Threats

June 30, 2008June 30, 2008

The perils of protected areas

Does it make sense to conserve crop wild relatives in situ? That’s an extreme way of asking the question, I know, but maybe it is worth putting it as starkly as possible. To concentrate minds, let us say. Such musings were triggered (not for the first time) by the latest niche modelling study trying to predict what will happen to species distributions under climate change.

As usual, it’s not good. Working on the California flora, researchers at Berkeley found “that two thirds of … ‘endemics’ could suffer more than an 80% reduction in geographic range by the end of the century.” The average shift in range will be 150 km, and in many cases there will be no overlap between the old and new ranges. Current hotspots of diversity will disappear. That’s in line with studies more focused specifically on crop wild relatives.

However, “[t]he authors [also] identified several ‘climate-change refugia’ scattered around the state. These are places where large numbers of the plants hit the hardest by climate change are projected to relocate and hang on.”

The usual caveats apply. In particular, the exact results for a given species will depend on whether it can migrate and/or adapt fast enough to track changing climates. But let’s think it through. The global strategy for crop wild relatives conservation says we should

Identify globally, and within each region, a small number of priority sites (global = 100, regional = 25) for the establishment of active CWR genetic reserves.

Let’s assume we identify such a site, because of its interesting or high diversity, say. What would really be the best way of conserving the population(s) found there? If migration is fast enough to track climate across the landscape, surely it would be best to conserve the population ex situ, rather than moving the protected area every once in a while.

If migration cannot keep up with climate, there are only two possible outcomes. Either the population dies out, in which case of course ex situ is the only option. On the other hand, if adaptation occurs, and the population persists, the selection pressure is likely to be so strong and so centred on temperature and water availability, that many useful alleles for other non-climate related traits are likely to be winnowed out. Again, you’d probably want to conserve the population ex situ anyway.

So I guess the answer to the question I started out with is a heavily qualified affirmative. Yes, it does make sense to conserve crop wild relatives in situ. BUT. Only if you also do it ex situ, and only if you do it with a view to what distributions are likely to look like in a hundred years’ time. We should all be looking for those “climate change refuges.” But we should also be collecting those crop wild relatives as fast and as completely as possible.

June 25, 2008June 25, 2008

Nibbles: Homegardens, Rice, Fish, Climate change, Value chains, Fuel costs, Urban drift

Uganda: “Many youth are no longer idle. They grow vegetables and sell them.”
Iran: “Rice is becoming a luxury for many of the poor, just like meat and chicken.”
California: “In nearly every scenario we explored, biodiversity suffers...”
Australia: “the Australian Fish Names Standard AS SSA 5300 which prescribes standard fish names approved for use in Australia.”
Pretty much anywhere: “linking small-scale producers to modern markets.”
Dept. of Silver Linings: “Fuel Costs May Force Some Kids To Walk.” Via.
Tibet: “I’ve lived here long enough.” Via.

June 24, 2008

Commission embraces agricultural biodiversity?

This news item out of the European Commission seems to be very important, so I think I’m justified in reproducing it in full below, especially as the specific item does not yet have a url all to itself (though there is a fairly general one):

The Commission adopted on Friday June 20 a proposal that will help preserve biodiversity. Member States had already endorsed the proposal in mid April. The proposal to protect seed varieties of agricultural crops, which may be threatened by genetic erosion, will also enable small plant breeding companies to supply local markets with naturally adapted seed varieties. These seed varieties are mostly old locally used varieties threatened by extinction.

The proposal foresees derogations from the EU seed marketing legislation for seed varieties that are naturally adapted to local conditions, but which currently cannot be marketed because they do not fulfil certain criteria. Under EU legislation, seed varieties must undergo an approval process and get listed on the national and common seed catalogues before they can be marketed within the territory of the EU. These rules ensure that EU farmers have access to high quality seed. Certain varieties, which are not found on these catalogues, are still important to ensure that plant genetic diversity is not diminished. The Commission has therefore proposed that these varieties could be placed on the catalogues without official examination, once they meet some minimum standards.

Jeremy has blogged several times about this. I guess the devil will be in the detail, but it does look encouraging. Anyone have more information?

June 22, 2008July 7, 2009

Sorghum endures

How much crop genetic diversity have we lost? At one level, the question is easy to answer: three quarters over the last century. That’s certainly the number that’s most often quoted.

But that doesn’t make it right. In particular, I have it on very good authority that the figure may in fact be traceable back — a la Chinese whispers — to a statement in Fowler & Mooney’s 1990 book Shattering: “As the mid-1970s were reached, three-quarters of Europe’s traditional vegetable seed stood on the verge of extinction.”

Not quite the same thing. Anyway, be that as it may, the existence of a dominant narrative hasn’t stopped people going out into the field and — the horror! — actually collecting data.

Continue reading “Sorghum endures”

June 19, 2008June 23, 2008

UG99: The Phantom Menace?

Very good news from the United States Department of Agriculture. Breeders are about to release the first wheat lines that incorporate several genes for resistance to UG99, the new race of rust fungus that threatens wheat worldwide. One line will be available to growers on the east coast of the US. All will be available to breeders worldwide to develop new varieties adapted to local conditions.

Part of the effort leading to the new wheats has been a screening of more than 5000 accessions from several genebanks. One outcome of this massive evaluation exercise has been the discovery that UG99 had overcome many more resistance genes than original estimates. That’s why it has been important to pyramid several resistance genes into the new varieties. Just where those resistance genes came from I don’t know. But the USDA does say that the breeders “also will develop new sources of genetic resistance to rusts from three wild relatives of wheat”.

Good luck to them. Certainly the wheat farmers of Iran, ((I cannot resist a quick aside. At the FAO high-level meeting a couple of weeks ago one of the Iranian delegates dropped by my stall. I struck up a conversation.

Was he worried about UG99?
No, our scientists can control it.
Really? Where can I find out more?
They have communicated with the Authorities.
Really? Where can I find out more?

And so it went, with neither of us making much progress, and I was reminded mostly of the golden age of Stalinist genetics, an oxymoron if ever there was one.)) Pakistan, Afghanistan and northern India — the current front in the fight against UG99 — need all the help they can get. But a tiny part of me really rather hopes that the new varieties are not in fact a success.

The world badly needs another demonstration of the power of pests and diseases to destroy food supplies and the importance of agricultural biodiversity to protect us from them. Southern corn blight is the poster child for the value of diversity.

That outbreak more or less created the modern move to conserve crop diversity in genebanks, a move that has lost its impetus as the world forgets that food security requires the ready availability of lots and lots of agricultural biodiversity.

So while I am truly glad that breeders are making progress against UG99, I’d also like to see UG99 make real inroads into the developed world’s wheat crops, just as a reminder, lest they forget. ((I stole the Sith from here. If it is copyrighted, I apologise. Contact me, and I’ll remove it.))