Effect of nitrogen fertilization on ring width, proportion of latewood and specific gravity of black spruce
University of New Brunswick
The variation of ring width, proportion of latewood and specific gravity were studied in an 80-year-old black spruce (Picea mariana (Mill.) B.S.P.) stand, fertilized 15- years ago in 1961 with 400 pounds of nitrogen, as urea, per acre. The variations found with height, within the trees, before and after fertilization and between fertilized and control trees were similar. The increase in ring width was still evident 15-years following fertilization. The proportion of latewood increased, possibly due to an increase in the quantity of transition latewood, while specific gravity decreased in the 10-year period following fertilization. Both values approached those of the pre-treatment in the (1972-1976) growth period.