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15 



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SCARIFIED 

 UNSCARIFIED 



JUNE 1959 



SEPT. 1961 



Figure IS. — Many more seedlings per acre were produced on scarified than on unscarified 



cites following a -very heavy seed crop. 



of 49,720 Douglas-fir seeds per acre fell in the openings. Even with this amount of 

 seed per acre and near-average growing season weather, some areas were below acceptable 

 stocking (40 percent of mil acres stocked) 7> years later. The number of seedlings that 

 germinated was significantly different on scarified and unscarified ground (fig. 15). 

 Germination was poor on unscarified sites, even though large amounts of seed were 

 present; the scarified areas averaged more than 22,000 germinates per acre (fie 16). 

 During the ensuing 3 years, however, mortality reduced the average number of seedlings 

 on scarified sites to about 4,700 per acre in the fall of 1961. 



On scarified ground, the degree o^ stocking after 3 years varied by aspect. The 

 stocking on ridges and on southwest slopes (from S. 45° E. to N. 45° W.) was lower than 

 on northeast slopes (from N. 45° IV. to S. 45° E.) (fig. 17). Mortality reduced the 

 stocking on all three of these sites between June 19S9 and September 1961. On ridges 

 and on southwest slopes, stocking was irregular and unreliable as compared to northeast 

 slopes, where all adequately scarified sites were acceptably stocked (40 percent or" 

 milacres). These data illustrate that f or prompt establishment of ponderosa pine repro- 

 duction there must be site preparation as well as an adequate source of seed. Results 

 also suggest that some method of regeneration other than clearcuttinp may be preferable 

 on sites with southern or western exposure and shallow soils. 



28 



