GIS – Page 48 – Agricultural Biodiversity Weblog

May 2, 2017May 2, 2017

More Mexican maize mayhem

It didn’t take long for my prediction to come true that the Mexican maize dataset I blogged about a couple of weeks back would get some more attention. The lead author of that previous paper, Hugo Perales, has teamed up with Quetzalcóatl Orozco-Ramírez and our old friend Robert Hijmans to do a deep dive into the database of 18,176 georeferenced observations of about 60 maize races. Some key findings:

Both at national and state level, there are a few very common races, and many races with very few observations.
10% of the races account for 54% of the records.
Over half of the races account for 10% of the records.
The maximum distance between two records of the same race was just over 1000 km on average, the maximum about 2600 km, and lower than 200 km for 7 races.
There was a positive association between the number of observations and the number of races in both 50 km and 100 km square cell.

I particularly liked the new map of “maize communities,” that is, regions where more or less similar assemblages of races are found.

Although the previous paper had a similar map of “biogeographic regions,” this is more detailed and robust. Intriguingly, the hotspots of highest diversity tend to occur where distinct maize communities meet.

I’ll see if I can get Robert so say a few words about this work here.

April 26, 2017March 5, 2026

Nibbles: Investing in food, Henna botany, Buckwheat promotion, Mapping India, Optimism, Genetic diversity, Forest cocktails

Psst, you have any examples of investments for healthy food systems? What do you mean, you don’t.
Paint it henna.
Pleading for pseudocereals. In Switzerland?
Mapping India’s trees. Among other things.
To save biodiversity, look on the bright side. Easy for you to say.
The genetic level of biodiversity makes important contribution to ecosystem services. In birds. Right.
Taste the forest. In cocktails.

April 24, 2017April 10, 2017

Brainfood: Tomato chemicals, Photoperiod, Grain phenotyping, Hawaiian ag, Domestication primer, Symbionts, Turkish wheat, Yam bean diversity, Crop health, Walnut diversity, Agrobiodiversity theorising, Sea pigs, NERICA impacts, Nutrient production

Multi-perspective evaluation of phytonutrients – Case study on tomato landraces for fresh consumption. Fancy maths proves different tomato varieties taste different.
Adaptation to the Local Environment by Modifications of the Photoperiod Response in Crops. It’s all down to a few mutations in all crops.
Evaluation of the SeedCounter, A Mobile Application for Grain Phenotyping. Seems like a lot of work to just be able to measure wheat seeds, but boys will have their toys.
Indigenous Polynesian Agriculture in Hawaiʻi. Both intensive and extensive.
How to make a domesticate. It takes a long time, and involves lots of genes.
Symbiosis limits establishment of legumes outside their native range at a global scale. Non-symbiotic legumes have spread further than symbiotic ones into non-native areas.
Wheat Landraces Currently Grown in Turkey: Distribution, Diversity, and Use. More than half of morphotypes (59%) lost since 1920 overall, but none in some areas.
Ecotypic differentiation under farmers’ selection: Molecular insights into the domestication of Pachyrhizus Rich. ex DC. (Fabaceae) in the Peruvian Andes. Separate Amazonian and Andean lineages, and P. tuberosum arising from P. ahipa.
Crop health and its global impacts on the components of food security. To better understand acute impacts, model systemic ones.
Climate-Related Local Extinctions Are Already Widespread among Plant and Animal Species. About half of about 1000 species showed local extinction.
Rethinking the history of common walnut (Juglans regia L.) in Europe: Its origins and human interactions. Expansion from glacial refugia, followed by human exploitation. Compare and contrast with Asia. Or read about the whole thing in AramcoWorld.
Agrobiodiversity and a sustainable food future. Apparently all you need to do to support the “use of biological diversity in sustainable agricultural and food systems” is to recognize that there are 4 interconnected themes: (1) genetic resources, ecology and evolution; (2) governance policy, institutions and legal agreements; (3) food, nutrition, health and disease; and (4) global change drivers with social ecological interactions.
Eastern Mediterranean Mobility in the Bronze and Early Iron Ages: Inferences from Ancient DNA of Pigs and Cattle. Anatolia to southeastern Europe and back to the Levant across the Bronze-Iron Age transition. The Sea Peoples had pigs?
Contribution of improved rice varieties to poverty reduction and food security in sub-Saharan Africa. NERICA adoption increased annual per capita income by US$4 per year from 2000, despite yields going down a bit.
Farming and the geography of nutrient production for human use: a transdisciplinary analysis. Need to try to maintain production diversity as farm size increases. But let Jess Fanzo explain it better.

April 12, 2017February 16, 2018

Mapping wheat diversity in Turkey

No sooner did I blog about a paper which mapped diversity in a crop in Mexico across time, that I came across one mapping diversity in another crop in Turkey. ¹

The authors — a truly international bunch from the Bahri Dagdas International Agricultural Research Institute, the Vavilov Institute, CIMMYT, ICARDA, FAO, and UC Davis — describe a huge effort to collect and describe wheat from all over the country during 2009-2014. They then compare the resulting socioeconomic and geographic patterns of diversity with a previous survey done by the Vavilov Institute in the 1920s, the results of which were published in 1935-9 by Mirza Gökgöl, a Turkish scientist who accompanied that expedition. ²

As in the Mexican maize study, diversity in the crop was measured in terms of distinct morphological types, and was unevenly distributed around the country, but unlike in that work, diversity was calculated for each administrative province, rather than in each square in a grid. As provinces vary widely in size, and in the extent to which wheat is grown in them, this approach is not ideal.

Nevertheless, it was possible to make direct comparisons between the two study periods for about 17 provinces. Discounting some very rare and very minor morphological variants, it seems fairly safe to say that for these provinces, the number of distinct wheat types went down about 59% overall, though with large differences among provinces. There is no map showing this in the paper, but, thanks to my colleague Nora Castañeda, I can help you with that. Red is down, green is up.

Data from Morgounov et al. (2016) Table 4. Wheat landrace diversity for selected provinces in Turkey found in the 1920s compared with the current results (2000s).

What explains wheat landraces still thriving in some places, and not in others?

Socioeconomic data indicated that landrace farmers are found mostly in remote mountainous subsistence communities with very little grain trade, small areas planted to wheat, and relatively simple production technologies. The key reasons famers continue to grow landraces are their grain qualities and adaptation to abiotic stresses.

April 6, 2017March 5, 2026

Mapping the hell out of maize diversity in Mexico

Thanks to a Facebook post, I’ve just come across the “mapoteca digital” of CONABIO, the Comisión Nacional para el Conocimiento y Uso de la Biodiversidad of Mexico. ³ It has point maps of the distribution of both wild and cultivated beans and calabazas, and of wild maize; but most interesting to me were the maps of the distribution of the richness of cultivated maize races, based on collections made at different times in the past. The data were put together by the “Proyecto Global de Maíces” (2006-2010), and the maps are also available in a PDF.

Here’s the map for 1940-1965, based on about 3,000 collections.

And here’s the map for 1991-2000, based on 12,000 collections.

The legend used in both maps is at the left here. Looking at the maps, lots of questions came to mind. Why are we getting higher numbers of races in the 1990’s? Is it that the collecting was more thorough then? Or are races moving around more now? There is lots of information on the individual races on the project website, including actual and potential distribution maps. And you can download the raw data. So another thing that came to mind was that surely someone must have gone through all this stuff in detail. And sure enough, yes someone had indeed gone through all this stuff in detail, Peralta & Golicher in 2014. ⁴

The high rank correlation between the three collection efforts indicate that relative abundance of races has not changed considerably since 1950. Races that were common in 1950 were also common in 2005, and the same can be said for rare races, none of these were apparently more common in 1950. Correspondingly, the comparison of distribution and richness models for the three sampling efforts does not suggest a general decline in richness nor in distribution for 43 of the 47 races studied, and in the other four cases the declines are relatively minor and require verification. The recent increase in distribution for two races (Tuxpeño and Celaya) may be explained by the outstanding importance these have had as components in commercial cultivars, it is not uncommon to find recycled and creolized landraces that had their origin as commercial seeds. Also, no extinctions were reported for the 47 races studied since all were sampled in the last collection effort between 1997 and 2010. Therefore, in a broad sense, at the race level of classification we do not find signs of substantial genetic erosion between 1943 and 2010. That is not to say no losses of local populations have occurred.

I can’t for the life of me understand why I haven’t blogged about this paper before (or indeed the project that generated the data), bringing together as it does two of my very favourite things, agrobiodiversity and mapping ⁵, but I’m more than happy to rectify that oversight here and now. I can’t help thinking there’s more to be mined from this dataset yet.