The effects of killing a low-volume residual overstory on growth of advance natural regeneration in North Idaho were assessed. Killing this overstory had little effect on subsequent growth of advance regeneration regardless of the basal area killed. Growth of regeneration following release was affected by competition from other advance regeneration and competition from brush. Height-growth response was negligible when density of either advance regeneration or brush were high. Residual tree killing was associated with improved crown vigor of regeneration where residual overstory basal area was high. Height growth of advance regeneration following residual tree killing was highly correlated with prerelease height growth and current crown vigor of advance regeneration. West. J. Appl. For. 7(3):78-81.

A study of nitrogen fertilization response in thinned and unthinned stands of grand fir (Abies grandis) and Douglas-fir (Pseudotsuga menziesii) in northern Idaho showed that the application of one urea nitrogen treatment applied at a rate of 200 lb N/ac resulted in a significantly higher average basal area growth over a 6-year post-treatment period. Nitrogen fertilization also resulted in a significant height increment increase over the same period. Fourteen years after treatment, fertilization had increased average tree size, in terms of total cubic volume, by 14% in unthinned and by 23% in thinned stands. A comparison of thinned and unthinned stands suggested an increase in tree size (>300%) over the same period without significant reduction in average total cubic volume per acre. Patterns of stand development were altered by nitrogen fertilization. West. J. Appl. For. 4(2):54-57, April 1989.