GROWTH STUDIES IN FOREST TREES 



2. PINUS STROBUS L. 



H. P. Brown 



Object and scope of the investigation 



(with plates XIII AND XIV AND TWO GRAPHS) 



The present paper is the second of a series presenting the 

 results of studies of growth in forest trees/ The investigations 

 are planned with a twofold purpose, namely to clear up some dis- 

 puted points regarding the formation of annual rings and to out- 

 line the laws of growth in trees. The results of the studies of 

 Pinus Strobus L. are presented in this paper. 



Pinus Strobus L. (white or Weymouth pine) was chosen for the 

 second subject of investigation for several important reasons. 

 First, it is a soft pine and differs from the hard pines, which include 

 Pinus rigida Mill., both in external as well as internal anatomy. 

 Further, it is more rapid in its growth than pitch pine, and inter- 

 esting results were anticipated from a comparative study of the 

 two trees. Finally, white pine is oi recognized commercial impor- 

 tance, and it is hoped that some of the conclusions will prove of 

 interest and value to foresters. 



The specimens in the investigations, aside from the seedlings, 

 were all in the wild state. The investigations were not limited 

 to a few trees or to one locality. Specimens were examined in 

 different woodlots, thereby providing variation in site, soil, and 

 other silvicultural conditions. Seedlings from the nursery beds 

 of the Department of Forestry, N.Y. State College oi Agriculture, 

 Cornell University, small trees from the same, as well as others in 

 the wild state, and older trees which had passed the century mark 

 and presented wide variation in crown development, were all sub- 

 jected to examination. Fully 50 specimens were studied and from 

 them comparative data were secured. It is hoped that the results 

 thus obtained will prove of permanent value in formulating general 



' The first paper appeared in BoT. Gaz. 54:386-403. 1912, and included the inves- 

 tigations upon Pinus rigida MUl. 



197] [Botanical Gazette, vol. 59 



