The effects of competition on underplanted juvenile white spruce in fill blocks in northern Alberta

Abstract

This paper examined the effects of competition on juvenile white spruce growth planted in the understory of lodgepole pine on a mixedwood boreal site. Growth and success of planted white spruce seedlings were investigated under four young canopy densities. Seedlings showed no statistically significant differences in total height growth or total root collar diameter between any density. The mortality rate was found to be extremely low (3%). This finding supports the suggestion low mortality rates of underplanted species is in part the result of protection from the overstory canopy. The findings of this study can be applied to similar situations where white spruce is planted beneath an established or establishing canopy. A review of applicable literature regarding light availability and competition from shading is included.