Sager, Eric PS
Naturalizing Naturalization: Accounting for Naturalization in Ecology and Ecological Management
This thesis presents a case of the aquatic plant species Fanwort (Cabomba caroliniana) significantly naturalizing in Kasshabog Lake in bays where it had been invasive. This significant naturalization presents major implications for invasive species management and invasion biology because the naturalization of invasive species is a phenomenon that has been largely omitted from study within ecology. There are several reasons for this: 1) the most used definition of the term naturalization within invasion biology categorically excluded the sense in which naturalization refers to community integration; 2) the most cited frameworks that have been created and used to describe and study biological invasions have no conception of invasive species naturalization; 3) boundary work has been conducted to exclude consideration of the naturalization of invasive species. Incorporation of an understanding of naturalization into science and management of biological invasions will make our understanding of them more complete.
Author Keywords: Ecological Restoration, Invasion Biology, Invasive Species, Naturalization
The biogeochemical effects of non-industrial wood ash application on ecosystem regeneration in central Ontario
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