WESTEKIf YELLOW PINE IN OEEGON, * 11 



ing it off at the base with a smoldering flame. An examination of a 

 great many bm^ns in eastern Oregon shows that an average surface 

 fire, on land which has been periodically burned over before, kills in 

 this way one merchantable tree on from 1 to 4 acres. The aver- 

 age number on 130 sample acres examined in detail was one tree 

 to every 1.12 acres. Tliis is not a large number of trees, and they- are 

 so scattered about in a burn as not to be conspicuous; but in the 

 aggregate it is an enormous loss, especially as each of the repeated 

 fires may kill the same number, and the trees felled by these surface 

 fires are usually the larger ones. 



(3) The "pitching" of the butts of commercial trees. 



Trees that are fire-scarred or which have been excessively heated 

 about their bases are very apt to become " pitch-butted; " i. e., a great 

 deal of ''fat" pitch is deposited in the wood in the lower part of the 

 stem. This pitch greatly lessens the value of the log for lumber 

 because excessive pitch is a defect which bars lumber from the best 

 grades on the market. A tally of 1,184 butt logs in the Blue Moun- 

 tains shows that 25 per cent of them are ''pitched" and that the aver- 

 age diameter of the pitchy area on the basal cross section of the log 

 is 14.7 inches. This indirect result of surface fires is not conspicuous, 

 but is a very real source of loss. 



(4) The impoverishment of the soil by repeated burnings. 

 Frequent fires consume the vegetable matter, which should be 



allowed to accumulate and decay and thereby better the physical 

 condition and add to the fertihty of the soil. 



(5) Destruction of the reproduction which should form the basis 

 for the next crop. 



Each fire kills the seedlings and some of the saplings, so that, if 

 the fires are of frequent occurrence, no young growth has a chance to 

 replace the mature trees that die from natural causes. Yellow pine 

 normally occurs in Oregon in uneven-aged stands in which trees of 

 all ages are in intimate mixture ; frequent fires prevent the stand from 

 having the proper number of young trees. If this process is con- 

 tinued long enough, it will annihilate the yellow pine by gradually 

 killing off the old trees and at the same time preventing the survival 

 and maturity of any young ones. This very thing has happened in 

 places in the Siskiyou Mountains and southern Cascades. Here 

 areas once covered by fine stands of yeUow-pine timber are now tree- 

 less wastes, covered only by brush or mock chaparral. 



(6) Degeneration in the forest type. 



In certain parts of the State repeated surface fires have the effect 

 of transforming the forest type from a stand consisting largely of 

 yell(nv pine to one consisting of lodgepole pine, whose reproduction is 

 extremely abundant and vigorous after fire. 



