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Taller semillas 2011 Mauricio Bellon

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  • 1. How Local is Local?Assessing the Vulnerability of TraditionalMaize Seed Systems in Mexico to Climate Change Mauricio R. Bellon1, David Hodson2 and Jon Hellin2 1Bioversity International, 2CIMMYT
  • 2. Maize and traditional seed systems Maize continues to be a fundamental crop for millions of small-scale farmers in Mexico The vast majority rely on themselves or fellow farmers to obtain seed to plant every season Sourcing of seed is not a random event but is embedded in a well-structured system with rules and expectations Traditional seed systems are based on family and local social networks, regulated by ideas of fairness, and of respect to the seed
  • 3. Climate change and traditional seedsystems Climate change is predicted to have major impacts on small scale farmers in the developing world but these impact are likely be complex, locally-specific and hard to predict (Morton 2007) Mexico and Central America are predicted to be a region at considerable risk from climate change Given the importance of maize cultivation for the wellbeing of small scale farmers and of the seed systems that underpin it, it is fundamental to explore the potential impacts of climate change on traditional seed systems
  • 4. Hypothesis and assumptions The hypothesis addressed here is that traditional maize seed systems may not be able to provide small-scale farmers with adapted landraces in the face of climate change  because they are “too local” relative to the spatial scope of environmental shifts expected with climate change It is assumed that if predicted environments are similar to current ones, the scope of the seed systems is adequate if not, farmers may need to get seed outside their traditional ranges, in areas resembling the novel environment they will face
  • 5. Methods The spatial scope of traditional maize seed systems was studied in transects across an altitudinal gradient from 10 to 2980 masl in five states of eastern Mexico (Veracruz, Puebla, Tlaxcala, Hidalgo, Edo. de Mexico) A random sample of 20 communities in four transects were selected, with 20 households per community randomly chosen for a total sample of 400 households (survey carried out in 2003) An inventory of seed lots used by household was elicited with the specific location where the seed was obtained and then mapped The spatial scope of the origin of seed lots was linked to maize agro-climate environments as defined by CIMMYT (Setimela et al. 2005) Three major IPCC global circulation models were used, downscaled to cover the study region for 2050 To address some of the uncertainties from GCM’s and emission scenarios, median values for the six alternative future climates in 2050 (3 GCM x 2 scenarios) were used to represent a likely future scenario and one extreme one HadCM3, scenario A2 for 2050 Potential environmental shifts in agro-climate environments were compared to the current spatial scope of traditional seed systems
  • 6. Transects 10 – 2980 masl in Eastern Mexico• 20 communities Marginality level Communities• 20 households/ community (poverty) 2005• 4 maize agro-climatic zones: wet lowland, High 16 dry lowland, Medium 3 wet upper mid-altitude Low 1 highland Source: CONAPO
  • 7. Farmers’ characteristicsMaize agro-climatic zone WL DL WUMA H Total Signif.Indigenous households (%) 64.3 15.0 50.0 3.3 30.5 0.0000Mean number of crops 2.8 2.3 2.8 3.9 3.2 0.0000Mean number of fruit tree species 1.3 1.8 1.7 0.6 1.1 0.0000Mean number of domestic animal species kept 1.9 1.1 2.2 2.8 2.3 0.0000Households who perform off-farm labor 56.4 47.5 72.5 41.1 50.3 0.001Mean number of non farm activities/hh 2.5 2.6 2.7 2.4 2.5 nsMaize planted Spring-Summer (mean area/hh) 1.8 1.9 1.3 3.0 2.3 0.0004 Autumn-Winter (mean area/hh) 1.8 1.9 1.1 0.0 1.7 nsType of maize producers (%) deficit 27.1 32.5 52.5 36.1 34.3 0.08 equilibrium 12.9 7.5 12.5 11.7 11.7 surplus 60 60 35 52.2 54Number of uses of maize 3.3 3.2 2.7 3.2 3.2 nsFarmers who produce for self consumption 99.29 97.5 95 97.21 97.74 nsFarmers who sell 60 42.5 50 42.2 49.3 0.013Household with migrants within country 22.86 22.5 25 17.8 20.8 nsHousehold with migrants outside country 5.7 17.5 10 17.8 12.75 0.006 WL: Wet Lowland; DL: Dry Lowland; WUMA: Wet Upper Mid-altitude; H: Highland
  • 8. Characterizing traditional seed systems Wet Upper Wet Dry Mid-Maize mega-environment Lowland Lowland altitude Highland Total Signif.No. of seed lots (SL) 177 47 62 318 604SL of landraces (%) 98.3 97.9 98.4 97.5 97.9 nsAverage no SL/farmer 1.3 1.2 1.6 1.8 1.5 0.000SL size 20.0 14.0 9.0 20.0 18.0 0.000SL saved by farmer (%, 2003) 75.7 85.1 82.3 72.6 75.5 nsIf not saved, obtained from family, friends,neighbors (%) 88.1 85.7 100.0 85.1 87.0 nsAge of SL saved by farmer (median, years) 10.0 10.0 15.0 8.0 10.0 0.02SL obtained outside community historical (%) 13.0 12.8 4.8 28.6 20.4 0.000SL obtained outside community 2003 (%) 1.7 0 0 6.6 3.7 0.001SL provided to other farmers 2002 (%) 25.4 23.4 29.0 18.2 21.9 nsSL provided outside the community 2002 (%) 1.7 4.3 0 3.8 2.8 ns
  • 9. Spatial reach of seed systems studycommunities
  • 10. Farmer experimentation Wet Upper Wet Dry Mid-Maize agro-climatic zone Lowland Lowland altitude Highland Total Signif.Farmers who experimented (%) 19.3 22.5 12.5 34.1 25.6 0.003Number of experimental SL 30 13 5 79 127Experimental SL of improved varieties 10 4 1 4 19Experimental SL retained 6 1 0 9 16SL of improved varieties retained 2 1 0 0 3 •Farmers experiment with landraces and improved varieties •Retention is low, particularly of improved varieties •Improved varieties found wanting
  • 11. The spatial scope of traditional seed systems Wet Upper Wet Dry Mid-Maize agro-climatic zone (%) Lowland Lowland altitude Highland Total Signif.SL obtained < 10 km historical 96.0 93.5 100 87.1 91.6 0.000SL obtained < 10 km 2003 99.4 100 100 97.2 98.3 0.054SL obtained altitude +/- 50 m historical 96.5 95.7 95.2 78.8 87.0 0.000SL obtained altitude +/- 50 m 2003 99.4 100 100 95.2 97.3 0.01SL distributed < 10 km 2002 97.6 100 100 100 99.2 nsSL distributed to altitude +/- 50 m 2002 100 100 100 90.2 95.8 0.033 • more than 90% of seed lots originated and were distributed within a radius of less than 10 km of where they were planted • though with statistically significant differences across environments
  • 12. Histogram of the distances from which seed lotswere acquired historically differentiated by maizeagro-climate environment
  • 13. Predicted changes in maize agro-climate environments current-2050current Median of 6 futures HadCM3 model A2a scenario
  • 14. Changes in the spatial scope of current traditional seed systems under predictions of climate change % of pixels covered by a Number of studied 10 km radius communities Future climateMaize mega- already withinenvironment Current 2050 Change Total the 10 KmWet Lowland 33.7 31.6 -2.1 7 7Dry Lowland 12.0 18.3 2.7 2 2Wet Lower Mid-altitude 4.4 2.7 -1.7Wet Upper Mid-altitude 5.1 4.7 -0.4 2 2Dry Mid-altitude 0.9 8.5 7.6Highland 32.8 24.8 -8.0 8 6
  • 15. Results Traditional seed systems are quite local 90% of the seed lots are obtained within 10 km of the community Most seed lots are saved and of landraces Seed not saved is mostly obtained from family, friends and neighbors (local social networks) Highland agro-climate environment is the most open and dynamic in terms of seed flows Significant changes in maize agro-climate environments with climate change are expected  Most dramatic in the highlands that almost disappears
  • 16. Results (con’t) Except in the highland mega environment, all studied communities already have access to predicted mega environments within a 10 km radius Traditional seed systems may be able to cope with predicted climate change, except in the highland mega environment Preliminary research indicates that highland landraces do not appear to express the plasticity necessary to sustain productivity under climate change (Mercer and Perales, 2010) Highland mega environment merits particular attention in terms of adaptation measures to climate change for maize farmers This may require increasing the spatial scope of the highland seed systems and connecting farmers to others outside their traditional range
  • 17. Conclusions Traditional seed systems in study area have a limited spatial scope—are quite local However, results indicate that they should be able to continue to provide adapted landraces under predicted climate change, except in the highlands These results apply to the study area, and may be different for other parts of the country and for other crops There is a need for further research on the spatial scope of traditional seed systems and on the evolutionary capacity of landrace populations to climate change
  • 18. Global relevance: the issue and theapproach Results presented here quite local, but Traditional seed systems important for millions of small-scale farmers worldwide and will be affected by climate change, hence the issue is of global relevance Approached that can be replicated under diverse conditions:  Quantifying the spatial scope of the systems  Relating this scope to potential climate shifts that would modify the distribution of growing environments and hence the fit between the current germplasm used and the future needed