MANAGEMENT PLANS THE NATIONAL FORESTS 



57 



(D) PROTECTION 



The fire hazard is iiot great. The total acreage burned over during the last 

 five years is almost negligible, being approximately 45 acres, or about 9 acres 

 per year. This five-year period includes 1924, one of the worst fire seasons on 

 record. 



Mistletoe is present in western yellow pine throughout the circle. It is not 

 serious, however. Provision for doing what is possible to control this disease 

 is included in the marking-policy statement. 



There has been no serious outbreak of insects. A few scattered trees infested 

 with beetles (Dendroctonus) are to be found. Provision for control is likewise 

 made in the marking-policy statement. 



(E) GROWTH AND YIELD 



Detailed data on growth and yield are very incomplete. The figures used 

 herein were derived from an analysis of timber estimates and are believed 

 to be conservative? 



Slowness and lack of uniformity are the outstanding features of growth in 

 this region. Excluding stagnant stands, the average d. b. h. at 80 years is 

 S inches and at 160 years 18 inches. This is generally true for all species 

 except lodgepole pine, which rarely attains 18 inches d. b. h. It is believed 

 that western yellow pine and Douglas fir make more rapid growth as indi- 

 vidual trees here than does any other species. This is to be expected on this 

 circle, which is better suited for pine and fir than for other species. 



The possible average annual increment is estimated at about 87 board feet 

 per acre. However, much of this is now offset by overmaturity, windfall, and 

 disease. The net usable annual increment of merchantable material is esti- 

 mated to be 45 board feet per acre. In time, as utilization becomes more 

 intensive, the net increment will approach more nearly the 87 board feet, 

 (Basis for these figures will be found on p. 63.) 



Any growth on the 34,190 acres of mature stands is balanced by decay and 

 -death. Of the remaining national forest area, 10,610 acres can become produc- 

 tive only by being planted. This leaves 48,720 acres of actual growing stands, 

 which are estimated to have an annual increment of at least 45 board feet 

 per acre, or a total annual increment of 2,192,400 board feet. If the open 

 acreage is planted during the first cutting cycle and the areas of mature and 

 overmature timber are cut over, the average net annual increment at the end 

 of the first cutting cycle might be figured on this basis at 3,439,125 board feet ; 

 for it is logical to assume that growth on the 34,190 acres containing mature 

 and overmature timber will amount to 45 feet per acre as soon as cutting takes 

 place. 



Summary of volume and acreage hy age classes 



Age class 



National- 

 forest 

 acreage 



Volume 



Avail- 

 able 

 to 

 cut 

 now 



Volume available to cut 

 now 



Total 

 reduced 



Saw rp. „ 



timber ^^^^ 



1 



Props 



Saw 

 timber 



Ties 



Props 



to board 

 measure 



Mature and over- 

 mature 



Intermediate; ma- 

 ture in 40 to 80 

 years 



34, 190 



22, 860 

 16, 020 



9,840 

 10, 610 



Board 



feet 



27, 016, 000 



17, 200, 000 

 14, 065, 000 



5, 270, 000 



Num- 

 ber 

 256, 000 



223,000 



184,000 



136,000 



Linear 



feet 



11, 512, 000 



23, 860, 000 

 10, 630, 000 



4, 750, 000 



Per 



cent 



75 



25 



115 



110 



Board 

 20, 232, 000 



4, 300, 000 

 2, 110, 000 



527, 000 



Num 



her 



192, 000 



56, 000 

 28,000 



14, 000 



Linear 

 8, 634, 000 



5,965,000 



1, 595, 000 



475, 000 



Board 



feet 



34, 626, 000 



11, 945, 000 



Poles; mature in 80 

 to 120 years 



Keproduction; ma- 

 ture in 120 to 160 

 years 



4, 445, 000 

 1, 422, 000 



Bums not restock- 

 ing 























Total 



93, 520 



63, 551, 000 



799, 000 



50, 752, 000 





27, 169, 000 



290, 000 



16, 669, 000 



52, 438, 000 











1 From scattered, overmature trees in these stands. 



