Rehfeldt, G. E. Components of adaptive variation in Pinus contorta from the Inland 

 Northwest. Research Paper INT-375. Ogden, UT: U.S. Department of Agriculture, 

 Forest Service, Intermountain Research Station; 1987. 11 p. 



Genetic variation among 83 populations of Pinus contorta from the Northern Rocky 

 Mountains of the United States was studied with 7-year-old trees planted in three con- 

 trasting environments. Analyses of nine traits reflected adaptation of populations to 

 the biotic and abiotic environments and revealed clinal patterns of differentiation that 

 were elevationally steep but geographically gentle. Regression models present adap- 

 tive landscapes that mirror elevational and geographic gradients in climate. 



KEYWORDS: genetic variation, population differentiation, microevolution, Pinus 

 contorta 



