Drastic historic shifts in bumble-bee community composition in Sweden
Author
Summary, in English
The species richness of flower-visiting insects has declined in past decades, raising concerns that the ecosystem service they provide by pollinating crops and wild plants is threatened. The relative commonness of different species with shared ecological traits can play a pervasive role in determining ecosystem functioning, but information on changes in abundances of pollinators over time is lacking. We gathered data on relative abundances of bumble-bee species in Swedish red clover fields during three periods in the last 70 years (1940s, 1960s and present), and on clover seed yields since 1921. We found drastic decreases in bumble-bee community evenness, with potential consequences for level and stability of red clover seed yield. The relative abundances of two short-tongued bumble-bees have increased from 40 per cent in the 1940s to entirely dominate present communities with 89 per cent. Average seed yield declined in recent years and variation in yield doubled, suggesting that the current dependence on few species for pollination has been especially detrimental to stability in seed yield. Our results suggest a need to develop management schemes that promote not only species-rich but also more evenly composed communities of service-providing organisms.
Department/s
Publishing year
2012
Language
English
Pages
309-315
Publication/Series
Royal Society of London. Proceedings B. Biological Sciences
Volume
279
Issue
1727
Document type
Journal article
Publisher
Royal Society Publishing
Topic
- Ecology
- Earth and Related Environmental Sciences
Keywords
- Bombus spp.
- ecosystem service
- pollination
- Trifolium pratense
- red
- clover
Status
Published
Research group
- Biodiversity and Conservation Science
ISBN/ISSN/Other
- ISSN: 1471-2954