SEEDING HABITS OF SPRUCE AS A FACTOR IN THE 



COMPETITION OF SPRUCE WITH 



ITS ASSOCIATES 



LOUIS S. MURPHY 



U. S. Forest Service, Washington, D. C. 



I wish to make it entirely clear at the outset that my contri- 

 bution to this discussion is chiefly by way of suggestion, and 

 that the observations on which my paper is based were hardly 

 sufficient to justify too positive a conclusion. Yet, I take it 

 that you are not averse to having brought to your attention pre- 

 liminary findings which point the way to promising new fields 

 of research. 



Doubtless many, if not all, of you are familiar with the fact 

 that red spruce (Picea ruhens) bears a full crop of seed only at 

 infrequent intervals, which vary from four to seven years. This 

 in itself is a considerable handicap, and is indeed generally so ac- 

 cepted in accounting for the paucity of spruce reproduction as 

 compared with that of balsam fir and the hardwoods with which 

 it is associated, most of which are annual seeders. Other causes 

 commonly assigned to this failure of spruce to maintain itself 

 in the young growth with species with which it is able to compete 

 so successfully in later life are its exacting demands on seed bed 

 as to moisture, texture, and acidity of the soil, and its extremely 

 slow growth in early life even under most favorable circum- 

 stances. 



Still another factor, however, the early dispersal and germina- 

 tion of spruce seed, may also be concerned. It is this factor 

 hitherto apparently unnoticed which I wish to present for your 

 consideration. My observations on this point were made in the 

 fall of 1910 and the spring of 1911 when I was engaged in a study 

 of the growth and development of spruce stands, particularly 

 "second growth," or "old pasture," stands. It so happened 



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