There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops. Dominant crop pollinators persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments.
Bibliographical noteFunding Information:
This research was funded by Agence Nationale de la Recherche Programme OGM, project ANR-06-POGM-004 GMBioImpact; EC FP6 ALARM-Project (GOCE-CT-2003- 506675 (www.alarmproject.net/alarm/); LEGATO-Project (German Federal Ministry of Education and Research; DLR 01LL0917D); Biotechnology and Biological Sciences Research Council, Defra, Natural Environment Research Council, the Scottish Government and the Welcome Trust, under the Insect Pollinators Initiative (http://wiki.ceh.ac.uk/display/ukipi/Home); Army Research Organization; Deutsche Bundesstiftung Umwelt, German Research Foundation (DFG BA 4438/1-1); EC FP5 project EASY (QLRT 2001 01495); EC FP7 project STEP (244090; www.STEP-project.net), EC FP7 project LIBERATION (311781; www.fp7liberation.eu); EC FP7 project SCALES (www.scales-project.net), Dutch Ministry of Economic Affairs (BO-11-011.01-011); French Ministry of Agriculture (CASDAR programme no. 9035); ANRT CIFRE PhD grant GEF/UNEP/FAO Global Pollination Project (http://www. internationalpollinatorsinitiative.org/jsp/globalpollproject.jsp); MBIE Bee Minus to Bee Plus C11X1309; Foundation for Arable Research; MTA Lendület programme, Hungarian Scientific Research Fund (OTKA NN 101940); Natural Sciences and Engineering Research Council of Canada (NSERC-CANPOLIN); BC Blueberry Council, NSF GRFP, NIFA (National Institute for Food and Agriculture, USDA), Western SARE (Sustainable Agriculture Research and Education), NSF-DBI no. 0956388; Robert G. Goelet, Smith Lever and Hatch Funds administered by Cornell University Agricultural Experiment Station, USDA-AFRI (USDA 2010-03689); the Swedish Research Council Formas; The Israel Ministry of Agriculture, Research grant no. 824-0112-08, The Israel Science Foundation Research grant no. 919/09; The Ministry for Science and Culture of Lower Saxony grant no. 11-76-251-99-06/08, PROBIO/MMA, PIBIC-CNPq; USDA (NIFA-AFRI 2009-65104-05782); New Jersey Agricultural Experiment Station (Hatch Multistate Project no. 08204), USDA AFRI 2009-02305, USDA Natural Resource Conservation Service (Conservation Innovation Grant 69-3A75-10-163); Virginia Cooperative Extension and Virginia Tech Graduate Student Assembly.