220 TWENTY-FIRST REPORT. 



poor growth of the trees on the slopes. It is noteworthy, however, that even 

 the better portions of the area are so poor that the grass cover established 

 between the trees has always been very thin and scant. 



It has long been known that the pines as a class are more frugal than the 

 spruces, i. e., demand less from the soil, in order to make an equal growth. 

 To demonstrate this fact and to secure data for making a definite comparison 

 between pine and spruce on the one hand and different species of pine on the 

 other, three species of pine were planted in the spring of 1915 among the spruce 

 on the spots where the spruce had made the poorest growth. The species 

 planted were Pinus strohus, Pinus sylvestris and Pinus ponderosa. The ages 

 of the stock were as follows : P. strohus, four years ; P. sylvestris, three years ; 

 P. po-ndcrosa, two years. 



The height of all the trees on these plots was measured in March, 1919, 

 after four growing seasons, for the pine and fifteen growing seasons for the 

 spruce. The results of these measurements are shown in the following table : 



— Total Height in Feet — 



Species. Maximum. Minimum. Average. 



Norway Spruce 7.0 0.9 2.88 



White Pine 3.1 0.4 1.3 



Scotch Pine 5.1 2.2 3.8 



Western Yellow Pine 2.0 _ 0.5 1.1 



Since the growth of all of these species is relatively slow during about 

 the first five years after planting, the pines have not yet had a fair chance 

 to show what they can do. At the end of the next five years the differences 

 will undoubtedly be much more striking. But even within the short space 

 of fours years the Scotch pine has been able to make an average total height 

 growth that is one foot greater than that made by the spruce in fifteen years, 

 with a minimum height more than t\\ace that of the spruce. 



If the different species are compared on the basis of the average annual 

 height growth made since the germination of the seed, the.se results are 

 obtained : 



Average Annual Height 

 Species. Growth in Feet. 



Norway Spruce 0.17 



White Pine 0.16 



Western Yellow Pine 0.18 



Scotch Pine 0.54 



During the years to come the average annual growth of all the pines may 

 be expected to increase decidedly while that of the spruce will probably 

 decrease. Just how much the growth of the pines will increase and which one 

 of the pines will be leading at the end, time only will tell. The present figures 

 are merely indicators, but already emphasize the wide difference between the 

 Norway spruce and Scotch pine in adaptability to poor soil conditions. 



The coniferous forests of Europe are composed almost entirely of Scotch 

 pine and Norway spruce, so that a great deal is known as to their rate of 

 growth under European conditions on sites of different qualities. It is inter- 

 esting to compare their figures with the ones given above as a means of eval- 



