Turkish red pine (Pinus brutia Ten.) at an age of six years, exhibited significant inter-and intra-population variation in its elevational distribution in the Antalya region in southern Turkey. The differences among the six populations and among families within populations were significant for total height, number of annual growth cycles, and crown form at four common garden plantations established along an elevational transect in the region.

      Heights of trees from population M,  mid–elevation seed source (486m.) , were the largest at all plantation sites. At the highest site (850 m.) , however, it did not differ significantly from most other populations. Population K from a higher seed source (900 m.), and population B from  mid–elevation source ranked second and third in height at three of the four common gardens. Trees from two low–elevation sources were shorter than the plantation mean at the highest site.

      The study demonstrated that genetically superior families exist within populations for the following characteristics: total height, number of annual growth cycles, crown form and number of lateral branches per unit length of main stem. Some families were consistently superior at more than one plantation sites for one or more of these characteristics. Among  the 60 families studied, those coded 2,3,5,6 and 10 from population M,5,6 and 7 from K, 1 and 9 from B, and 8 from population S showed superior growth and higher adaptational plasticity at least on three plantation sites.

      Better performances of populations from mid-elevation seed sources at low and mid-elevation plantation sites were explained by the theory of “ non-optimality of local races” as discussed by Namkoong. Based on the present study and similar works on other species, we tentatively proposed four distinct breeding zones and seed transfer guidelines for Pinus brutia in the Antalya region.  Definite borders for the proposed breeding zones can subsequently be determined upon the availability of additional information such as genotype x environment and genotype x time interactions during the later stages of this and other progeny and provenance trials on the species.

      We found that heights of nursery seedlings alone were not a good indicator of tree heights in subsequent years. Total height of trees from the third to the fifth growing season showed significant linear correlation with total height at six years of age. Apparently, both genotypeXtime and genotypeXenvironment interactions play important roles in the developmental genetics of Pinus brutia.

      We estimated that if seeds of selected populations of this species are used in reforestation programs, trees at age six will be at least 15 percent taller than trees derived from “average” seed sources. Moreover, if seeds of selected families are used, the first generation of genetically improved trees will be at least 29 percent taller than those from commercial seed lots. With the inclusion of some basic silvicultural treatments such as brush control, heights of six-year old trees from selected parents will be about 70 percent taller than those we have on our commercial plantation sites today. These results suggest that genetic improvement of P. brutia will contribute substantially in meeting the growing demands of wood and cellulose products in the near future, forest genetics and tree improvement studies must be accelerated on P. brutia.