| Motives:
Since the 1950s, pollinators’ species are in decline worldwide. In Sweden, drastic decreases were found in bee diversity over the last 70 years. Although many plausible drivers have been hypothesized and the causes of this phenomenon remain debated the decrease in flowers in agricultural landscape and pathogen incidence likely play a major role. Interactions between these drivers have yet to be investigated. Insufficient floral resources are likely to increase competition and interactions between pollinators and enhance the spread of pathogens. However, very little is known about how the amount of floral resources in the landscape, and in particular the increase in mass flowering crop cultivation, affect pathogen prevalence in major pollinator groups, bumblebees and honeybees.
Objectives & Methods:
In the proposed project, we will use state of the art molecular tools to link the amount of floral resources in agricultural landscapes in Skåne to bumblebee and honeybee pathogen incidence by analyzing around 900 pollinator pollen data collected in 2019. The Oscar and Lili Lamm Memorial Foundation research grant will support the expenses for pollen & bacterial barcode analyses and pathogen assays. Specifically, we want to test the hypothesis that increasing mass flowering crops area in the landscape will decrease pathogen prevalence in the pollen collected by these pollinators due to decreased competition between pollinators. This research could help advance conservation of bumblebees in agricultural landscapes in Sweden and improve our understanding of pollinators’ pathogen spread.
Preliminary data:
Several published works from collaborator J. de Miranda have shown the ubiquity of pathogens in honeybees and how these contribute significantly to honey bee colony losses. In addition, preliminary work from Laura Riggi, in agroecosystems in Sweden, suggests that mass flowering crops have beneficial impacts on bumblebee diversity, and honeybee abundances. This research project aims to build on previous research carried out by the applicants and link pathogen incidence in both managed and wild bees to landscape composition in arable landscapes in Sweden.
Relevance:
The pollination of flowering plants by insects represents a critical ecosystem service of great value to humanity, both monetary and otherwise. Pollination systems are under increasing threat from habitat fragmentation, modern agricultural practices, and invasions of non-native pathogens. The pollination crisis that is evident in declines of bees may be ameliorated by changes in habitat use and agricultural practices. Mass flowering crops have been suggested to benefit pollinators and offset their decline in agricultural landscapes. However, very little is known on how mass flowering crops cultivation will affect other drivers of pollinator declines, namely pathogen incidence. To sustainably restore pollinators biodiversity in Swedish agricultural landscapes there is a need to better understand how mass flowering crops will affect pollinators’ pathogens. We believe this is in line with the 2020 Oscar and Lili Lamm Memorial Foundation call on Landscape Conservation, which targets projects investigating preservation and restoration of biodiversity in Swedish landscapes. |