882 JOURNAL OF FORESTRY 



Seed I'roductioit from Individual Trees 



Studies on the Coeur d'Alene indicate that trees begin to produce seed when 

 about 8 inches d. b. h., and that the maximum seed production occurs in trees 

 from 15 to 25 inches d. b. h., of from 5,000 to 11,000 seeds per individual tree. 



Tlicre seems to be no definite relation between size of tree and germination 

 per cent of seed produced. The curve rises rapidly to trees of 8 inches d. b. h., 

 and then gradually falls off in trees from 8 inches to 25 inches d. b. h. 



Cone production begins on trees of 8 inches d. b. h., and all the trees from 20 

 inches to 30 inches d. b. h. bore cones. 



The numl)cr of seed produced per tree, averaged by d. b. h. classes, increases 

 from a few hundred at 8 inches d. b. h. to a maximum of 7,500 at 25 inches to 

 27 inches, after which it begins to decrease again. 



On the basis of the above data, it is estimated that the number of good white- 

 pine seed per acre to be expected is 2,875 oi old seed stored in surface duff, plus 

 5.000 additional seeds from each seed tree 16 inches to 18 inches d. b. h. left 

 after cutting. Owing to failure of the seed to develop from various causes, 

 5 per cent of these figures should be a conservative estimate of the number of 

 healthy plants per acre to be expected from this seed at the end of the second 

 year. 



Combining these figures for one to six seed trees per acre of this size re- 

 served, the following results in number of healthy white-pine seedings per acre 

 are indicated : 



Number of seed trees 16 Number of white-pine seed- 



inches to 18 inches d. b. h. lings per acre to be ex- 



per acre reserved. pected after two years. 



1 420 



2 700 



3 980 



4 1,260 



5 1,540 



6 1,820 



Seed Distribution 



Seed will be distributed, in a sufficient amount for satisfactory reproduction, 

 to a distance of from two to five chains from the parent tree, depending primarily 

 upon the size of the crown and the tree's strategic location. 



Competitive Strength 



If given an equal start with other species, white pine will unquestionably form 

 a considerable part of the dominant stand. Even a relatively small number of 

 white-pine seedlings per acre, other conditions being equal, will outstrip other 

 species and form the dominant stand. 



Recovery After Thinning 



White-pine trees, after being badly crowded in dense stands, will increase in 

 growth when the stand is thinned. 



Fire Resistance 



White-pine trees of any size are easily killed by fire, even by light ground 

 fires. 



