Title: Long-Term Global Trends in Crop Yield and Production Reveal No Current Pollination Shortage but Increasing Pollinator Dependency
Abstract: There is evidence that pollinators are declining as a result of local and global environmental degradation [1Biesmeijer J.C. Roberts S.P.M. Reemer M. Ohlemuller R. Edwards M. Peeters T. Schaffers A.P. Potts S.G. Kleukers R. Thomas C.D. et al.Parallel declines in pollinators and insect pollinated plants in Britain and the Netherlands.Science. 2006; 313: 351-354Crossref PubMed Scopus (1780) Google Scholar, 2Kluser S. Peduzzi P. Global Pollinator Decline: A Literature Review. UNEP/GRID, Geneva2007Google Scholar, 3Oldroyd B.P. What's killing American honey bees?.PLoS Biol. 2007; 5: e168Crossref PubMed Scopus (352) Google Scholar, 4National Research CouncilStatus of Pollinators in North America. National Academies Press, Washington, DC2007Google Scholar]. Because a sizable proportion of the human diet depends directly or indirectly on animal pollination [5Klein A.M. Vaissière B.E. Cane J.H. Steffan-Dewenter I. Cunningham S.A. Kremen C. Tscharntke T. Importance of pollinators in changing landscapes for world crops.Proc. R. Soc. B Biol. Sci. 2007; 274: 303-313Crossref PubMed Scopus (3003) Google Scholar], the issue of how decreases in pollinator stocks could affect global crop production is of paramount importance [6Allen-Wardell G. Bernhardt P. Bitner R. Burquez A. Buchmann S. Cane J. Cox P.A. Dalton V. Feinsinger P. Ingram M. et al.The potential consequences of pollinator declines on the conservation of biodiversity and stability of food crop yields.Conserv. Biol. 1998; 12: 8-17Crossref Scopus (573) Google Scholar, 7Kremen C. Ricketts T. Global perspectives on pollination disruptions.Conserv. Biol. 2000; 14: 1226-1228Crossref Scopus (118) Google Scholar, 8Steffan-Dewenter I. Potts S.G. Packer L. Pollinator diversity and crop pollination services are at risk.Trends Ecol. Evol. 2005; 20: 651-652Abstract Full Text Full Text PDF PubMed Scopus (245) Google Scholar]. Using the extensive FAO data set [9FAOSTAT. (2007). Data available at http://faostat.fao.org/site/408/default.aspx. Last accessed in January 2008.Google Scholar], we compared 45 year series (1961–2006) in yield, and total production and cultivated area of pollinator-dependent and nondependent crops [5Klein A.M. Vaissière B.E. Cane J.H. Steffan-Dewenter I. Cunningham S.A. Kremen C. Tscharntke T. Importance of pollinators in changing landscapes for world crops.Proc. R. Soc. B Biol. Sci. 2007; 274: 303-313Crossref PubMed Scopus (3003) Google Scholar]. We investigated temporal trends separately for the developed and developing world because differences in agricultural intensification, and socioeconomic and environmental conditions might affect yield and pollinators [10Matson P.A. Parton W.J. Power A.G. Swift M.J. Agricultural intensification and ecosystem properties.Science. 1997; 277: 504-509Crossref PubMed Scopus (1950) Google Scholar, 11Allen J.C. Barnes D.F. The causes of deforestation in developing countries.Annals of the Association of American Geographers. 1985; 75: 163-184Crossref Scopus (348) Google Scholar, 12Conway G. The doubly green revolution: Balancing food, poverty and environmental needs in the 21st century.in: Lee D.R. Barrett C.B. Tradeoffs or Synergies? Agricultural Intensification, Economic Development and the Environment. CABI Publishing, Wallinford2001: 17-34Crossref Google Scholar, 13Evenson R.E. Gollin D. Assessing the impact of the green revolution, 1960 to 2000.Science. 2003; 300: 758-762Crossref PubMed Scopus (1079) Google Scholar]. Since 1961, crop yield (Mt/ha) has increased consistently at average annual growth rates of ∼1.5%. Temporal trends were similar between pollinator-dependent and nondependent crops in both the developed and developing world, thus not supporting the view that pollinator shortages are affecting crop yield at the global scale. We further report, however, that agriculture has become more pollinator dependent because of a disproportionate increase in the area cultivated with pollinator-dependent crops. If the trend toward favoring cultivation of pollinator-dependent crops continues, the need for the service provided by declining pollinators will greatly increase in the near future.