Consequences of Plant Invasion in a Peri-urban Ecosystem: A Case Study of the Invasive Vine Vincetoxicum rossicum
Year: 2018
Type: dissertation
Abstract: The impacts of non-indigenous invasive plant species on peri-urban ecosystems are known to be highly variable and are the subject of much debate within the discipline of invasion ecology. Yet, there is a desperate need to quantify those impacts, investigate the potential for control and engage with the stakeholders that are affected by invasion. Using the invasive species Vincetoxicum rossicum in and around Canada’s Rouge National Urban Park, I 1) quantify its impact on biodiversity and ecosystem functionality, 2) examine the effectiveness of a bio-control agent (Hypena opulenta) in reducing the reproductive ability of V. rossicum in different light environments, 3) examine the ecological significance of rare and functionally unique species, and whether or not those species are disproportionately affected by V. rossicum invasion, and 4) examine stakeholder valuation of ecosystem services that are threatened by the spread of V. rossicum. I show that V. rossicum invasion is associated with significant declines in plant biodiversity and the impairment of several ecosystem functions including aboveground biomass production, floral resources and the diversity and abundance of local pollinators. I then show that, contrary to previous laboratory work, defoliation of V. rossicum by H. opulenta in shade conditions results in significantly greater seed production via a compensatory growth response. Then, through a combination of modelling simulations and empirical data collection I show that there are no general trends regarding the ecological significance of rare and/or functionally unique species, but that some rare plant species are ecologically important in the face of invasion. Then, by employing stakeholder analysis, I show that park-user knowledge of V. rossicum, operationalized as “ecological engagement”, results in significantly greater valuation of ecosystem services, but also that there is substantial neutrality and disagreement about the ecological impact of V. rossicum among stakeholders. As V. rossicum invasion is undoubtedly having negative impacts on ecosystem functions and services, this work points to the need for continued research on the potential for control options. Furthermore, given that the spread of V. rossicum is prolific in urban environments, conservation practitioners would do well to develop more effective communication strategies that can engage local stakeholders.
Source: TSpace (University of Toronto)
Author: Stuart W. Livingstone
Language: English
Subfield: Nature and Landscape Conservation
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3012488765