GROWTH-PERFORMANCE AND REACTION TO BIOTIC AND ABIOTIC FACTORS OF DOUGLAS-FIR PROGENIES (PSEUDOTSUGA-MENZIESII [MIRB] FRANCO)

Seed of 24 progenies of Douglas fir (Pseudotsuga menziesii [MIRB.] FRA NCO) from 7 states of the USA and of 1 progeny from Mexico collected w ithin the natural range of the species was sown in 1963. In spring 196 6 a field trial was established in the forest district of Nordhorn, no rthwestern Germany, as part of the Emsland afforestation program to te st the suitability of Douglas fir progenies on former agricultural lan d. In the field trial several traits were measured or assessed regardi ng growth performance, susceptibility to biotic and abiotic agents, an d volume production after 32 years of growth. Regarding these characte rs the provenances show a great variation and can be divided into at l east 6 main groups (clusters). At the age of 32 the progenies from coa stal Oregon would have produced in a pure stand 220 m(3)/ha. The perfo rmance of the Douglas fir progenies was compared also with. tree speci es regenerated naturally in the field trial.