Patterns and processes of exotic plant invasions in Riding Mountain National Park, Manitoba, Canada

dc.contributor.authorOtfinowski, Rafael
dc.contributor.examiningcommitteeTenuta, M. (Soil Science) Turkington, R. (University of British Columbia, Botany) Van Acker, R. (University of Guelph, Plant Agriculture) Wilmshurst, J. (Biological Sciences)en
dc.contributor.supervisorKenkel, N. C. (Biological Sciences)en Sciencesen_US of Philosophy (Ph.D.)en_US
dc.description.abstractInvasive exotic species threaten the biodiversity and function of native ecosystems. Existing models, attempting to predict and control successful invaders, often emphasize isolated stages of in their life history and fail to formalize interactions between exotic species and recipient environments. In order to elucidate key mechanisms in the success of select invaders, I investigated the role of dispersal, establishment, proliferation, and persistence in their threat to natural areas. Focusing on Riding Mountain National Park, Manitoba, Canada, I integrated the native climatic range and biological traits of 251 exotic vascular plants reported inside and outside the park. Based on their climatic range in Europe, 155 among 174 exotic plant species absent from the Park were predicted to establish within its boundaries; among these, 40 clonal perennials were considered the highest threat to the Park’s biodiversity. Focusing on smooth brome (Bromus inermis Leyss.), a Eurasian perennial, threatening the structure and function of native prairies throughout the Great Plains, I extended my research to investigate the role of dispersal, establishment, proliferation, and persistence in characterizing its threat to the endemic diversity of northern fescue prairies, protected within Riding Mountain National Park. Patterns of smooth brome invasions were contingent on the type of propagules dispersed. The shallow dispersal gradient of individual florets combined with the steeper gradient of panicles and spikelets suggested that smooth brome is capable of simultaneously invading along dense fronts as well as by establishing isolated foci. While low correlations between the number of dispersed seeds and their recruitment suggested post-dispersal transport, seedling establishment remained contingent on prairie diversity. Seedling biomass increased with declining plant diversity, however, its impact depended on the availability of soil nitrogen. As a result, disturbed areas, preserving the root function of native plants, resisted smooth brome establishment. Even though low nitrogen contributed to a decline in seedling biomass, physiological integration between ramets facilitated their vegetative proliferation in low resource environments. Despite its rapid establishment and proliferation, smooth brome productivity declined at the center of invading clones. Although field and greenhouse observations failed to implicate soilborne pathogens, reasons for the observed decline remain unresolved. My research demonstrates that while Riding Mountain National Park and other natural areas in western Canada will continue to be impacted by exotic plants, integrating key stages in their life history provides an important conceptual framework in predicting their threat to natural areas and prioritizing management.en
dc.description.noteOctober 2008en
dc.format.extent7006050 bytes
dc.identifier.citationOtfinowski, R., N. C. Kenkel and P. M. Catling. 2007. The biology of Canadian weeds. Bromus inermis Leyss. Canadian Journal of Plant Science 87: 183-198.en
dc.identifier.citationOtfinowski, R., N. C. Kenkel, P. Dixon and J. F. Wilmshurst. 2007. Integrating climate and trait models to predict the invasiveness of exotic plants in Canada’s Riding Mountain National Park. Canadian Journal of Plant Science 87: 1001-1012.en
dc.identifier.citationOtfinowski, R, N. C. Kenkel and R. C. Van Acker. 2008. Reconciling seed dispersal and seedbank observations to predict the invasion patterns of smooth brome (Bromus inermis) in a northern prairie. Invasive Plant Science and Management DOI: 10.1614/IPSM-08-066.1en
dc.identifier.citationOtfinowski, R. and N. C. Kenkel. 2008. Clonal integration facilitates the proliferation of smooth brome clones invading northern fescue prairies. Plant Ecology. DOI 10.1007/s11258-008-9428-8en
dc.rightsopen accessen_US
dc.subjectbiological invasionsen
dc.subjectrisk analysisen
dc.subjectclimate-matching modelen
dc.subjectbiological traitsen
dc.subjectsmooth bromeen
dc.subjectBromus inermisen
dc.subjectplant dispersalen
dc.subjectinverse power functionen
dc.subjectspatial patternsen
dc.subjectinvasion resistanceen
dc.subjectcommunity diversityen
dc.subjectclonal proliferationen
dc.subjectphysiological integrationen
dc.subjectsoilborne pathogensen
dc.subjectnegative feedbacken
dc.subjectnatural areaen
dc.subjectnorthern fescue prairieen
dc.titlePatterns and processes of exotic plant invasions in Riding Mountain National Park, Manitoba, Canadaen
dc.typedoctoral thesisen_US
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