Interactions plantes-pollinisateurs et reproduction de Comarum palustre L. (Rosacées)
(2013)
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- Authors
- Supervisors
- Jacquemart , Anne-Laure
- Abstract
- Peat bogs and fens have been tremendously destroyed and fragmented in Belgium. Subsequently, several plant species are threatened due to their restriction to these habitats. The goal of this PhD thesis is to determine the reproductive biology and conservation status of populations of the marsh cinquefoil Comarum palustre L. (Rosaceae). Therefore, the abundance of its main pollinators and their floral resource use were studied, as well as the reproductive success and population genetics of the target plant species. Bumble bees and solitary bees are the major pollinators of C. palustre. Their abundance is positively correlated to woody areas, forest edges and within population flower density, as the present study describs its floral resources (pollen and nectar) as highly attractive to bumble bees. The present study further highlights the role of floral resource quality on bumble bee floral choices. Comarum palustre shows signs of pollen limitation. Its reproductive success depends on the visitation rate of its major pollinators due to its protandry. No effect of habitat fragmentation on population genetic diversity was highlighted. However, continuous plant populations showed higher realized outcrossing rates than patchy populations (0.83-0.84 vs. 0.33-0.46). The outcrossing rate was also related to the genet size. Pollen dispersal mainly occurred within patches as only 1–7 % of the pollination events occurred between patches of >25 m separation. The occurrence of inbreeding depression was not detected at the seed set stage (δ = 0.04). The results of this PhD thesis suggest that landscape heterogeneity and structure influence pollinator abundance and behaviour, which in turn affect the reproductive success and the mating system of C. palustre. This study will have implications in terms of management and conservation strategies, such as the setting and the improvement of management practices within peat bogs and fens.
- Affiliations
Citations
Somme, L. (2013). Interactions plantes-pollinisateurs et reproduction de Comarum palustre L. (Rosacées). https://hdl.handle.net/2078.5/47584