Influences de l’organisation du paysage sur l’abondance des abeilles sauvages, leur diversité et le service de pollinisation en prairie permanente

Abstract : Wild bees (20 000 species worldwide) contribute to the pollination of 87.5% of angiosperm species. The decline of wild bees in Europe jeopardizes the sustainability of the pollination service. Among the causes of this decline, the diminution of the surface of semi-natural habitats (e.g. permanent grasslands), providing diverse floristic resources, plays an important role. While the surface of semi-natural habitats has reduced since the second half of the 20th century, the surface of oilseed rape has considerably increased in Europe. Oilseed rape offers a large amount of nectar and pollen during its flowering. The main objective of this study was to evaluate the influence of the spatial organization of semi-natural habitats and oilseed rape fields on the abundance of wild bees, their diversity and the pollination service in permanent grasslands. To achieve this objective, we implemented several experiments in permanent grasslands of the “Parc Naturel Régional de Lorraine”, during and after oilseed rape flowering. Firstly, we showed that the areas covered by flowering oilseed rape fields and semi-natural habitats influence the abundance and species richness of bees in permanent grasslands (different influences according to their sociality) as well as the body size intra-specific distribution of Andrena cineraria. Effects of oilseed rape disappear few weeks after oilseed rape flowering. Secondly, we found that the abundance in grasslands of Andrena cineraria (a species whose peak activity and larval feeding coincide with oilseed rape flowering period), during year N is positively related to the area covered by oilseed rape during the year N-1. Finally, a last experiment was conducted to detect potential effects of flowering oilseed rape on the pollination service in permanent grasslands. Our results showed that increasing areas of flowering oilseed rape in the landscape lead to a reduction of the reproductive success of Cardamine pratensis, a co-flowering wild plant in permanent grasslands. This study highlights the influence of oilseed rape on several trophic levels (pollinators and wild plants) and levels of organization of life (community and population) in permanent grasslands
Liste complète des métadonnées

Cited literature [83 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-01874584
Contributor : Abes Star <>
Submitted on : Friday, September 14, 2018 - 2:27:22 PM
Last modification on : Saturday, September 15, 2018 - 1:20:03 AM
Document(s) archivé(s) le : Saturday, December 15, 2018 - 2:32:27 PM

File

DDOC_T_2017_0311_VAN_REETH.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01874584, version 1

Collections

Citation

Colin Van Reeth. Influences de l’organisation du paysage sur l’abondance des abeilles sauvages, leur diversité et le service de pollinisation en prairie permanente. Ecologie, Environnement. Université de Lorraine, 2017. Français. ⟨NNT : 2017LORR0311⟩. ⟨tel-01874584⟩

Share

Metrics

Record views

147

Files downloads

185