INTRODUCTION 



'■■s. 



Spring has been the preferred season for planting coniferous forest trees in the 

 northern Rocky Mountain area for many years. Prior to 1940, no distinct preference for 

 any particular season was apparent. Following publication by the USDA Forest Service 

 of survival comparisons between plantations established in the fall and the spring over 

 a 27-year period, preference shifted sharply to spring planting (Schopmeyer 1940).^ 

 This summary showed a long-term advantage of spring planting that averaged 7 percentage 

 points for western white pine {Pinus montiaola Dougl.) and 10 for ponderosa pine {Pinus 

 poyiderosa Laws.). Although not as well represented in the compilations as western white 

 and ponderosa pine, similar results were observed for western larch {Larix oaoidentalis 

 Nutt.), F,ngelmann spruce {Picea engelmannii Parry), and interior Douglas-fir {Pseudotsuga 

 menziesii var. glauca (Beissn.) Franco). 



Fall planting again became a substantial part of the reforestation effort in the 

 late 1950 's and early 1960 's. An expanding planting program made it desirable to spread 

 nursery and planting efforts over more time. An even more important consideration 

 is the late spring accessibility of many remote and high elevation planting sites. 

 Where access is blocked by snow, spring planting is either delayed until long after the 

 planting area itself is free of snow or extra expenses must be incurred to get to the 

 site in early spring. 



^Schopmeyer ' s results were based on the gross performance of many operational 

 plantings throughout the northern region--not on designed test comparisons. 



