@article{KlattHolzschuhWestphaletal.2014,
  author    = {Klatt, Bj{\"o}rn K. and Holzschuh, Andrea and Westphal, Catrin and Clough, Yann and Smit, Inga and Pawelzik, Elke and Tscharntke, Teja},
  title     = {Bee pollination improves crop quality, shelf life and commercial value},
  series = {Proceedings of the Royal Society B: Biological Sciences},
  volume    = {281},
  journal   = {Proceedings of the Royal Society B: Biological Sciences},
  number    = {1775},
  doi       = {10.1098/rspb.2013.2440},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120797},
  year      = {2014},
  abstract  = {Pollination improves the yield of most crop species and contributes to one-third of global crop production, but comprehensive benefits including crop quality are still unknown. Hence, pollination is underestimated by international policies, which is particularly alarming in times of agricultural intensification and diminishing pollination services. In this study, exclusion experiments with strawberries showed bee pollination to improve fruit quality, quantity and market value compared with wind and self-pollination. Bee-pollinated fruits were heavier, had less malformations and reached higher commercial grades. They had increased redness and reduced sugar-acid-ratios and were firmer, thus improving the commercially important shelf life. Longer shelf life reduced fruit loss by at least 11\%. This is accounting for 0.32 billion US\$ of the 1.44 billion US\$ provided by bee pollination to the total value of 2.90 billion US\$ made with strawberry selling in the European Union 2009. The fruit quality and yield effects are driven by the pollination-mediated production of hormonal growth regulators, which occur in several pollination-dependent crops. Thus, our comprehensive findings should be transferable to a wide range of crops and demonstrate bee pollination to be a hitherto underestimated but vital and economically important determinant of fruit quality.},
  language  = {en}
}
@article{BreezeVaissiereBommarcoetal.2014,
  author    = {Breeze, Tom D. and Vaissiere, Bernhard E. and Bommarco, Riccardo and Petanidou, Theodora and Seraphides, Nicos and Kozak, Lajos and Scheper, Jeroen and Biesmeijer, Jacobus C. and Kleijn, David and Gyldenk{\ae}rne, Steen and Moretti, Marco and Holzschuh, Andrea and Steffan-Dewenter, Ingolf and Stout, Jane C. and P{\"a}rtel, Meelis and Zobel, Martin and Potts, Simon G.},
  title     = {Agricultural Policies Exacerbate Honeybee Pollination Service Supply-Demand Mismatches Across Europe},
  series = {PLOS ONE},
  volume    = {9},
  journal   = {PLOS ONE},
  number    = {1},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0082996},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117692},
  pages     = {e82996},
  year      = {2014},
  abstract  = {Declines in insect pollinators across Europe have raised concerns about the supply of pollination services to agriculture. Simultaneously, EU agricultural and biofuel policies have encouraged substantial growth in the cultivated area of insect pollinated crops across the continent. Using data from 41 European countries, this study demonstrates that the recommended number of honeybees required to provide crop pollination across Europe has risen 4.9 times as fast as honeybee stocks between 2005 and 2010. Consequently, honeybee stocks were insufficient to supply >90\% of demands in 22 countries studied. These findings raise concerns about the capacity of many countries to cope with major losses of wild pollinators and highlight numerous critical gaps in current understanding of pollination service supplies and demands, pointing to a pressing need for further research into this issue.},
  language  = {en}
}
@article{HopfenmuellerSteffanDewenterHolzschuh2014,
  author    = {Hopfenmueller, Sebastian and Steffan-Dewenter, Ingolf and Holzschuh, Andrea},
  title     = {Trait-Specific Responses of Wild Bee Communities to Landscape Composition, Configuration and Local Factors},
  doi       = {10.1371/journal.pone.0104439},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112872},
  year      = {2014},
  abstract  = {Land-use intensification and loss of semi-natural habitats have induced a severe decline of bee diversity in agricultural landscapes. Semi-natural habitats like calcareous grasslands are among the most important bee habitats in central Europe, but they are threatened by decreasing habitat area and quality, and by homogenization of the surrounding landscape affecting both landscape composition and configuration. In this study we tested the importance of habitat area, quality and connectivity as well as landscape composition and configuration on wild bees in calcareous grasslands. We made detailed trait-specific analyses as bees with different traits might differ in their response to the tested factors. Species richness and abundance of wild bees were surveyed on 23 calcareous grassland patches in Southern Germany with independent gradients in local and landscape factors. Total wild bee richness was positively affected by complex landscape configuration, large habitat area and high habitat quality (i.e. steep slopes). Cuckoo bee richness was positively affected by complex landscape configuration and large habitat area whereas habitat specialists were only affected by the local factors habitat area and habitat quality. Small social generalists were positively influenced by habitat area whereas large social generalists (bumblebees) were positively affected by landscape composition (high percentage of semi-natural habitats). Our results emphasize a strong dependence of habitat specialists on local habitat characteristics, whereas cuckoo bees and bumblebees are more likely affected by the surrounding landscape. We conclude that a combination of large high-quality patches and heterogeneous landscapes maintains high bee species richness and communities with diverse trait composition. Such diverse communities might stabilize pollination services provided to crops and wild plants on local and landscape scales.},
  language  = {en}
}