Response of Grand Fir, Western Hemlock, Western White Pine, Western Larch, and Douglas-Fir to Nitrogen Fertilizer in Northern Idaho

摘要

Two study areas were used to assess the response of mixed, young, coniferous forests to nitrogen (N) fertilizer in the form of urea. Significant (P<0.05) responses in diameter growth to fertilization were noted at one of the study areas. Significant differences were detected between the height growth means in both study areas. Differences between the height and diameter growth means for the 200 lb N per acre (224 kg N per ha) treatment and the 400 lb N per acre (448 kg N per ha) treatment were not significant. When each species was analyzed separately only grand fir (Abies grandis) and Douglas-fir (Pseudotsuga menziesii) had a significant response to fertilizer application.