Biodiversity is declining across the globe, and human-driven climate change and land-use change are among the primary drivers of this loss. Understanding the mechanisms causing declines is critical for developing effective conservation and management strategies which will not only slow biodiversity loss, but reverse it. This is relevant for virtually all species on the planet, but given the ecosystem services that they provide, pollinators are an especially important group in which to study this. Among the wild pollinators native to North America and Europe, bumblebees (Bombus) are a particularly important and beautiful group. In this thesis, I identify how climate change and land-use change interact to influence population and community change in North American and European bumblebees, and I explore the potential role of protected areas in mitigating declines. I find that climate change has increased local extinction risk for bumblebees by exposing them to temperatures beyond their historic tolerances, and I introduce a broadly applicable method which improves prediction of this climate change-related risk (Chapter 2). Examining the interactions between climate change and land-use change shows that the risk from increasing temperatures and temperature extremes is worse in historically degraded areas, and that climate change and land-use change may be driving biotic homogenization in bumblebee communities. Yet, landscape-scale patterns suggest that human land-use can be managed to have minimal, or even positive, effects on pollinators (Chapter 3). In the face of these global pressures, protected areas represent one way to conserve species. I find that increasing the amount of protected area in a region, regardless of size or management category of the protected areas, is related to reduced local extinction risk for bumblebees across North America and Europe. This benefit is especially strong in areas with high human land-use, highlighting the importance of protected areas in highly human-dominated landscapes (Chapter 4). The work within my thesis improves our understanding of how climate change and land-use change drive shifts in species and communities, and can inform on the effectiveness of specific conservation actions from gardens and urban greenspaces, to Other Effective Area-Based Conservation Measures (Chapter 5).
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/43099 |
| Date | 10 January 2022 |
| Creators | Soroye, Peter |
| Contributors | Kerr, Jeremy Thomas |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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