 

 Valley Ranger District, Boise National Forest. Planting spades were used. Site preparation 

 and spacing were as described above for direct seeding. 



DATA COLLECTION 



Seedling emergence, survival, and height growth were recorded on each sample scalp and 

 tabulated separately for each plot (treatment) , block (replicate) , and site characteristic 

 (aspect, slope position, slope gradient, slope shape, nature of competing vegetation). 

 Survival during the first year (1969) was assessed at 2- to 3-week intervals from May 1 to 

 September 10. Second-, third-, and sixth-year survival was assessed in September each year. 

 Emergence percentage values were calculated on a per-scalp basis. Survival was based on the 

 total number of scalps with emergent seedlings. The height of the tallest surviving seedling 

 or transplant on each scalp was measured in September each year. 



Probable causes of mortality were assigned for each seedspot or transplant. Criteria 

 used to identify the causes were similar to those of Gashwiler's (1971). 



In the first-year survival assessment, soil samples were collected from six sites distrib- 

 uted throughout the planting area. Samples were taken at depths of 6, 12, and 24 inches 



(15, 30, and 60 cm) on paired scalped and unscalped areas. Percent soil moisture was measured 

 gravimetrically. Maximum soil surface temperatures on each soil sampling site were recorded 



ising thermopapers . 



Weather data were summarized from U.S. Weather Service records at Garden Valley Ranger 

 Station, located 2.5 mi (4 km) from the planting site and at about the same elevation. 



RESULTS AND DISCUSSION 



Emergence 



Emergence of bitterbrush from both the Idaho and Nevada seed sources occurred from the 

 second week of March until mid-April. Wedgeleaf ceanothus emerged from late March until the 

 end of April. Most of the bitterbrush seedlings emerged during the last week of March and 

 the first week of April. Wedgeleaf ceanothus emergence peaked about mid-April. Emergence 

 counts were made May 1 . 



Bitterbrush emergence averaged 99 percent for the Nevada seed source and 97 percent for 

 the Idaho seed source (table 1). Most of the seed spots had clusters of emergent seedlings. 

 There was little site variation in bitterbrush seedling emergence; lower slope sites had 

 slightly lower emergence values. 



Wedgeleaf ceanothus emergence averaged 36 percent, significantly lower (P<0.05) than 

 bitterbrush (table 1). Many seed spots had a single emergent seedling. Emergence was highest 

 (66 percent) on lower slope sites and lowest (13 percent) on upper slope sites. We were 

 unable to identify the reason for the poor emergence of wedgeleaf ceanothus. A 600-seed 

 sample from each seed lot used in the planting was hand sown on a nearby site at the time of 

 the pilot planting. Two-thirds of the seeds were protected by a rodent-proof screen. Sixty 

 percent of wedgeleaf ceanothus produced emergent seedlings in both the protected and unpro- 

 tected plots. This was better than that exhibited by bitterbrush from either seed source 

 (20 to 40 percent emergence) . 



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