Ecotypic Differentiation in Populations of Pinus monticola in North Idaho -- Myth or Reality?

Abstract

Full-sib families representing 12 populations of P. monticola were compared to assess local differentiation of populations in northern Idaho. Populations represented north and south aspects at 3 elevations (950, 1175 and 1400 m) in each of 2 drainages. Tests of 6-yr-old seedlings growing in 2 contrasting environments revealed little or no differentiation among populations, genetic variation among families within populations and large environmental effects on growth and development. Adaptation of P. monticola to variable environments may be governed more by phenotypic plasticity than by selective differentiation.