THE AUTHOR 



G. E. REHFELDT is a plant geneticist at the Intermountain 

 Research Station's Forestry Sciences Laboratory in 

 Moscow, ID. He has been studying the ecological and 

 quantitative genetics of Rocky Mountain conifers since 

 1968. 



RESEARCH SUMMARY 



Genetic variation among 83 populations of Pinus con- 

 torta from the Northern Rocky Mountains of the United 

 States was studied with 7-year-old trees planted in three 

 contrasting environments. Analyses of nine traits reflected 

 adaptation to biotic and abiotic environments and revealed 

 clinal patterns of differentiation that were elevationally 

 steep but geographically gentle. In particular, populations 

 from relatively mild environments had the highest growth 

 potential but suffered the most snow damage when 

 planted at high elevations. Populations from high eleva- 

 tions were most susceptible to needle cast when trans- 

 ferred to low elevation. And populations transferred the 

 greatest geographic distances suffered the most from 

 infestations of mites. Regression models present adaptive 

 landscapes that mirror elevational and geographic 

 gradients in climate. 



Intermountain Research Station 

 324 25th Street 

 Ogden, UT 84401 



