| dc.description.abstract | Nitrogen (N) is critically important for plant growth and development. The
objective of this thesis is to examine how different rates of Nitrogen affect the seedling
growth in black spruce (Picea mariana Mill.). This paper investigates the effects of
nitrogen fertilization on seedlings growth for blcak spruce (Picea mariana Mill.) with a
range of fertilizer applications from 10 to 360 μmol mol-1N. The experiment was carried
out in 2 environmentally controlled greenhouses in the Forest Ecology Complex at the
Thunder Bay Campus of Lakehead University. After four months the fertilizer
application, the seeding height, root collar diameter, and the height to diameter ratio
were evaluated. Seedling growth was significantly affected by the rate of Nitrogen
fertilizer, with an optimum rate at 150% nitrogen rate. The average heights were 38.31,
51, 46.01 43.93 and 47.81cm, respectively, for the 10, 150, 220, 290 and 360 umol mol-
1 N treatments. The nitrogen treatments also affected the variability of RCD but the
patterns of variation were different from that of seedling height. Both seedling heights
and Root collar diameter decreased after 150 umol mol-1 N, which indicating that
saturating plant with high nitrogen levels, however, does not improve plant growth. | en_US |
