Black spruce regeneration in Kalmia dominated sites: Effects of mycorrhizal inoculation and forest floor mixing.

摘要

There can be a shift in vegetation from black spruce (Picea mariana Mill.) forests with the ericaceous shrub Kalmia angustifolia L. (Kalmia) in the understory to ericaceous dominated heath in some areas of Newfoundland. This occurs on low to medium fertility sites after forest fire, insect defoliation, or clear-cut harvesting. Kalmia spreads rapidly with the concomitant failure of black spruce regeneration. This is a serious and widespread problem for the forest industry, and for protected area management when human interventions to natural disturbance cause the formation of Kalmia heath. The objective of this thesis was to test two alternate methods of enhancing black spruce regeneration in Kalmia dominated sites. I examined the growth response and foliar nutrient concentration of black spruce seedlings inoculated with the ectomycorrhiza (EM) Paxillus involutus (Batsch. Ex Fr.) Fr, planted in mechanically-mixed forest floors dominated by Kalmia . Changes in soil physical and chemical properties following mechanical mixing (tilling) of the forest floor horizon were also studied. The experiment was conducted over two growing seasons in Kalmia dominated sites resulting from heavy insect defoliation by spruce budworm and natural fires in Terra Nova National Park, Newfoundland. (Abstract shortened by UMI.)