Tag Archives: agriculture

Ecological Economics, Regime Shifts

Food security and financial markets

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FAO says that Food price volatility a major threat to food security:

Concluding a day-long special meeting in Rome the experts recognized that unexpected price hikes “are a major threat to food security” and recommended further work to address their root causes.

The recommendations, put forward by the Inter-Governmental Groups (IGGs) on Grains and on Rice, came as FAO issued a report showing that international wheat prices have soared 60-80 percent since July while maize spiked about 40 percent.

The meeting said that “Global cereal supply and demand still appears sufficiently in balance”, adding, “unexpected crop failure in some major exporting countries followed by national policy responses and speculative behaviour rather than global market fundamentals have been the main factors behind the recent escalation of world prices and the prevailing high price volatility.”

Among the root causes of volatility, the meeting identified “Growing linkage with outside markets, in particular the impact of ‘financialization’ on futures markets”. Other causes were listed as insufficient information on crop supply and demand, poor market transparency, unexpected changes triggered by national food security situations, panic buying and hoarding.

The Groups therefore recommended exploring “alternative approaches to mitigating food price volatility” and “new mechanisms to enhance transparency and manage the risks associated with new sources of market volatility”.

In a recent IFPRI discussion paper, Recent Food Prices Movements: A Time Series Analysis, Bryce Cooke and Miguel Robles analyze the food price spike of 2008.  They asses multiple proposed explanations (from biofuels, oil prices, weather, trade barriers, and speculative markets) using econometric time series analysis.  They conclude that financial activity in futures markets and proxies for speculation can best explain crisis.  They write:

Results of our rolling windows Granger causality tests show the following:

(1) In the case of rice prices we find weak evidence that for few 30-month intervals between 2004 and 2007, the U.S. dollar depreciation rate has marginally Granger-caused the growth rate of rice price; and also the growth rate of real world money holdings seems to be more important in explaining the growth rate of rice prices after 2004, but this evidence is not really statistically significant.

(2) When we analyze the price of soybeans we find that, starting in mid-2005 (which implies a 30-month period ending December 2007), the growth rate in the world exports of soybeans shows evidence of Granger causing the growth rate of soybean prices.

(3) In the case of corn we find that starting in the second half of 2004 the growth rate of oil prices shows evidence of Granger causing the growth rate of corn prices, but with a negative relationship.

(4) When analyzing our speculation proxies we observe that the ratio of monthly volume to open interest in futures contracts indicates that for the case of wheat and rice, starting in 2005, it has influence in forecasting price movements.

Also we find that for the case of rice, the ratio of noncommercial long positions to total long (reportable) positions has an effect on prices, starting in 2004. When we analyze the same ratio for short positions we find additional evidence for speculation affecting the growth rate of corn and soybean prices. In the case of corn there are signs of causality between March 2004 and September 2006, and during the 30-month span from May 2005 to November 2007. In the case of soybeans we find weak evidence, in particular for the 30-month period ending February 2008.

Interestingly as the rolling samples include 2008 and 2009 data, picking the decrease of grain prices since mid 2008 and the adverse effects of the global financial crisis, the evidence of speculation activity affecting spot prices vanishes in all cases. This supports the view that during the food crisis agricultural grain markets were operating under a different regime in which speculation activity played a role in spot prices formation. The overall evidence points to the following interpretation: before and after the food crisis speculation activity had no effect on spot prices formation while during the crisis it did. This is not to say that before and after the crisis speculation was not present, it was (probably to a less extent) but didn’t granger cause spot prices.

Overall, we conclude from our time series analysis that when taking the four commodities analyzed here there is evidence that financial activity in futures markets and/or speculation in these markets can help explain the behavior of these prices in recent years. Other explanations are only partially supported for the particular case of one agricultural commodity or not supported at all. We do not claim, however, that these other explanations should be disregarded; all that we can say is that in using the variables considered in this study and the particular time series models herein, we do not find such evidence.

Frederick Kaufman wrote a Harper’s magazine in July 2010 The food bubble:
How Wall Street starved millions and got away with it that reports on finance and the food crisis. The Harper’s version is behind a paywall, but Kaufman was interviewed on Democracy Now.

More academic takes on the food crisis and the possible future of food price volatility are in:

C. Gilbert and C. Morgan’s article Food price volatility in Proc Royal Soc (DOI: 10.1098/rstb.2010.0139 ). They conclude:

We have highlighted the extensive evidence demonstrating interconnection of financial and food commodity markets as the result of speculative activity. Nevertheless, this contention remains controversial and, until the mechanisms are better understood, the policy debate will remain confused.

and

C. Gilbert’s How to Understand High Food Prices in Journal of Agricultural Economics (DOI: 10.1111/j.1477-9552.2010.00248.x) whose abstract states:

Agricultural price booms are better explained by common factors than by market-specific factors such as supply shocks. A capital asset pricing model-type model shows why one should expect this and Granger causality analysis establishes the role of demand growth, monetary expansion and exchange rate movements in explaining price movements over the period since 1971. The demand for grains and oilseeds as biofuel feedstocks has been cited as the main cause of the price rise, but there is little direct evidence for this contention. Instead, index-based investment in agricultural futures markets is seen as the major channel through which macroeconomic and monetary factors generated the 2007–2008 food price rises.

Ecological Economics, Ecosystem services, Millennium Ecosystem Assessment

Untangling the Environmentalist’s Paradox

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My colleagues are I recently published a paper in BioScience, Untangling the Environmentalist’s Paradox: Why Is Human Well-being Increasing As Ecosystem Services Degrade?

The paper originated from the involvement of the first four authors, my former PhD student Ciara Raudsepp-Hearne, my colleague at McGill Elena Bennett, and my former post-doc Maria Tengö and I, in the Millennium Ecosystem Assessment.  While we were all happy with our work on the MA, we felt that the MA had not had enough time to digest its findings.  I was particularly interested in the apparent contradiction between the MA’s assumption that ecosystem services are essential to human wellbeing and the observation that human wellbeing has been increasing as ecosystem services decline.

Our paper compares four alternative explanations of this apparent contradiction.  Our abstract outlines the paper:

Environmentalists have argued that ecological degradation will lead to declines in the well-being of people dependent on ecosystem services. The Millennium Ecosystem Assessment paradoxically found that human well-being has increased despite large global declines in most ecosystem services. We assess four explanations of these divergent trends: (1) We have measured well-being incorrectly; (2) well-being is dependent on food services, which are increasing, and not on other services that are declining; (3) technology has decoupled well-being from nature; (4) time lags may lead to future declines in well-being. Our findings discount the first hypothesis, but elements of the remaining three appear plausible. Although ecologists have convincingly documented ecological decline, science does not adequately understand the implications of this decline for human well-being. Untangling how human well-being has increased as ecosystem conditions decline is critical to guiding future management of ecosystem services; we propose four research areas to help achieve this goal.

BioScience has highlighted the article by writing a press release, providing a set of teaching resources, and featuring the article in the issue’s editorial.  BioScience’s editor-in-chief Timothy M. Beardsley writes:

… BioScience will publish commentary on aspects of their analysis in a future issue. Yet the article clearly strengthens the case for research that integrates human well-being, agriculture, technology, and time lags affecting ecosystem services. Raudsepp-Hearne and her colleagues urge more attention to how ecosystem services affect multiple aspects of well-being, ecosystem service synergies and trade-offs, technology for enhancing ecosystem services, and better forecasting of the provision of and demand for ecosystem services.

The recent oil calamity in the Gulf of Mexico, the biological impacts of which will take years to fully manifest and will persist for decades, should be reminder enough that although technology can insulate us from degrading ecosystem services locally, it often does so by creating problems elsewhere. As the human population grows, fewer places remain where the impacts can be absorbed without adversely affecting somebody. Aggregate global human well-being is, apparently, growing—though it is obviously declining in some places. Extending and defending the gains, particularly as the quest for energy becomes more intense, will require policymakers to understand the complicated relationship between ecosystem services and the humans who use them.

I’ll summarize our paper and respond to some of the media coverage of our paper in followup posts.

The paper is:

  • Ciara Raudsepp-Hearne, Garry D. Peterson, Maria Tengö, Elena M. Bennett, Tim Holland, Karina Benessaiah, Graham K. MacDonald, and Laura Pfeifer.  2010. Untangling the Environmentalist’s Paradox: Why Is Human Well-being Increasing As Ecosystem Services Degrade? BioScience. 60(8) 576-589.

Thanks to BioScience an open access version is temporarily available here.

Ecosystem services

Brazilian agriculture

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1)The Economist writes about the success of large scale Brazil agriculture in Brazilian agriculture: The miracle of the cerrado. The article concludes:

The bigger question for them is: can the miracle of the cerrado be exported, especially to Africa, where the good intentions of outsiders have so often shrivelled and died?

There are several reasons to think it can. Brazilian land is like Africa’s: tropical and nutrient-poor. The big difference is that the cerrado gets a decent amount of rain and most of Africa’s savannah does not (the exception is the swathe of southern Africa between Angola and Mozambique).

Brazil imported some of its raw material from other tropical countries in the first place. Brachiaria grass came from Africa. The zebu that formed the basis of Brazil’s nelore cattle herd came from India. In both cases Embrapa’s know-how improved them dramatically. Could they be taken back and improved again? Embrapa has started to do that, though it is early days and so far it is unclear whether the technology retransfer will work.

A third reason for hope is that Embrapa has expertise which others in Africa simply do not have. It has research stations for cassava and sorghum, which are African staples. It also has experience not just in the cerrado but in more arid regions (called the sertão), in jungles and in the vast wetlands on the border with Paraguay and Bolivia. Africa also needs to make better use of similar lands. “Scientifically, it is not difficult to transfer the technology,” reckons Dr Crestana. And the technology transfer is happening at a time when African economies are starting to grow and massive Chinese aid is starting to improve the continent’s famously dire transport system.

Still, a word of caution is in order. Brazil’s agricultural miracle did not happen through a simple technological fix. No magic bullet accounts for it—not even the tropical soyabean, which comes closest. Rather, Embrapa’s was a “system approach”, as its scientists call it: all the interventions worked together. Improving the soil and the new tropical soyabeans were both needed for farming the cerrado; the two together also made possible the changes in farm techniques which have boosted yields further.

Systems are much harder to export than a simple fix. “We went to the US and brought back the whole package [of cutting-edge agriculture in the 1970s],” says Dr Crestana. “That didn’t work and it took us 30 years to create our own. Perhaps Africans will come to Brazil and take back the package from us. Africa is changing. Perhaps it won’t take them so long. We’ll see.” If we see anything like what happened in Brazil itself, feeding the world in 2050 will not look like the uphill struggle it appears to be now.

2) On the Agricultural Biodiversity Weblog Luigi responds to the Economist article, in a post Is there really no downside to Brazil’s agricultural miracle?.  He praises their coverage of agriculture, but lambasting their blindness to the consideration of social and ecological costs.  He writes:

It points out that the astonishing increase in crop and meat production in Brazil in the past ten to fifteen year — and it is astonishing, more that 300% by value — has come about due to an expansion in the amount of land under the plow, sure, but much more so due to an increase in productivity. It rightly heaps praise on Embrapa, Brazil’s agricultural research corporation, for devising a system that has made the cerrado, Brazil’s hitherto agronomically intractable savannah, so productive. It highlights the fact that a key part of that system is improved germplasm — of Brachiaria, soybean, zebu cattle — originally from other parts of the world, incidentally helping make the case for international interdependence in genetic resources.1 And much more.

What it resolutely does not do is give any sense of the cost of all this. …  I was really thinking of environmental and social costs. The Economist article says that Brazil is “often accused of levelling the rainforest to create its farms, but hardly any of this new land lies in Amazonia; most is cerrado.” So that’s all right then. No problem at all if 50% of one of the world’s biodiversity hotspots has been destroyed.2 After all, it’s not the Amazon. A truly comprehensive overview of Brazil’s undoubted agricultural successes would surely cast at least a cursory look at the downside, if only to say that it’s all been worth it.

3) Holly Gibbs and colleagues have a new paper in PNAS – Tropical forests were the primary sources of new agricultural land in the 1980s and 1990s (doi/10.1073/pnas.0910275107).  They write:

This study confirms that rainforests were the primary source for new agricultural land throughout the tropics during the 1980s and 1990s. More than 80% of new agricultural land came from intact and disturbed forests. Although differences occur across the tropical forest belt, the basic pattern is the same: The majority of the land for agricultural and tree plantation expansion comes from forests, woodlands, and savannas, not from previously cleared lands.

Worldwide demand for agricultural products is expected to increase by ~50% by 2050, and evidence suggests that tropical countries will be called on to meet much of this demand. Consider, for example, that in developed countries the agricultural land area, including pastures and permanent croplands, decreased by more than 412 million ha (34%) between 1995 and 2007, whereas developing countries saw increases of nearly 400 million ha (17.1%) (14, 42). Moreover, developing countries expanded their permanent croplands by 10.1% during the current decade alone, while permanent cropland areas in developed countries remained generally stable (14). If the agricultural expansion trends documented here for 1980 2000 persist, we can expect major clearing of intact and disturbed forest to continue and increase across the tropics to help meet swelling demands for food, fodder, and fuel.

Ecosystem services, Visualization

Aquatic Dead Zones

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      I’ve published several links to global maps of coastal hypoxia. Now, NASA has produced a new map of global hypoxic zones, based on Diaz and Rosenberg’s . Spreading Dead Zones and Consequences for Marine Ecosystems. in Science, 321(5891), 926-929.  NASA’s EOS Image of the Day writes on  Aquatic Dead Zones.

      Red circles on this map show the location and size of many of our planet’s dead zones. Black dots show where dead zones have been observed, but their size is unknown.

      It’s no coincidence that dead zones occur downriver of places where human population density is high (darkest brown). Some of the fertilizer we apply to crops is washed into streams and rivers. Fertilizer-laden runoff triggers explosive planktonic algae growth in coastal areas. The algae die and rain down into deep waters, where their remains are like fertilizer for microbes. The microbes decompose the organic matter, using up the oxygen. Mass killing of fish and other sea life often results.

      General

      Short links: agricultural statistics

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      1) FAO is granting free and open access to its central data repository, FAOSTAT, the world’s largest and most comprehensive statistical database on food, agriculture, and hunger.

      2) FAO statistics on production of crops, fruits, livestock, oil crops, and others can be analyzed in Gapminder.

      3) How many plants feed the world on Agricultural Biodiversity weblog.  They write:

      Instead, they worked with national level Food Balance Sheets from FAO, and looked at the question in four ways to determine just how many species make up 90% of the total intake of food weight, calories, protein and fat in each country.

      The result is “85 species commodities and 28 general commodities contribute 90% of national per capita supplies of food plants.” After a bit of tinkering, they come up with this final statement: “the total number of species commodities is 82. These consist of 103 species. Fifty-six of the species commodities, consisting of 75 species, account for 5% or more of the national supply of a nutritional category in at least one country.”

      4) International Development Statistics is an online database of the volume, origin and types of aid and resource flows to over 150 developing countries. The data are collected from official statistical reports submitted to the OECD by members of its Development Assistance Committee and include figures on official development assistance, other official flows and private funding.

      Ecological Management, Ideas

      Food history: Social change & tortilla technology

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      On the weblog Edible Geography Nicola Twilley presents a talk by and profile of Rachel Laudan, a historian of food, at Fueling Mexico City: A Grain Revolution:

      All cities require fuel: oil, gas, electricity, and so on. What I want to talk about today is the energy that fuels the people in the cities—food. Without food energy, a city is nothing. A city is nothing without the people who work and play and enjoy or suffer through the city, and they require food.

      I want to talk in four short bursts. The first is about what all cities need in the way of food. The second is the reason why Mexico City had a particularly hard time with food. The third describes a revolution in the food of Mexico City that has taken place in the twenty years since I first saw it. And the fourth is about the kind of trade-offs that had to be made to undergo that revolution in food.

      On her own blog Rachel Laudan writes about why the Columbian exchange was a non-event in culinary history:

      Ok, what do I mean by culinary history?  Culinary (from the Latin culina, kitchen) history traces the history of the (guess) the kitchen or more generally, the techniques used to turn plants and animals into food.

      Thesis. 1492 (or the Columbian Exchange) is a complete non-event in culinary history.

      Why?  Well, the kitchens and techniques that went from Old World to New were imposed on top of older Mesoamerican techniques.  The result was a two-tier cuisine.  The Spanish kitchen for those of Spanish ancestry, the Mexican kitchen for everyone else.

      Or water mills, copper pots, bench stoves, bread ovens for the first lot, grindstones, pottery, three stones round the hearth to balance a griddle, for the latter.  Result–a thin layer of Catholic European Cuisine spread over the local cuisines.

      More important what about the kitchens and techniques that went from the New World to the Old.  Zilch, nada. …

      Consider three culinary techniques that the Old World could have picked up.

      1.  Treating maize with an alkali.  The culinary advantage.  You can make a flexible flatbread with this.  Preferred by most people to the porridges and gruels that were the common way of eating maize in the Old World, maize not treated with alkali not lending itself to flat or raised bread preparations.

      2. Making a vegetable puree sauce.  Eventually the Old World figured out how to do this with tomatoes.  But not with chiles, not as thickeners, and not with tomatillos which give a lovely acid taste and great thickening power.  Very little use of rehydrated dried chile in this capacity. Where are the tomatillos in Europe?  Where are the chiles used as the thickeners and flavorers of sauces (instead of simply as  a piquant taste).

      3.  Turning cacti/agave into really useful foods.  The paddle cactus is perfect as a green vegetable and grows in arid regions.  The agave yields a drinkable liquid in arid regions and can be turned into a syrup or an alcohol without much trouble.  Yet although these now grow all over the arid regions of Eurasia they are used at most as animal food.

      But not a one.  So far as I know, no cooks were brought over from the New World, no systematic exploitation of processing methods from that part of the world.

      Ecological Management, Greenlash

      GMO crops and shifting agricultural food webs

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      A recent paper by Yanhui Lu and others in Science (DOI: 10.1126/science.1187881) shows how ecological impacts of Bt cotton at the landscape level have lead to a surge in pests. In northern China, the cotton crop is 95% Bt cotton.  The paper shows that Mirid bugs have increased both within cotton fields, but also in other crops grown in regions with large amounts of Bt cotton.

      While the farmers who planted GMO cotton have benefited from it, the increase regional pest load has imposed a burden on other farmers who do not grow Bt cotton – a negative externality. This regional impact on other crops is shown in Figure 4 from their paper.

      Association between mirid bug infestation levels in either cotton or key fruit crops, and Bt cotton planting proportion. The measure of mirid bug infestation was assigned a score ranging from 1 (no infestation) to 5 (extreme infestation).

      While this is the first paper, which I’m aware of, to demonstrate such landscape level impacts of GMOs on insect pests, this type of consequence of Bt GMO crops has been predicted for a long time.  For example, ten years ago I argued in Conservation Ecology that risk assessment of GMO crops should include not only direct impacts, but indirect ecological impacts, as part of an adaptive risk assessment processes for GMO crops. Below is Figure 1 from that paper.

      The direct and indirect effects of genetically modified crops interact with the scale at which they are grown to determine the difficulty of predicting, testing, and monitoring their potential impacts.

      The Agricultural Biodiversity Weblog comments on the paper, and SciDev.net reports Bt cotton linked with surge in crop pest:

      Their fifteen-year study surveyed a region of northern China where ten million small-scale farmers grow nearly three million hectares of Bt cotton, and 26 million hectares of other crops. It revealed widespread infestation with mirid bug (Heteroptera Miridae), which is destroying fruit, vegetable, cotton and cereal crops. And the rise of this pest correlated directly with Bt cotton planting.

      Bt cotton is a genetically engineered strain, produced by the biotechnology company Monsanto. It makes its own insecticide which kills bollworm (Helicoverpa armigera), a common cotton pest that eats the crop’s product — the bolls. …

      …

      They watched the farms gradually become a source of mirid bug infestations, in parallel with the rise of Bt cotton. The bugs, initially regarded as occasional or minor pests, spread out to surrounding areas, “acquiring pest status” and infesting Chinese date, grape, apple peach and pear crops.

      Before Bt cotton, the pesticides used to kill bollworm also controlled mirid bugs. Now, farmers are using more sprays to fight mirid bugs, said the scientists.

      “Our work shows that a drop in insecticide use in Bt cotton fields leads to a reversal of the ecological role of cotton; from being a sink for mirid bugs in conventional systems to an actual source for these pests in Bt cotton growing systems,” …

      Nature news reports:

      The rise of mirids has driven Chinese farmers back to pesticides — they are currently using about two-thirds as much as they did before Bt cotton was introduced. As mirids develop resistance to the pesticides, Wu expects that farmers will soon spray as much as they ever did.

      Two years ago, a study led by David Just, an economist at Cornell University at Ithaca, New York, concluded that the economic benefits of Bt cotton in China have eroded. The team attributed this to increased pesticide use to deal with secondary pests.

      The conclusion was controversial, with critics of the study focusing on the relatively small sample size and use of economic modelling. Wu’s findings back up the earlier study, says David Andow, an entomologist at the University of Minnesota in St Paul.

      “The finding reminds us yet again that genetic modified crops are not a magic bullet for pest control,” says Andow. “They have to be part of an integrated pest-management system to retain long-term benefits.”

      Whenever a primary pest is targeted, other species are likely to rise in its place. For example, the boll weevil was once the main worldwide threat to cotton. As farmers sprayed pesticides against the weevils, bollworms developed resistance and rose to become the primary pest. Similarly, stink bugs have replaced bollworms as the primary pest in southeastern United States since Bt cotton was introduced.

      …

      Wu stresses, however, that pest control must keep sight of the whole ecosystem. “The impact of genetically modified crops must be assessed on the landscape level, taking into account the ecological input of different organisms,” he says. “This is the only way to ensure the sustainability of their application.”

      Ecological Management, Ecosystem services

      Agriculture – breeding, biodiversity and biomass

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      1) Lack of research to improve yields in non-industrial agriculture. The Agricultural Biodiversity Weblog comments on What are breeders selecting for?:

      A new paper by H.E. Jones and colleagues compares cultivars of different ages under organic and non-organic systems, and concludes that modern varieties simply aren’t suited to organic systems.

      2) The environmentalism of the poor. The poor want biomass not biodiversity is the unsurprising result on a new literature review from the Nature Conservancy reports SciDev.net.

      “People just don’t care about biodiversity,” said Craig Leisher of the US-based Nature Conservancy, at the meeting, ‘Linking biodiversity conservation and poverty reduction: what, why and how?’ held at the UK’s Zoological Society of London.Leisher, who conducted the research with Neil Larsen, also from the Nature Conservancy, gave the example of a poor fisherman, for whom the route out of poverty is to catch more fish — not more kinds of fish. …

      But Matt Walpole, head of the UN Environment Programme’s Ecosystem Assessment Programme, and an author of the Science study, warned that the finding that biomass was more important than biodiversity was context-specific.

      “If one thinks in terms of consumptive use then amount is important,” he said. But in agriculture, for example, biodiversity is important.

      “Variability allows adaptability to variations in the ecosystem … if you’ve got variation then you are more resistant to shocks.”

      3) Agriculture vs. Fish. On Nature’s Climate Feedback blog Olive Heffernan reports on PISCES Conference:

      Jake Rice and … economist Serge Garcia, are concerned that measures to conserve marine biodiversity are in contradiction with policies to protect food security, with the likely upshot that both will fail to address their respective goals.

      The conundrum is straightforward: by mid-century, there’ll be an additional 2 billion people on earth, each of whom will need to eat. In total, they’ll require an extra 3.65*108 of dietary protein. Forecasts suggest that we’ll need an 11% increase in irrigation for grain production just to keep pace with human population growth, not withstanding the impacts of climate change on crops and water availability. Right now, one-third of the world’s population relies on fish and fisheries products for at least one-fifth of their annual protein intake; if that continues to be the case, we’ll need around 70 million metric tonnes more fish protein by 2050, says Rice.

      That’s something like 75-100% of current fish protein production. So how can we generate this and manage our fisheries? Rice outlines several possible options, each of which involves a conflict with environmental management. …

      The problem, says Rice, is that these clearly conflicting policy goals aren’t being looked at by the same people at a high enough level. Now that the old problem of fisheries governance is being met with the newer problems of climate change and rapid population growth, we need a merger of these discussions, he says. He’d like to see the Convention on Biological Diversity pay more attention to the sustainable food dimension of their mandate and the Food and Agricultural Organization speaking with the CBD at a higher level. Eventually, says Rice, the UN General Assembly should be the forum to look at merging and prioritizing these policies.

      General

      Ecological memory of Amazonian agriculture

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      I just wrote this note on Faculty of 1000 on the paper (doi:10.1073/pnas.0908925107) I mentioned the other day:

      Pre-Columbian agricultural landscapes, ecosystem engineers, and self-organized patchiness in Amazonia
      McKey D, Rostain S, Iriarte J, Glaser B, Birk JJ, Holst I, Renard D
      Proc Natl Acad Sci U S A 2010 Apr 12  [related articles]

      This fascinating study describes how ecological engineers (such as ants, termites, and earthworms) maintained a newly described pre-Columbian agricultural landscape. The authors describe sites along the Guianan coastal plain (in Guyana, Suriname, and French Guiana) where pre-Columbian farmers constructed raised fields in flat, marshy locations.

      The paper is particularly interesting because it combines new archaeological evidence in favour of the relatively new, and somewhat controversial, idea of a fairly densely settled pre-Columbian Amazonia with an ecological analysis of i) how spatial self-organization of ecosystems was likely used by pre-Columbian agriculturalists to enhance the yield and resilience of their agriculture system and ii) how these same processes have preserved aspects of the agricultural system during about five centuries of abandonment. This study is also interesting for its demonstration of how ecological memory can maintain patterns produced by past disturbance (whether natural or human), and in its hints of how different types of agriculture that work with biodiversity could possibly be reinvented today.

      Some photos from the supplementary info of the paper:


      Pre-Columbian raised fields in the Guianas. (A–D) Pre-Columbian raised fields in coastal French Guiana are located in flooded depressions, in flat savannas, along sandy ridges, or in talwegs. (A) Piliwa, on the left bank of the Mana River in extreme western French Guiana. (B) Corossony, on the left bank of the Sinnamary River. (C) K-VIII, west of the city of Kourou, near the Bois Diable site. (D) Maillard, between the town of Macouria and Cayenne Island.


      (E) Map of raised-field complexes along coastal Amazonia from eastern Guyana to near Cayenne in French Guiana.

      Ecological Management, Networks

      Short Links: Networks, Amazonian historical ecology, and development data

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      Two recent papers and comments + a new data site:

      1) Tom Fiddaman on a new Nature paper (doi:10.1038/nature08932) from Eugene Stanley‘s lab on cascading failure in connected networks, that shows that feedbacks between connected networks can destabilize two stable networks.

      2) Wired news article Lost Tribes Used Clever Tricks to Turn Amazon Wasteland to Farms by Brandon Keim, who is writing a book on ecological tipping points,describes recent research on  newly discovered remains on novel agricultural systems in the coastal Amazon.  Its based on a paper by  Doyle McKey and others in PNAS –  Pre-Columbian agricultural landscapes, ecosystem engineers, and self-organized patchiness in Amazonia (doi:10.1073/pnas.0908925107.  The paper is really cool, combing an exploration of ecological memory with historical ecology. From  the abstract:

      … we show that pre-Columbian farmers of the Guianas coast constructed large raised-field complexes, growing on them crops including maize, manioc, and squash. Farmers created physical and biogeochemical heterogeneity in flat, marshy environments by constructing raised fields. When these fields were later abandoned, the mosaic of well-drained islands in the flooded matrix set in motion self-organizing processes driven by ecosystem engineers (ants, termites, earthworms, and woody plants) that occur preferentially on abandoned raised fields. Today, feedbacks generated by these ecosystem engineers maintain the human-initiated concentration of resources in these structures. Engineer organisms transport materials to abandoned raised fields and modify the structure and composition of their soils, reducing erodibility. The profound alteration of ecosystem functioning in these landscapes coconstructed by humans and nature has important implications for understanding Amazonian history and biodiversity. Furthermore, these landscapes show how sustainability of food-production systems can be enhanced by engineering into them fallows that maintain ecosystem services and biodiversity. Like anthropogenic dark earths in forested Amazonia, these self-organizing ecosystems illustrate the ecological complexity of the legacy of pre-Columbian land use.

      3) The World Bank has launched a new web site: data.worldbank.org to provide free access to development data. Their data catalog provides access to over 2,000 indicators from World Bank data.