PLANTING STOCK PERFORMANCE - SITE AND RGP EFFECTS

Douglas-fir [Pseudotsuga menziesii var glauca (Beissn.) France], inter ior spruce [Picea glauca Moench (Voss), Picea engel mannii (Parry) and their naturally occurring hybrids] and lodge pole pine (Pirry) contor ta Dougl.) seedlings were planted on several forest sites in south cen tral British Columbia. At planting, root growth potential (number of n ewly elongated roots longer than 10 mm per seedling) was determined. T rees were assessed for survival and height for at least five years. Su rvival of Douglas-fir and growth of all three species was affected by planting site, probably reflecting moisture and growing season tempera ture differences among sites. High (>70%) survival, but not total heig ht or mean annual relative growth rate was associated with root growth potential levels greater than 10 new roots per seedling in interior s pruce and lodgepole pine. Survival and growth of Douglas-fir were not related to root growth potential. Fertilization of interior spruce see dlings at planting decreased survival 18% over seven growing seasons, and did not affect growth of surviving seedlings.