MAMMOTH CREEK ROAD SITE 



MEAN SURVIVAL 



MAMMOTH CREEK ROAD SITE 



MEAN HEIGHT 



SURVIVAL [») 



TflEE HEIGHT ( CM 



BAREROOT 



IXXX3 



CONTAINER 



1 7771 



■ . " J 



mi 



1985 



CONUINEfl 



YEAH 



1585 



BAREROOT 



[XXX] 



CONTAINER 



17771 



SURVIVAL IX) 



1961 



DAVE'S HOLLOW SITE 



MEAN SURVIVAL 



1982 



1985 



DAVE'S HOLLOW SITE 



MEAN HEIGHT 



TREE HEIGHT [ CM ) 



BAREROOT 



YEAR 



1935 



Figure 4 (Con.) 



The shoot borer decreased the overall mean heights of 

 the trees but did not affect the results because damage 

 was spread evenly between the bareroot and containerized 

 stock. If anything, the insect damage minimized the differ- 

 ence in height growth between sites because the damage 

 was heaviest on the best sites. There is no evidence that 

 shoot borer damage has affected survival. 



Although many of the differences are not statistically 

 significant, the root index in the upper 4 inches of soil 

 followed the fifth year field performance very closely (fig. 

 4 and table 3). This was not the case in the root zones be- 

 tween 4 and 12 inches, however, perhaps because many 

 roots were stripped when they were excavated from the 

 rocky soil, especially at Mammoth Cave. We found few 

 signs of root deformation in either bareroot or container- 

 ized seedlings. 



Other studies comparing bareroot and containerized 

 ponderosa pine were mostly in agreement with our results. 

 On a dry site near Rogue River, OR, bareroot ponderosa 

 pine survived and grew better than containerized seedlings 

 (Helgerson 1985). Both performed very well, however, and 

 the differences were small. In tests on the Lincoln 



National Forest of New Mexico where site and weather 

 conditions are similar to the Dixie, results were mixed 

 (Buchanan 1974). Overall there was no clear winner. Hite 

 (1974) reported superior performance of container-grown 

 seedlings in Rocky Mountain trials. 



CONCLUSIONS 



Container-grown stock has been used operationally and 

 in field tests throughout North America and has per- 

 formed very well within the last few years. In the Dixie 

 National Forest in southern Utah, where soil moisture is 

 low following the planting season, container-grown seed- 

 lings have shown better overall height growth and survival 

 than similar bareroot stock after five growing seasons. 

 Results on five sites vary from little difference in perform- 

 ance on the best sites to significant differences on the 

 harshest sites. As we move from the best to the poorer 

 quality (fig. 4), seedling survival and fifth year mean 

 heights decrease. Also, on the harshest sites the con- 

 tainerized stock performance becomes superior to that of 

 bareroot stock. Nevertheless, even on the best sites in this 



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