* 



INTRODUCTION 



Following harvest cutting, natural regeneration of ponderosa pine (Pinus 

 ponderosa Laws.) in western Montana usually is uncertain. Therefore, forest managers 

 frequently rely on planting to promptly regenerate ponderosa pine and prevent future 

 gaps in volume production. When the forester decides to restock an area by natural 

 regeneration, he must effectively manipulate the factors under his control that 

 influence seedling establishment. 



Good ponderosa pine seed crops occur at irregular intervals (USDA Forest Service 

 1965); thus, timing of site preparation to coincide with seed production is a critical 

 requirement for successful natural regeneration. Once cones are initiated, it is 

 important to understand the factors influencing their survival. In addition, stimula- 

 tion of cone production by girdling or release of seed trees would be a useful tool if 

 ponderosa pine responds to either of these treatments. 



Even when a sufficient seed crop is produced, the success of natural regeneration 

 is further influenced by: (1) dissemination to a favorable seedbed; (2) seed loss to 

 biotic agents; (3) germination of the remaining seed; and (4) survival of germinated 

 seedlings . 



All of these facets of natural regeneration were studied in western Montana from 

 1948 to 1962. Five studies were conducted at eight locations (fig. 1). The factors 

 kstudied on each area are shown in table 1. 



Table I. --Factors studied that influence natural regeneration of 

 ponderosa pine in western Montana by study area 







Factors studied 



Study area 



Cooperators 



Cone : 



Cone : Seed : 



Seed 



: Seedling 







pro- : 



stimu- : disper- : 



sur- 



: estab- 







duction : 



1 at ion : sal : 



vival 



: lishment 



Northwestern Montana 

 Bluesky Creek 

 Butler Creek 

 Dunn Creek 

 Jackson Creek 

 Karland Creek 



Kootenai N.F. 

 St. Regis Paper Co. 

 St. Regis Paper Co. 

 Kootenai N.F. 

 Kootenai N.F. 



3y x 



Southwestern Montana 

 Buck Creek 

 Lick Creek 

 Marshall Creek 



Bitterroot N.F. 

 Bitterroot N.F. 

 Anaconda Forest 



Products and 



Lolo N.F. 



Complete evaluation of cone development and loss, 

 2 Squirrel cutting. 



