SEED PRODUCTION OF WESTERN WHITE PINE. 15 



germination percentage; therefore, the larger the cones the better is the 

 quality of the seed. This is of importance in seed collection. 



10. An idea of the reproductive capacity of a single tree may be 

 gained from the record of the largest yield by an individual white- 

 pine tree, which was 2J ounces, or 6,000 germinable seed. 



11. If from individual trees we turn to stands, we find that normally 

 stocked stands bear from 2\ to 5 pounds of germinable seed per acre, 

 or, assuming an average of 30,000 seed to the pound, from 75,000 to 

 150,000 germinable seed. The apparently small yield of plot No. 3 

 (a little over one-half pound) is explained by the overcrowded condi- 

 tion of the stand. The average of 3 pounds, or 90,000 germinable 

 seed, per acre for a moderately good seed year may therefore be 

 accepted as the average seed crop for the white pine on the Kaniksu 

 and Coeur d'Alene National Forests. Applying this average figure 

 to the different forest types found on the Kaniksu and Coeur d'Alene 

 Forests, and assuming that there are 45,000 acres of white-pine land 

 of which plot No. 1 is representative, 20,000 acres of which plot No. 2 

 is a sample, and 15,000 acres which may be represented by plot No. 3, 

 the total amount of germinable seed produced in 1911 on the Kaniksu 

 Forest would be in the neighborhood of 300,000 pounds. 



This amount is for a moderately good seed year. In exceptionally 

 abundant seed years it would be much larger. These estimates, of 

 course, do not take into consideration any possible destruction of seed 

 by insects or disease, either in the cone or flower. 



12. It is interesting to compare the total yield of germinable seed 

 with the amount of seed actually collected by the Forest Service. In 

 1911 the collection of seed was conducted on an extremely large scale, 

 6,700 pounds being gathered on 20,676 acres. The total amount of 

 clean seed produced during this same year on that area, as ascertained 

 by the study, was 225,368 pounds. The amount collected by the 

 Forest Service constituted, therefore, about 3 per cent of the total 

 amount of seed produced that year. This conveys some idea of the 

 portion of seed which man is able to collect out of the total amount 

 produced by the forest. The remainder is either left on the ground 

 for future natural reproduction or is destroyed by squirrels and other 

 animals. 



WASHINGTON : GOVERNMENT PRINTING OFFICE : 1915 



