Ponderosa Pine in the Southwest 



347 



virgin stands remain. The growth and 

 yields are low. 



The products cut in the past have 

 been low in price, and private owners 

 therefore have had little incentive to 

 take positive management action to 

 maintain or increase productivity. Re- 

 search on the public lands to deter- 

 mine potentialities has been limited. 

 More data on sound management are 

 needed ; so is an effort to find new and 

 profitable uses for the few high-grade 

 products the area can furnish. The ex- 

 tensive area of the type would indicate 

 adequate supplies of material to meet 



present and future needs. It should be 

 the aim to keep this large land area 

 producing successive crops of essential 

 wood products, since the forest is, all 

 things considered, the highest use of 

 the area. 



QUINGY RANDLES,, formerly in 

 charge of timber management in the 

 Southwestern Region of the Forest 

 Service, is now retired. He holds de- 

 grees from the College of Wooster in 

 Ohio and the University of Michigan. 

 He started work with the Forest Service 

 in 1911. 



PONDEROSA PINE IN THE SOUTHWEST 



C. OTTO LINDH 



From train or highway, the traveler 

 in Arizona and New Mexico sees tree- 

 less mesas, deserts, some scattered 

 woodlands, century-old habitations, 

 the white gold of the sunshine, and the 

 bright blue of the cloudless sky. He 

 does not see, far back from the main 

 routes, the plateaus, the high mesas, 

 and the slopes that are clothed with 

 valuable forests. 



In Arizona and New Mexico are 

 6,280,000 acres of forest land from 

 which trees can be harvested. About 4 

 million of these acres are in national 

 forests, a million in other Federal 

 ownership and the Indian reservations, 

 and a million in the ownership of 

 States and counties and individuals. 



The most valuable tree in the South- 

 west is the ponderosa pine, which in 

 volume accounts for 88 percent of the 

 total of all commercial species and 

 produces 90 percent of the 375 to 400 

 million board feet of lumber cut each 

 year. Unbroken stands extend for miles. 



Ponderosa pine grows where the an- 

 nual precipitation is 18 to 24 inches 

 less water than any other large com- 

 mercial tree requires. In the South- 

 west it grows at elevations of 6,500 to 

 8,000 feet, which correspond to the 

 18- to 24-inch precipitation zone. At 



lower elevations it is found in mixture 

 with junipers, pinyons, and oaks. In its 

 main range, pure stands are the rule. 

 On cool, northern slopes and at upper 

 elevations, it is mixed with Douglas- 

 fir, spruce, limber pine, and white fir. 

 Small aspen groves are not unusual 

 throughout the type, except at the 

 lower elevations. Disregarding ex- 

 tremes, ponderosa pine stands contain 

 5,000 to 15,000 board feet an acre. 

 Over large areas, in the main range, 

 stands average about 10,000 board feet 

 an acre. 



The virgin stands of ponderosa pine 

 in the Southwest are unusually de- 

 cadent or injured. Western red rot re- 

 duces gross volumes by 15 to 25 per- 

 cent or more on some rocky ridges. 

 Mistletoe, the slow killer, is wide- 

 spread. The Cronartium rust is found 

 throughout the type on individual 

 trees here and there. Bark beetles are 

 not unusually serious and seldom reach 

 epidemic proportions, except that sev- 

 eral species of Ips and Dendroctonus 

 make serious inroads in small areas 

 during cycles of dry weather. Light- 

 ning causes the most damage and high- 

 est mortality. If it does not kill the 

 struck tree outright, it leaves a long 

 open wound, into which disease or- 



