IMPORTANT FOREST SPECIES 397 



divided into 5 parts. This being done, one-third of the oak of the first compartment is 

 barked the first year, choosing the trees here and there over the whole extent of the 

 compartment. The second and third years the work is continued similarly in Compart- 

 ments Nos. 2 and 3. The sixteenth and seventeenth to the thirtieth years the second 

 third of the trees is barked in Compartments Nos. 1 to 15. The thirty-first and thirty- 

 second to the forty-fifth years the third third is barked in each compartment. In the 

 forty-sixth year the bark has reached the proper thickness on the trees in Compartment 

 No. 1 which was peeled the first time. . . . This method appears to be more con- 

 servative than peeling the trees in the entire compartment at one time. It is nearly the 

 same idea that is expressed in the treatment of the Corsican pine when the selection 

 system was adopted because of the fire danger in yoxmg even-aged stands which foUow 

 the use of the shelterwood compartment method of regeneration. 



SILVER FIR 



(Abies pedinata) 



Size. — Silver fir is a tree of first-class size; it may, when from 180 to 200 years of 

 age, reach 131 feet in height and 6.5 feet in diameter breast-high. Its longevity is 

 very great, and some trees 800 years old have been observed in the Pyrenees. . . . 

 A silver fir 207 feet high and 10 feet in diameter has been discovered in a Bohemian 

 virgin forest (Hochstetter). In France itself ... on the best soils, 131 feet in 

 height is often exceeded. A silver fir in the G^rardmer State Forest is 164 feet high. 



Habit. — The straight, slender bole branches regularly. . . . At an advanced 

 age . . . the crown becomes more and more flattened; this is the period when 

 full seed crops are produced. . . . The loss of the leader or main shoot is more 

 serious with fir than with any other species. Often this leader cannot grow out again, 

 particularly if the tree is a veteran. . . . 



Root System. — The tree is well rooted. There is a tap root, 3 or more feet deep, 

 which divides into long, stout laterals. When cut flush with the ground the stump 

 and root wood is about 16 per cent of the total volume. 



Crown. — The foliage of fir is abundant and leaves may be persistent for 8 to 10 

 years. . . . These leaves and young shoots are readily browsed by cattle and 

 game. 



Bark. — Silver fir bark . . . is in most cases a characteristic silvery gray color 

 . . . the thickness increases with age but rarely exceeds 1.18 to 1.57 inches. . . . 



Natural Grafting. — Silver fir has a growing bark up to an advanced age. This allows 

 the bole, branch, or roots to easily grow together when the parts happen to remain in 

 contact for some time. From this numerous vegetative phenomena arise. One of the 

 most frequent and interesting phases is when the stump (after the tree has been felled) 

 . . . continues to increase in diameter, and produces an excrescence which gradually 

 covers the surface. . . . This growth ... is due to the extensive adhesion 

 of one or more roots of the tree that has been cut down with those of a neighboring 

 unfelled fir. The latter . . . acts as a wet nurse for the stump and causes a 

 continuation of growth. 



Seeding. — Seeding is fairly regular and constant, having none of the irregularities 

 that are so common with certain other species, such as pine, oak, and beech. 



The seed is easily distinguished by its irregular, truncated shape, its shiny brownish- 

 yellow color, and its size which is larger than most other firs. It contains a great deal 

 of turpentine which gives it a pungent, hot taste; it is covered by a brownish opaque 

 husk, some remnants of which always remain, even when cleaned. There are 10,450 



