Other small mammals and birds also destroy ponderosa pine seed before it is 

 disseminated (Curtis 1948). In addition, many insects such as pine seed moths 

 [Laspeyvesia spp.) or the ponderosa pine cone beetle (Conophthorus ponderosae Hopk.) 

 infest the cones and seeds of this species (Keen 1958) . During years of low production 

 insects may nearly destroy the entire crop of seeds. 



Because good cone crops are infrequent, it may be desirable under some circum- 

 stances to stimulate cone production. The inherent genetic differences governing 

 cone production presently preclude accurate predictions of which individual trees will 

 respond to cone stimulation treatments. However, these studies indicate that girdling 

 can stimulate production of ovulate buds for one season in about 80 percent of the 

 50-year-old pine trees. Older trees may respond to girdling also but stimulation will 

 likely occur in only about one-half of the trees and the effect may be delayed a year 

 longer than in the younger trees. These differences between young and old trees are 

 probably due to the decreasing physiological activity associated with older age. 

 Girdled trees recover rapidly from these wounds; stimulating effects are of short 

 duration. Release did not increase cone production of the selected trees during the 

 first two or three years; however, these trees may require several years to adjust to 

 their new growing space before cone production is influenced. 



Only the abundant seed years produce enough seed for germination and a level of 

 survival that will assure adequate natural regeneration. Mice and chipmunks as well as 

 other ground-dwelling mammals rely upon dispersed ponderosa pine seed for a significant 

 part of their fall and winter diet. Attempts at control with one application of poison 

 bait were unsuccessful here as well as in many other areas (Foiles and Curtis 1965b) . 

 Successful rodent eradication in Oregon required three applications of poisoned bait 

 (Stein 1964) . 



Seeds that have survived the series of depredations up to the time of germination 

 are potential seedlings, but as seedlings they will still face formidable survival 

 barriers. In most years, competing vegetation reduces soil moisture to a level which 

 is inadequate for survival of young seedlings. 



Treatments that reduce competing vegetation and conserve soil moisture will pro- 

 mote seedling establishment in most years. Prescribed burning when fuels are dry, or 

 heavy scarification in well distributed spots throughout a cutover area, offer two 

 good choices for seedbed preparation. However, when an occasional heavy seed crop is 

 followed by above average rainfall during the next growing season, as happened in 1949, 

 some pine seedlings survive and restock many areas even though mineral soil may not be 

 exposed (Pearson 1950, Foiles and Curtis 1965a). 



Many old-growth ponderosa pine stands in western Montana grow on sites that are 

 climax for Douglas-fir. As a result, most sites are usually well stocked with advance 

 Douglas-fir seedlings. If the forest manager desires this regeneration, nothing more 

 than some thinning and weeding is necessary to maintain these areas in a well-stocked 

 condition. However, if he wants to establish ponderosa pine, the fir competition 

 must be removed or drastically reduced. 



In addition to the usual physical and biological factors limiting seedling estab- 

 lishment in western Montana, high deer populations in some localities frequently kill 

 or severely browse the trees. Such browsing may occur until the trees are tall enough 

 so the foliage is out of reach of these animals (Adams 1949, 1951a, 1951b). 



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