Decades of sulphur and nitrogen deposition acidified forest ecosystems across northeastern North America causing declines in pH and exchangeable base cation concentrations, negatively affecting biota. To assist natural recovery, researchers are investigating using alkaline soil amendments such as wood ash. However, much remains unknown about its use. This thesis evaluated the effects of non-industrial wood ash application (between 0 – 12 Mg ha-1) on soil chemistry, understory vascular plant communities and sugar maple (Acer saccharum Marsh.) regeneration in central Ontario. Wood ash increased soil pH and concentrations of calcium, magnesium and several metals. Vascular plant species abundance, richness, and diversity exhibited no consistent treatment effect. Sugar maple seedling survivorship was adversely affected by wood ash applications > 4 Mg ha-1, while growth was unaffected. These results support related research regarding the ability for wood ash to increase soil pH and base cation status but raises uncertainty regarding consequences for vascular plants.
Author Keywords: Acer saccharum, Acid deposition, Ecosystem regeneration, Soil amendment, Understory vegetation, Wood ash