Because chipmunks cache some ponderosa pine seeds they never recover, the amount 

 consumed might be slightly less and the amount available for germination might be some- 

 what greater than indicated. West (1968) found that up to 15 percent of the ponderosa 

 pine seedlings in central Oregon resulted from seed caches not consumed by the animals. 



Although animals play the most obvious dramatic role in seed production, they act 

 only during the last 9 or 10 months of a 33-month cycle that terminates at the beginning 

 of seed germination. During the 2 years prior to germination, the seed users are far 

 overshadowed in importance by more subtle factors. Large potential cone crops are 

 drastically reduced by abortions; thus a population explosion of trees is prevented long 

 before animals begin harvesting the seeds. However, after the seeds mature, animals 

 become very important and efficiently utilize this available food, as shown in the 

 following tabulation: 



Description 



Percent 



Number 



Seeds reaching maturity 



Seeds used by animals before dispersal 



Seeds dispersed 



Seeds used by animals after dispersal 

 Seeds available for germination 



88 



66 



100 

 66 

 34 

 30 

 4 



12 



