The abundance and diversity of pollinators generally decrease with urbanization. On the other hand, pollinator communities observed in different urban green spaces - parks, residential gardens, cemeteries - show greater species diversity. In fact, urbanization may attract some species - such as those nesting in cavities - more than others - such as those nesting in the ground.
Green roofs are particular environments because they are exposed to sun and wind as well as extreme drought and high water flows. Certain green roofs are home to an interesting biodiversity of invertebrates including rare species of spiders, coleopteran (e.g. beetles) and hymenopteran (e.g. wasps). The diversity of species stems from several factors including plant composition and coverage, substrate thickness, presence of nesting structures (e.g. trees, existing burrows), neighbouring habitats, etc. Some green roofs designs incorporate these factors to foster greater biodiversity of insects.
Green roofs are part of the green infrastructures whose large-scale implementation is anticipated to reduce the impacts of urbanization and climate change in Quebec. Studies suggest that they may play a role as a refuge for entomological biodiversity or as part of a larger ecological network. To design green roofs accordingly, it is important to understand the factors that promote greater insect biodiversity on green roofs, including pollinators. This study aims to identify the characteristics of roofs that support the presence of pollinators. This knowledge will provide essential information to orient green roof projects.
This project is made possible through a grant awarded by the Quebec Centre for Biodiversity Science. It also serves the objectives of the working group on the determinants and management of urban biodiversity.
- Scientific direction
- Valérie Fournier, Professor of Entomology, Department of Plant Science, Univerisity Laval's faculty of agriculture and food sciences
- Danielle Dagenais, CPEUM's Associate Researcher and Associate Professor, School of Landscape Architecture, University of Montreal
- Research agent
- Nathalie Roullé, Doctoral candidate, Department of Biological Sciences, UQAM