﻿16 BULLETIN 13, U. S. DEPARTMENT OF AGEICULTURE. 



Germination of Seed and Growth of Seedlings. 



When fresh, from 70 to 90 per cent of white-pine seeds are fertile, 

 and under favorable conditions will germinate. With unfavorable 

 Conditions, however, the mortality is very great. Much of the seed, 

 either while in the cone or after it falls to the ground, is consumed by 

 birds and rodents. Of the seeds which escape destruction by ani- 

 mals, many die through falling on unfavorable sites. After germi- 

 nation seeds need, for example, a certain amount of moisture, though 

 too much will cause them to decay. Seeds which fall during dry 

 seasons may he dormant until the next year, provided they are not 

 destroyed in the meantime. When properly stored, white-pine seeds 

 tan be kept for five years or more without great loss, but under natural 

 conditions it is probable that only a very small proportion ever germi- 

 nate after the second spring following their ripening. Quantities of 

 pine seed are destroyed by forest fires, which may burn the cones on 

 the trees or destroy the seed after it has fallen. When drought and 

 forest fires follow the falling of seed during an off year, nearly the 

 whole of the crop may be lost. 



Germination takes place, as a rule, in the spring, and in practically 

 every kind of soil with sufficient heat and moisture. If the young 

 seedling is to live, its roots must soon find the mineral soil. Young 

 plants which spring up on insufficiently decomposed leaf litter are 

 almost sure to die. 



Seedlings thrive in soil which is at once moist, porous, and well 

 drained. Sandy or loamy soils, well mixed with decayed organic 

 matter, and protected by vegetation or leaf litter, meet these require- 

 ments. Should the soil dry out even to the slight depth to which 

 the roots of the seedlings have penetrated, a great many of the young 

 trees will die. 



To determine the effect of moisture conditions upon the death rate of 

 seedlings during the first two years of lif e, nine sample plots were marked 

 out in 1909 near Petersham, Mass., in dry, fresh to moist, and wet 

 situations. The dry situations were either entirely unshaded or only 

 partially shaded by underbrush, and had from 2 to 3 inches of pine or 

 else from 4 to 5 inches of broadleaf fitter. The fresh to moist situations 

 were well drained, lightly shaded, some bare of pine litter, and others 

 with a cover up to 3 inches in depth. The wet situations were low, 

 poorly drained bottom lands on which water stood during a part of 

 the spring. The average number of seedlings on the plots in 1909 

 was : In the dry situations 29, in the fresh to moist 60, and in the wet 

 14. When counted in 1910 the proportion still alive in the dry situ- 

 ations was 53 per cent, and in the fresh to moist 86 per cent, while in 

 the wet none had survived. 



As long as the young roots extend but a few inches into the ground 

 the character of the subsoil makes little difference; but as the roots 



