24 BULLETIN 327, U. S. DEPABTMENT OP AGEICULTUEE. 



even-aged stands when the latter are more or less suppressed. Domi- 

 nant trees 6 inches in diameter in an open stand are about 30 years 

 old, while dominant trees of this size grown in a dense stand are from 

 about 40 to 120 years old. Trees 16 inches in diameter that have 

 grown in an open forest are about 130 years old, while dominant 

 trees 12 inches in diameter grown in a close stand are about 156 years 

 old. Suppressed trees 6 inches in diameter may be from about 50 to 75 

 years old, according to the density of overhead shade. In excep- 

 tional cases wholly suppressed trees 2 to 3 inches in diameter may 

 be from 75 to 100 years. 



ALPINE FIR. 



Abies lasiocarpa (Hook.) Nuttall. 



COMMON NAME AND EARLY HISTORY. 



Alpine fir is one of the smallest of the western firs and perhaps 

 also one of the least known there, owing to the fact that it grows 

 chiefly at high altitudes. The common name, " alpine fir," adopted 

 here, would seem to be the most appropriate one for this species, 

 because it refers to the tree's high mountain habitat. 1 Woodsmen 

 and settlers usually call it " balsam " or " mountain balsam." 



It is probable that alpine fir was first discovered in September, 

 1805, by Lewis and Clark, while crossing the Bitter Eoot Moun- 

 tains (whether on the Montana or Idaho side is unknown), for 

 the narrative 2 of their exploration of our Northwest mentions " a 

 growth of eight different species of pine," which by exclusion must 

 have included this fir. 3 To David Douglas belongs the credit of 

 having first collected a specimen of this fir in 1832 in the " interior 

 of N. W. America." On this specimen is based the first published 

 technical description and name of the tree, " Pinus (Abies) lasio- 

 carpa Hooker," published in 1839, and on which the present name, 

 Abies lasiocarpa (Hooker) Nuttall, is founded. Dr. C. C. Parry 4 

 seems to have been the first to find alpine fir in our central Rockies 

 (Colorado), where he observed it in 1862, and from which in 1863 

 he distributed seed. 5 It was not known, however, until 1876 that the 



1 Abies lasiocarpa is frequently called " balsam fir," probably because of its general 

 resemblance to the true balsam fir (AMes balsamea), to which, however, this name prop- 

 erly belongs, having been applied to it long before the alpine fir was known to botanists. 



2 History of the Expedition under Command of Lewis and Clark, 1S04-1S06 (ed. Dr. 

 Elliott Coues), II, 598. 



3 It was common in the early days, even for botanists, to designate as " pine " the trees 

 we now know as firs. 



. 4 Engelmann in Am. Nat., 555, 1876. 

 6 There appears to be no record of plants raised from this seed. Probably the first 

 trees known in cultivation were grown from seed planted in 1873 in the Arnold Arbore- 

 tum, Massachusetts. Their growth in height for the last 40 years has, however, been 

 excedingly slow, amounting to only about 3 or 4» inches per year. Alpine fir seems to 

 have been introduced into England in about 1890, but according to Elwes and Henry 

 (Trees of Great Britain and Ireland, IV, 803, 1909) its growth there has been practically 

 a. failure. The German Government imported seed of this fir for forest experiments in 

 the early nineties, and these trials show the tree to be better adapted to the climate of 

 Germany than to that of England. 



