Department of Biology
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Browsing Department of Biology by Subject "Alliaria petiolata"
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Item Open Access Characteristics of expanding and stable populations of garlic mustard in Carolinian parks(Heritage Resources Centre, University of Waterloo, 2002) Firanski, J. Carrie; Falkenberg, Nancy; Koh, Saewan; Bazely, DawnGarlic Mustard (Alliaria petiolata) is a short-lived monocarpic perennial introduced to North America in 1868 which reached Canada in 1879. It was first introduced to Point Pelee National Park in 1969 and Rondeau Provincial Park in the 1980s. Both parks have long histories of human-induced disturbance, with most recently high deer grazing pressure. We show that garlic mustard has become (Point Pelee NP) and is becoming (Rondeau PP) a predominant understorey herb from 1994 to the present, and that the two parks are in different phases of colonization. Our research suggests that the garlic mustard population at Point Pelee has stabilized while the Rondeau population is continuing to expand. We found a significant negative relationship between species diveristy and garlic mustard density for both of the parks. However, it is unknown whether garlic mustard is supressing native herbaceous species diversity, or whether low diversity is an outcome of the intense long-term grazing pressure exerted by deer on the native species. Interestingly, the garlic mustard populations at both parks have alternate years of high and low flowering densities, driven by intraspecific density effects. This may expalin the lack of negative association in garlic mustard density and native diversity in some years. Further research will include experiments with native species transplants into garlic mustard dominated sites to determine competitive interactions, and analysis of changes in distribution throughout the transects to determine rate of spread of expanding garlic mustard populations at Rondeau.Item Open Access Using a data synthesis approach to generate novel results for ecosystem recovery in deer-affected forests(2011-04) Tanentzap, TracyOvergrazing by white-tailed deer (O. virginianus) has been an ongoing problem in Rondeau Provincial Park since the turn of the century. Since the recent reintroduction of annual culls by park officials, deer densities have declined but the extent to which this control has been effective in restoring plant communities remains to be seen. Such research may only be conducted by synthesizing long-term data sets, dating back to the establishment of artificial exclosures in the park and commencement of culls, and producing novel information. It was determined that T. grandiflorum populations within the park are still in the process of recovery, even following eighteen years of experimental exclosures. Thus, recovery from recently reduced deer populations is still underway and occurring at a slow rate. It is also believed that high deer herbivory aids in the spread of invasive species, however this was not found to be the case in Rondeau. Spread of invasive A. petiolata is diminishing in intensity and was found to have little effect on species richness in affected areas. These results illustrate the utility of data synthesis principles and practices in long-term ecological studies and stress the importance of process metadata and digital data repositories in furthering such a field.