Growth of Interior spruce seedlings on forest floor materials

• Main Author: Heineman, Jeanette Lynne
• Language: English
• Published: University of British Columbia 2010
• Online Access: http://hdl.handle.net/2429/29871

On a site with a high water table and thick forest floor near Smithers, B.C., two year-old Interior spruce (Picea glauca (Moench) Voss X Picea engelmanni Parry) container seedlings were outplanted onto mineral soil, H-layer material, F-layer material, and rotten wood. Large and small screef sizes were utilized. Temperature and volumetric water contents of the various substrates were monitored over the 1989 growing season, and fertilization with NH₄NO₃ was carried out at the beginning of the 1990 growing season. Destructive sampling of the seedling population took place in August 1989 and August 1990 in order to determine height, root collar diameter, root mass, shoot mass, total seedling mass, and shoot to root ratio. Foliar N concentrations were also determined in late August 1990. Differences in height and diameter for the seven screef size/substrate treatments were not significant, but the organic substrates produced seedlings of greater root, shoot, and total seedling mass than did mineral soil. Greater seedling mass was correlated most strongly with higher substrate temperature, and to a lesser extent with lower soil moisture content, as well as with higher foliar N concentration. There were no significant differences in survival between the treatments. Seedlings growing in the organic substrates had higher foliar N levels, and fertilization improved growth for all parameters. It is concluded that on sites such as this, better growth results can be achieved by planting Interior spruce seedlings high above the water table in F-layer material, where conditions are warmer and drier, than by making deep screefs down to more traditionally acceptable planting substrates such as mineral soil or even the well decomposed H-layer material. === Forestry, Faculty of === Graduate