REFORESTATION IN MASSACHUSETTS. 29 



species; but good, straight timber is produced, which finds a 

 ready market. The limbs do not drop off readily, however, and 

 clear timber can therefore be grown only in dense stands. 



The tree reproduces itself well when the leaf litter on the 

 ground is not too thick, and the seedlings therefore start readily 

 under the mature trees of the same species, forming a stand 

 containing trees of all ages. 



The principal enemy is the spruce bark beetle (Dendroctonus 

 piceaperda). 



The uses of the wood are well known ; building timber, piano 

 sounding boards, inside finish, clapboards, and in Maine pulp- 

 wood, are among them. 



Norway Spruce (Picea excelsa). 



This is one of the principal timber trees of Europe, and is 

 strongly recommended for planting in this country, possessing, 

 as it does, all the advantages of the red with the added one of 

 being a much more rapid grower. 



2. NORTHERN HARDWOODS. 

 Rock Maple (Acer saccJiarum) . 



This tree, known also as the sugar maple, is one of the most 

 important of our northern hardwoods, both for sugar and tim- 

 ber. It grows usually in mixture with beech, oaks, ashes, etc., 

 as well as conifers, but may grow in pure stands. 



Its chief sylvicultural feature is its extreme tolerance, mak- 

 ing it the most shade-bearing of all American hardwoods, with 

 the possible exception of beech. A deep, moist soil is neces- 

 sary for good growth. 



Seed is produced almost every year, but full seed years 

 occur only at intervals of from three to five years. The per- 

 centage of germination is rather low, but this is offset by the 

 ability of the young trees to stand dense shade. 



Growth is slow, but persists for a long time, the tree reach- 

 ing a height of 70 or 80 feet and a diameter of 2 or 3 feet. 

 The tree is not very wind-firm. 



Rock maple is not very susceptible to injury by fire or fungi, 

 though a good deal of damage is sometimes done by the forest 



