Arizona republican., 1904-07-18
FORESTSOF ARIZONA
A Study of the Great San
 Francisco Reserve
An Interesting Document Which Has Lately Been Issued by the United States Geological Survey.

Washington, July IA study or forestry seems to be especially esteem ed in countries where there are no longer forests to study. Realizing how vital to the welfare of a nation IS the preservation of its forests, the United States is making an endeaVor 10 study and improve the forests of this country while there is yet time to preserve them. In furtherance of this work the United States geological survey has just published Professional Paper No. 22 which bears the title Forest Con ditions in the San Francisco Mountains Forest Reserve. Arizona" This pa per embo5ies the results of the inves- tigations made during 1901 and 1902 by 1 Messrs. John B. Leiberg, Theodcre F. Rixon and Arthur Dodwell, and Is prefaced by an introduction written i by Mir F. c. Hummer, which is par ticularly interesting.
 i The San Francisco Mountains forest reserve comprises portions of the bread summit and slopes of an elevated tract of land in north-central Arizona, which 1 includes the southern part of the Colo rado plateau. The northern part of { the area is dotted by several hundred volcanic cones and the. southern part Is gashed by numerous deep canyons. Ire altitude of the region raTges from i 3509 feet at Oak creek in the southwest ern cOrtion. to 12.794 feet at the sum- init of San Francisco 2eak.
 ! Among the con!ferous trees in the reserve the yellow-pine constitutes over 9 per cent of tie entire fGre45 The aspen takes first rank among the board-leafed species but has close competitor in the cak. The chief lumber tree at present is the yellow pine, which is extensively cut and fur niShcs all of the mill timber sawed, used in, and exported from the region. It's average total height is S5 feet, with 1 about 10 feet of clear trunk. The di- ameter average is IS inches. which cor responds to an age of 1S0 years In 1 the 2.500 acres of forest area eXamin- cd. 2.743.55S.000 feet B. M. of standing i timber were found. which gives an av- craze of only 33T7 feet B. M. per acre IL is evident that the yellow Iine stands, even where entirely untouchc by the ax. do not carry an average ol more than 10 per cent of the timber they are capable of producing Tn condition is chiefly attributable to th- numerous fires which have swept ovei the reGicn within the last two hun dred years. destroying seeding and saGling growth.
 The chief agencies through whicl the forests in the reserve suffer de stcuction are cutting. grazing and fire logging operations have been carried on in most Of the central foirested areas that are tributary to railroads The forest has been culled CT cut from NS,S45 acres. The timber cut CT these tracts has been convei ted mtc tie, stull or round mining timber anc saw logs.
 Grazing. especially sheep herding is ruinous to the seeding growth of 6 young forest. Sheep are especially fond of the young aspen, which spring. up as the first restockage on the non forested park lands at the base anC on the slopes of San Francisco noun tains. It was found that the destruc. tion of seedlings on any partieuia tract of land ranged from 50 per cen to total after a single passage ovel such ground by 1000 head of sheep
 Fires have been of frequent occur renee in all portions of the reserve
 The badly burned areas. on whicI the destruction has been SO per cen or more, aggregate 6,790 acres Tn, origin of fires in recent years may. il part. be asc1ibed to the carelessnes
 Of sheep herders, in part to spark
 from engines on the Atchiscn, Topek; and Santa Fe railroad, but by ia the larger number of fires are due {; lightning, and this cause has, of course always operated. Sections exist O,
 which 50 per cent of the mature yellov
 pine has been either wholly or in par
 Billed by lightning strokes.
 WEATHER TOnAN