Thanks to Kai Sonder for this beautiful video of cowpea cultivation around the world.
Here’s genebank accessions in Genesys for comparison.
How diverse can croplands be?
A guest post from Fernando Aramburu Merlos on his recent paper with friend-of-the-blog Robert Hijmans.
Four species (wheat, rice, maize, and soybean) occupy half the world’s croplands. It has been argued that this means we cannot increase crop species diversity much without changing what we eat ((Renard, D. & Tilman, D. Cultivate biodiversity to harvest food security and sustainability. Curr. Biol. 31, R1154–R1158 (2021) )). Radically shifting our diets is a tall order, not just because changing habits is a challenge but also because we are so good at growing and processing the major crops. It’s an unfair race in which the major crops have a head start of millions of dollars and research hours.
We wanted to know how much crop diversity can be increased without changing the global food supply ((Aramburu Merlos, F. & Hijmans, R. J. Potential, attainable, and current levels of global crop diversity. Environ. Res. Lett. 17, 044071 (2022) )). So we estimated the attainable crop diversity, which is the highest level of crop species diversity you can get without changing the total production of each crop. To compute this, we “shuffled the cards and dealt again”: over 100 crops were distributed across the worlds’ existing croplands by allocating each to the most suitable land while considering the inter-specific competition for land.
It turned out that tropical and coastal regions can reach much higher levels of diversity than temperate and continental areas. Perhaps that is not especially surprising, but one implication is that we should not assume that all countries can achieve the same maximum levels of crop diversity ((This assumption was made for the agrobiodiversity index proposed by Jones, S. K. et al. Nat. Food 2, 712–723 (2021))). We also noted that attainable diversity cannot explain current diversity patterns very well. For example, the diversity gap, the difference between the current and the attainable diversity, is much higher in the Americas than in Europe and East Asia.
Diversity gaps, expressed as a percentage of the attainable diversity, are greater than 50% in 85% of the world’s croplands. Thus, in principle, crop diversity could double in the vast majority of the world without changing our heavy reliance on a few staple crops. So there must be strong forces at work that make farmers and regions specialize. For example, at the farm level, a high crop diversity may be difficult to manage, reduce economies of scale, and be costly if it comes at the expense of the most profitable crops.
It would be interesting to better understand what specific factors limit diversification in the regions with the largest crop diversity gaps, and how to reduce them. But more important questions need to be answered first. How much diversity is enough diversity? And is that the same for all regions? Some very low diversity systems appear to be highly sustainable (the flooded rice systems in Asia come to mind). A more spatially explicit and species-specific, functional understanding of the effect of diversity at the field scale would be helpful. Without that, diversity gaps are just an interesting emergent property of specialization, but not something that necessarily must be reduced.
The limits of protected areas
There’s an interesting paper just out in Nature entitled “Protected areas have a mixed impact on waterbirds, but management helps.” It’s unfortunately behind a paywall, but one of the authors, Dr Julia Jones, has done a helpful Twitter thread about it, which I’ve unspooled here if you dislike social media. There’s also mainstream media coverage, of course.
Do protected areas effectively conserve species populations? Our paper out today in @Nature tries to answer this really important question.https://t.co/XFzLS5Iqmr
— Julia Jones (@juliapgjones) April 20, 2022
The authors analysed data on waterbird populations before and after protection of sites, mainly in North America and Europe, as collected by thousands of volunteers. They found a mixed and confusing picture, with designation of a protected area having a wide range of impacts from negative to positive on the population sizes of the birds found therein.
Disappointing, I know, but there was a ray of light. As the title of the paper says, management made a difference. If the protected area was specifically managed with waterbirds in mind, then the impact of protection was more likely to be positive.
Which is why some of us who are interested in the conservation of things other than birds think there should be a global network of protected sites for crop wild relatives (CWR). In the same way that we just can’t rely on the generalised protection afforded by legal designation of a national park, or whatever, to do anything for waterbirds, we can’t expect it a priori to do anything for CWR either.
But does that mean that we’ll need millions of protected areas around the world, each specialising only in this or that species or group of species? I don’t think so. What we do need is for the CWR conservation community to work closely with the managers of existing protected areas to make sure that the correct interventions are applied to make sure that the CWR populations which happen to occur within their borders are able to thrive. That would probably not be enough, and it may well be necessary to set up some additional protected areas specifically devoted to CWR. But it would be a good start. And we do have a good a good evidence base. ((There’s also this interactive portal covering Europe.))
Incidentally, some of authors of the waterbirds paper have another paper out, “Language barriers in global bird conservation,” which is also well worth reading. About 15% of the more than 10,000 birds they looked at have geographic distributions within which more than 10 languages are spoken. And even when you control for area, threatened birds have significantly more languages spoken within their distributions. Which clearly is a challenge for conservation. I wonder if there’s something similar happening with CWR.
Brainfood: Digitizing collections, Bean core, Livestock diversity, Maya & maize, Fish stocks & CC, Save the weed, Flax CWR, Italian agrobiodiversity
- Cross-validation of a semantic segmentation network for natural history collection specimens. Computers can distinguish the herbarium label from the actual specimen and other stuff on the sheet, helping with the whole automatic digitization thing, but it takes some really fancy math.
- The landscapes of livestock diversity: grazing local breeds as a proxy for domesticated species adaptation to the environment. Medium fancy math used to map breed diversity in the Iberian Peninsula for different livestock species and relate it to environmental factors.
- South-to-north migration preceded the advent of intensive farming in the Maya region. Sort of like tomato, but in the other direction. Plenty of math involved, but behind the scenes, thankfully.
- Timing and magnitude of climate-driven range shifts in transboundary fish stocks challenge their management. Huge amount of data and very fancy math shows fish are in trouble.
- A Core Set of Snap Bean Genotypes Established by Phenotyping a Large Panel Collected in Europe. Ok, even I can follow the math on this one.
- Assessment of biogeographic variation in traits of Lewis flax (Linum lewisii) for use in restoration and agriculture. Very approachable math shows which populations of a CWR can best be used for restoration, and where; and also for domestication and breeding.
- An updated checklist of plant agrobiodiversity of northern Italy. Very useful use of very basic maths. Key number: only 43% of the PGR on the list are conserved ex situ.
- Cannabis, the multibillion dollar plant that no genebank wanted. No math needed to figure out weed needs a genebank.
A new genebank for the ages is set for ages
Great news from the opening ceremony of the new Future Seeds genebank in Palmira, Colombia on 15 March:
The Bezos Earth Fund pledged US$17 million for Future Seeds, a new CGIAR genebank inaugurated today. The new genebank will bolster global efforts to safeguard the world’s future food supply.
This genebank is truly next-level:
Future Seeds is the most advanced facility in Latin America and is expected to become the first ever platinum-level LEED (Leadership in Energy and Environmental Design)-certified genebank building in the world. Its Data Discovery and Biotechnology Lab will use big-data technologies to mine the genebank using the latest in genetics to document the range of possibly useful traits in the current collection. Other breakthrough technologies across genebanks include drones and robotic rovers, which are helping analyze crop characteristics in the field more rapidly, and the use of artificial intelligence to enable collectors to identify potential biodiversity hotspots in nature.
Here, check it out for yourselves:
And here’s an overview of the collections from Genesys (beans in red, cassava blue, forages green).
Full disclosure: we also support the place at work.