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Drastic historic shifts in bumble-bee community composition in Sweden

  • Riccardo Bommarco
  • Ola Lundin
  • Henrik Smith
  • Maj Rundlof
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

Abstract 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.


  • Ecology
  • Earth and Related Environmental Sciences
  • Bombus spp.
  • ecosystem service
  • pollination
  • Trifolium pratense
  • red
  • clover


  • BECC
  • ISSN: 1471-2954
Henrik Smith
E-mail: henrik [dot] smith [at] biol [dot] lu [dot] se



+46 46 222 93 79

+46 70 978 20 56




Centre for Environmental and Climate Research (CEC)

+46 46 222 93 79

+46 70 978 20 56


Sölvegatan 37, Lund


Centre for Animal Movement Research
Evolutionary Ecology, Department of Biology
Ecology building S-223 62 Lund Sweden