Periodical Literature 507 



It is of greatest use in situ. It is the office of the timber on the 

 upper slopes to protect the lower in such a way that the latter 

 will yield regularly. If man fails to grasp this important relation 

 and reduces the higher and upper stands in the same manner that 

 he would the lower, he will soon realize that when he comes to cut 

 a second and third time the distance he can go up the slope for 

 timber decreases with each cutting, unless the birch covers up his 

 sins with a cloak of mercy. The office of the upper stands is therefore 

 so to protect the lower that the latter may keep up a constant yield. 



The author then goes into detail inquiry as to what particular 

 function trees in protection forests are called upon to perform and 

 how the three species come up to these requirements. Trees within 

 the protection forest must be able to resist storms. Spruce by its 

 form and lower branching is superior to pine in preventing snow 

 drift, and even in wind firmness spruce is given the preference: 

 root systems of both species in these locations are alike, but pine 

 has its center of gravity above the middle of the bole and is easily 

 thrown, while spruce offers least resistance in the top and break.s 

 only bit by bit. The ability of the spruce to form dense thickets 

 in piu"e stands over extensive areas counts also in its favor. It 

 also by its low crown protects the forest floor better and accumu- 

 lates a copious litter. 



The ameHoration of site at higher elevations by spruce is not 

 unlike that of birch, both of these species rehabilitating through 

 long years the deterioration wrought by centuries of pine stands. 



The many enemies of pine hinder reproduction in a large measure, 

 and this is one of the chief reasons for its yielding and recession 

 on the higher slopes. Furthermore, the seed of pine requires a 

 longer period for ripening — three years high up, and the seed years 

 are infrequent. In addition, it is at best offered a very poor seed 

 bed, so that what faw scattered pine seedlings do occur there can 

 hardly be derived from the trees overhead ; but have come mostly 

 from the trees lower on the slope. In contrast, we know that the 

 seed of spruce germinates in much less time, and where pine seed 

 ripens in three good seasons, that of spruce ripens in one less; if 

 it be unusually warm it may ripen in one season. Aside from re- 

 production from seed upon which the pine depends solely, spruce is 

 able to regenerate by sprouts from buried limbs, and this process 

 is more rapid than generally believed. It is an interesting thing to 



