Title: Genetic Variation and Phenotypic Stability among Three Elevational Sources of Coastal Douglas-fir from Southwest Oregon. Abstract approved: Signature redactedforprivacy

This study had three objectives: (1) to determine the degree to which within-source genetic variation and genetic correlations differ among elevational sources of Douglas-fir CPseudotsuga menziesii (Mirb). Franco var. menziesii]; (2) to ascertain the degree to which phenotypic stability differs among and within elevational sources; and (3) to compare the relationships among four measures of stability (variance, regression slope coefficient, deviation from regression and ecovalence). To accomplish the objectives seeds were collected from 10 parent trees in three populations from each of three elevations. Nine traits were measured on two-year-old seedlings grown in four test environments that facto'rially combined heated and unheated air and soil. Results support the hypothesis that the magnitude o