228 



R. J. STEINHOFF 



Figure 11. A 65-year-old, thinned, western white pine stand, 

 Deception Creek Experimental Forest (U.S. Forest Service photo) 



DISCUSSION 



Western North America has a variety of white pines with rather broad 

 geographic ranges. It would seem, therefore, that most of these species 

 would be adapted to quite a wide range of conditions but this is not 

 necessarily so. Much of the variation which might be expected to accom- 

 pany latitudinal displacement within species probably is offset by 

 compensating elevational shifts. Climatic variables such as length of 

 growing season and amount of annual precipitation are often quite similar, 

 even between widely separated stands. 



Several of the species grow on the same sites, especially near the 

 extremes of their ranges. For example, western white pine and whitebark 

 pine grow together in several areas as do whitebark and limber pines. 

 Sugar pine and western white pine grow together in Oregon and California. 

 Western white, whitebark, limber, and foxtail pines grow within a few 

 yards of one another in the Sierra Nevada Mountains, and sugar pine grows 

 only a few miles away. 



SUMMARY 



The foxtail pines comprise two species both of which grow in western 

 North America. Pinus halfouvixia is restricted to two areas in California 

 while P. aristata is widely distributed. Neither species is commercially 

 important but both have high esthetic value and may be useful for water- 

 shed protection or avalanche control. 



