We get hours of amusement from poking holes in the many ways in which statements about the loss of 75% of agricultural biodiversity are likely to be less than accurate any way you slice them. But here’s an entirely new wrinkle. A friend recently wrote asking for some moral support for a grant proposal, which included a forceful justificatory phrase to the effect that 75% of agricultural diversity has been lost since 1990. ((My emphasis, as the posh editors say.))
I twitted him gently about this, something snitty to the effect of “interesting statistic, have you got a source for that?” And blow me down if he didn’t. Not just any old source either. A communication from the [European] Commission to the European Parliament, the Council, the Economic and Social Committee and the Committee of the Regions, no less, entitled Our life insurance, our natural capital: an EU biodiversity strategy to 2020, aka COM(2011) 244 final.
And there it is, on page 1 of the Introduction.
[A]ccording to the FAO … 75% of the genetic diversity of agricultural crops has been lost worldwide since 1990.
I wonder where they got that figure? Not from FAO. The same year is present in at least one other language, so if it is a typo it entered the proceedings early. But honestly, did nobody find it just the least little bit odd? Then again, my friend didn’t either. I suppose we’re the odd ones.
Here’s one study that did have data, and didn’t detect a significant loss: Ford-Lloyd, B.V., D. Brar, G.S. Khush, M.T. Jackson & P.S. Virk, 2008. Genetic erosion over time of rice landrace agrobiodiversity. Plant Genetic Resources: Characterization and Utilization 7(2), 163-168.
How many studies are there that really compare two samples taken at different moments in time?
This is my list (apart from the study mentioned by Mike above), but I am sure there are more studies.
Sperling, L. (2001) The effect of the civil war on Rwanda’s bean seed systems and unusual bean diversity. Biodiversity and Conservation 10(6), 989-1010.
Jacob van Etten. 2006. Changes in farmers’ knowledge of maize diversity in highland Guatemala, 1927/37-2004. J Ethnobiol Ethnomed. 2006; 2: 12.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1440848/
Routson, Kanin J., Reilley, Ann A., Henk, Adam D., Volk, Gayle M. (2009). Identification of historic apple trees in the Southwestern United States and implications for conservation. HortScience 2009 44: 589-594.
Bezançon, G. et al. 2009. Changes in the diversity and geographic distribution of cultivated millet (Pennisetum glaucum (L.) R. Br.) and sorghum (Sorghum bicolor (L.) Moench) varieties in Niger between 1976 and 2003. Genetic Resources and Crop Evolution 56(2), 223-236.
Deu M, et al. (2010) Spatio-temporal dynamics of genetic
diversity in Sorghum bicolor in Niger. Theor Appl Genet. 120:1301–1313. http://www.ncbi.nlm.nih.gov/pubmed/20062963
de Haan, S. et al. (2010) Multilevel Agrobiodiversity and Conservation of Andean Potatoes in Central Peru. Mountain Research and Development 2010 30 (3), 222-231.
“Few of the 850 varieties of pear, for example, that were listed by T. W. Field in 1858, could now, I suppose, be found anywhere in the world. It is the fate of varieties to come and go.” (Fairchild, 1938).
Fairchild, D. 1938 Reminiscences of early plant introduction work in South Florida. Proceedings of the Florida State Horticultural Society 51, 11-33.
Field T.W. 1858 Pear Culture: A Manual for the Propagation, Planting, Cultivation, and Management of the Pear Tree. Orange Judd & Co., New York
Fairchild, who knew what he was talking about, is telling us: “It could be 75%, but so what?” And I always ask about the loss of those thousands of apple varieties in the US: “How many did they have in 1492?”