Archive for May, 2006

Pollution risks Yangtze’s ‘death’

Published by Garry Peterson on May 30, 2006 in Greenlash, Ideas and Regime Shifts. 1 Comment

From BBC news, Pollution risks Yangtze’s ‘death’, briefly describes China’s fears that how large scale eutrophication and pollution is impacting human wellbeing and economic growth prospects along the Yangze.

YangtzeThe Yangtze, China’s longest river, is “cancerous” with pollution, reports in the country’s state media have said.Environmental experts fear pollution from untreated agricultural and industrial waste could turn the Yangtze into a “dead river” within five years.

That would make it unable to sustain marine life or provide drinking water to the booming cities along its banks.

The Yangtze rises in China’s western mountains and passes through some of its most densely populated areas.

The government has promised to clean up the Yangtze, which supplies water to almost 200 cities along its banks.

But experts speaking in China’s state media say that unless action is taken quickly, billions of tonnes of untreated industrial and agricultural waste and sewage are likely to kill what remains of the river’s plant and wildlife species within five years.

China’s rapid economic development means that many of the nation’s waterways are facing similar problems.

Last year the authorities announced that the country’s second-longest river, the Yellow River, was so polluted that it was not safe for drinking.

Correspondents say that 300 million people in China do not have access to safe drinking water.

They say that government efforts to clean up the country’s polluted lakes and waterways are being thwarted by lax enforcement standards.

Does Rainfall Increase in the Sahel Mask a Degradation Trend?

Published by Line Gordon on May 30, 2006 in Ecological Management, Regime Shifts and Vulnerability. 0 Comments

There have been heated debates about the dynamics of land degradation and climate change in the Sahel region in West Africa. The region has suffered a number of extreme droughts since the 1960’s causing famine, loss of livestock and reduced vegetation. However, a ‘greening trend’ trend has recently been detected. To a large extent this trend appears to be driven by increased rainfall (although some scientists argue that this alone can not explain the full extent of the greening trend).

Several studies, based on remote sensing, have now analyzed the reduced vegetation during the drought years and compared it to current land cover. Interestingly, they have not detected any land degradation that can be attributed to land management, which is in contrast with earlier studies suggesting that livestock management in the region is reducing productivity and increasing the systems vulnerability to drought.

A recent paper ‘Desertification in the Sahel: a reinterpretation’ by Hein and De Ridder published in Global Change Biology, suggests that the analyses based on remote sensing may be flawed and that land degradation may have been masked by rainfall.

Hein and De Ridder’s reasoning builds on the way that previous studies linked net primary production (NPP) (or actually a vegetation index - NDVI) to rainfall. These previous studies assumed that for a given site with no land degradation a linear relationship exists between NPP and rainfall (i.e. the Rain Use Efficiency (RUE) is constant). When they did not see any change in RUE over time they assumed that there has not been any land degradation.

Hein and De Ridder studied RUE in six field sites and found that in the absence of land degradation the relationship between NPP and rainfall was non-linear (followed a quadratic curve). When they looked at expected RUE values based on their quadratic estimates they found that the RUE from satellite estimates were lower than the expected ones, and thus land degradation may have occurred. They conclude:

If anthropogenic degradation of the Sahel is demonstrated, this would have repercussions for the debate on the causes of climate change in the Sahel. Currently, a weakness in the argumentations … that anthropogenic land cover changes have contributed to the occurrence of the extreme Sahelian droughts of the last decades of the 20th century is a lack of evidence of degradation from remote sensing data. Hence, if new remote sensing analyses confirm anthropogenic degradation, this would support the hypothesis that degradation of the vegetation layer, in particular through sustained high grazing pressures, has contributed to the occurrence of the 20th century droughts in the Sahel. Furthermore, if degradation of the Sahelian vegetation cover is confirmed, this would indicate that Sahelian pastoralists may be more vulnerable for future droughts than currently assumed. Because degradation of the Sahel in the 1980s and 1990s has been masked by an upward trend in annual rainfall, the consequences of a future drought for the local population could be unexpectedly severe.

Designing Resilient Software?

Published by Garry Peterson on May 24, 2006 in Design and Tools. 0 Comments

Daniel Jackson has written an article, Dependable Software by Design, on how software design tools can be used to improve the resilience of software. In Scientific American he wrote:

An architectural marvel when it opened 11 years ago, the new Denver International Airport’s high-tech jewel was to be its automated baggage handler. It would autonomously route luggage around 26 miles of conveyors for rapid, seamless delivery to planes and passengers. But software problems dogged the system, delaying the airport’s opening by 16 months and adding hundreds of millions of dollars in cost overruns. Despite years of tweaking, it never ran reliably. Last summer airport managers finally pulled the plug–reverting to traditional manually loaded baggage carts and tugs with human drivers. The mechanized handler’s designer, BAE Automated Systems, was liquidated, and United Airlines, its principal user, slipped into bankruptcy, in part because of the mess.

…Such massive failures occur because crucial design flaws are discovered too late. Only after programmers began building the code–the instructions a computer uses to execute a program–do they discover the inadequacy of their designs. Sometimes a fatal inconsistency or omission is at fault, but more often the overall design is vague and poorly thought out. As the code grows with the addition of piecemeal fixes, a detailed design structure indeed emerges–but it is a design full of special cases and loopholes, without coherent principles. As in a building, when the software’s foundation is unsound, the resulting structure is unstable.

…Now a new generation of software design tools is emerging. Their analysis engines are similar in principle to tools that engineers increasingly use to check computer hardware designs. A developer models a software design using a high-level (summary) coding notation and then applies a tool that explores billions of possible executions of the system, looking for unusual conditions that would cause it to behave in an unexpected way. This process catches subtle flaws in the design before it is even coded, but more important, it results in a design that is precise, robust and thoroughly exercised. One example of such a tool is Alloy, which my research group and I constructed. Alloy (which is freely available on the Web) has proved useful in applications as varied as avionics software, telephony, cryptographic systems and the design of machines used in cancer therapy.

Daniel Jackson has also recently written a book Software Abstractions: Logic, Language, and Analysis. The book’s website describes the book:

Daniel Jackson introduces a new approach to software design that draws on traditional formal methods but exploits automated tools to find flaws as early as possible. This approach–which Jackson calls “lightweight formal methods” or “agile modeling”–takes from formal specification the idea of a precise and expressive notation based on a tiny core of simple and robust concepts but replaces conventional analysis based on theorem proving with a fully automated analysis that gives designers immediate feedback. Jackson has developed Alloy, a language that captures the essence of software abstractions simply and succinctly, using a minimal toolkit of mathematical notions. The designer can use automated analysis not only to correct errors but also to make models that are more precise and elegant. This approach, Jackson says, can rescue designers from “the tarpit of implementation technologies” and return them to thinking deeply about underlying concepts.

via ThreeQuarksDaily

Ecology for Transformation

Published by Garry Peterson on May 22, 2006 in Big Back Loop, Ideas, Reorganization and Scenarios. 1 Comment

David Zaks and Chad Monfreda write on Worldchanging on Steve Carpenter and Carl Folke’s 2006 paper in Ecology for Transformation (doi.org/10.1016/j.tree.2006.02.007):

Ecology has long been a descriptive science with real but limited links to the policy community. A new science of ecology, however, is emerging to forge the collaborations with social scientists and decision makers needed for a bright green future. Stephen Carpenter and Carl Folke outline a vision for the future of ecology in their recent article, Ecology for Transformation. You need a subscription to access the full article, so we’ll quote them at length:

“Scenarios with positive visions are quite different from projections of environmental disaster. Doom-and-gloom predictions are sometimes needed, and they might sell newspapers, but they do little to inspire people or to evoke proactive forward-looking steps toward a better world. Transformation requires evocative visions of better worlds to compare and evaluate the diverse alternatives available to us … Although we cannot predict the future, we have much to decide. Better decisions start from better visions, and such visions need ecological perspectives.”

Ecology for Transformation offers the perspective of resilient social-ecological systems. Simply put, it recognizes that ecosystems and human society are interdependent, and that they need the capacity to withstand and adapt to an increasingly bumpy future.

Examples of resilient social-ecological systems abound in all kinds of notoriously difficult to manage areas, like natural disaster response and rangeland management. Resilience sounds great, but how do we get there? Fortunately Carpenter and Folke offer a theoretically robust three-part transformative framework:

1. Diversity
2. Environmentally sound technology
3. Adaptive governance

Diversity constitutes the raw material we can draw from to create effective technologies and institutions. It reflects the wealth of genetic and memetic resources at our disposal, in the form of biodiversity, landscapes, cultures, ideas, and economic livelihoods. We need to foster diversity as an insurance package for hard times because…

“…crisis can create opportunities for reorganizing the relationships of society to ecosystems. At such times, barriers to action might break down, if only for a short time, and new approaches have a chance to change the direction of ecosystem management. To succeed, a particular approach or vision must be well-formed by the time the crisis arises, because the opportunity for change might be short-lived.”

Environmentally sound technology ranges from incremental advancements in energy efficiency to innovative economic tools like natural capital valuation and markets for ecosystem services. Diversity and technology should sound familiar enough to WorldChanging readers. Ecology for transformation, however, goes on, to challenge us to engage in adaptive governance that recognizes the reality of constant change. The authors define adaptive governance as:

“Institutional and political frameworks designed to adapt to changing relationships between society and ecosystems in ways that sustain ecosystem services; expands the focus from adaptive management of ecosystems to address the broader social contexts that enable ecosystem based management.”

Governance is much broader than what we normally think of as government and encompasses all of the actors who shape the way we work, live, and interact. Communication across various scales, from individuals to institutions, is vital for effective governance. Many of the management and governance structures currently in place are static, but an ‘adaptive’ approach promises more sustainable outcomes by negotiating uncertainty and change.

Steve Carpenter, WA Brock, and I addressed the issue of how scientists can encourage transformations by creating new management models in our 2003 paper Uncertainty and the management of multistate ecosystems: an apparently rational route to collapse (Ecology. 84(6) 1403-1411). We wrote:

…scientists can contribute to broadening the worldview of ecosystem management in at least three ways.

(1) Scientists can point out that uncertainty is a property of the set of models under consideration. This set of models is a mental construct (even if it depends in part on prior observation of the ecosystem). It therefore depends on attitudes and beliefs that are unrelated to putatively objective information about the ecosystem. Despite this discomforting aspect of uncertainty, it cannot be ignored.

(2) Scientists can help to imagine novel models for how the system might change in the future. There will be cases where such novel models carry non-negligible weight in decision, for example when the costs of collapse are high. The consequences of candidate policies can be examined under models with very different implications for ecosystem behavior. Such explorations of the robustness of policies can be carried out when model uncertainty is quite high or even unknown, for example in scenario analysis.

(3) Scientists can point out the value of safe, informative experiments to test models beyond the range of available data. In the model presented here, fossilization of beliefs follows from fixation on policies that do not reveal the full dynamic potential of the ecosystem, leading to the underestimation of model uncertainty. Experimentation at scales appropriate for testing alternative models for ecosystem behavior is one way out the trap. Of course, largescale experiments on ecosystems that support human well being must be approached with caution. Nevertheless, in situations where surprising and unfavorable ecosystem dynamics are possible, it may be valuable to experiment with innovative practices that could reinforce desirable ecosystem states.

I think our second point, the need for creative synthesis, is not emphasized enough in science, which tends to focus on testing existing models. Ecological governance needs new ways of thinking about nature that are useful in governance situations. The creation of novel, practical models is a vital part of connecting science to policy and action. Without practical models, people are unable to develop desirable policy or effective actions.

Thoughts on Simple and Complex Causes of Lumps

Published by Buzz Holling on May 21, 2006 in Ideas. 0 Comments

Reply of Buzz Holling to a message from Marten Scheffer:

I did like your models (Scheffer and van Nes) that show that lumps of species emerge naturally from competition, augmented with predation (see post on self-organization of ecosystem lumpiness). I like also that the simulated lumpy distributions you demonstrated are very evolutionarily robust. That is what has been shown in so much of the multi species community data and experimental manipulations that have been published by various authors.

But let me offer some other empirical evidence that suggest something else may ALSO be operating. Then I’ll end with some words on the philosophy of science!

First, in one of my tests in my “lumpy paper” I asked if herbivores and carnivores had different lump patterns among the mammals in each of the communities of the boreal prairies and boreal forests (Holling, C.S. 1992. Cross-scale morphology, geometry and dynamics of ecosystems. Ecological Monographs. 62(4):447-502). In my mind, this was a crude, crude test of the role of competition and predation in forming body mass lump patterns. Herbivores and carnivores turned out to have the same lump patterns, suggesting that something more than competition must be causing the similarity.

Second, I asked if mammals compared to birds in the same communities (boreal forests and boreal prairies) had different or similar lump patterns. It turned out that the patterns differed when compared by untransformed masses, but were very similar when the bird masses were expressed as Mass to the third power and mammal masses as untransformed mass. Birds, it was argued, therefore must see their world in three dimensions, and mammals in one dimension. Some behavioral data seems to conform to that conclusion. But note the data and tests only applied to two systems, and clearly more ecosystems need to be compared. Adding bats, mammals that fly, offers a set of additional tests that would be very valuable. Data, however, are tough to get. Such tests need data on masses of birds, non flying mammals and bats from the same ecosystem communities.

Third , one of my colleagues, Jan Sendzimir, asked if body mass lump patterns among birds or mammals in different ecological communities around the world were more similar if they came from the same type of community. In essence, for example, are lump patterns in boreal forest communities in Europe and North America more similar to each other than to patterns among totally different communities? The answer was that they were more similar to each other, even when comparing different continents. That suggests that patterns on landscapes over a wide range of scales is central in defining lumpy patterns.

Fourth, Craig Allen has discovered a remarkably consistent pattern that the masses of endangered and invasive species of birds and mammals, exist disproportionately on the edge of the body mass lumps. He has shown that for at least five ecosystems around the world. It is as if crisis and opportunity are shared there, where, I suppose, the resources available at those scale breaks were poor. As scales increase, points are reached where the available resources suddenly change. (Think of viewing a high resolution satellite image of a landscape at different powers of ten from meters to tens of thousands of kms). Initially you see leaves and branches , and suddenly a scale is reached where you see trees and vegetation types- and on and on. What you see, I thought, is what you can , potentially eat or , better, utilize).

Finally, I am delighted with your emphasis on self organization. I have long felt that self organization , integrated with Darwinian evolution, has huge explanatory power, and the combination answers many of the existing puzzles of evolution.

But I also felt that the self organizing patterns were ones that involved not just interactions among biological species of similar trophic relations (like your competitors) but also interactions across trophic categories , and even interactions among organisms and abiotic features. Maybe, I thought, that is why anoxid, pre Cambrian organisms evolved the ability to use the dreadful poison of oxygen to explosively release a new burst of evolution. I imagined oxygen breathing species evolving in water where diffusion of oxygen was slow enough that local concentrations could be built up by organisms with facultative oxygen metabolism. Suddenly anoxic metabolism there becomes a penalty and oxygen metabolism a huge benefit. From those local concentrations, a world with oxygen could bloom.

There are two very distinct ways to suggest and test such ideas. One is via models, where very specific causes are designed and tested as a deductive excercise. That is what your paper does, in a significant expansion of that tradition. The other comes from a larger scale of testing of whole assemblies of potentially interacting variables . The conceptual ideas might come from earlier models. That was what my lump paper attempted as a test of a set of conclusions comparing earlier simulation models of ecosystems. Each of about a dozen models /studies indicated a small number of variables (less than five) at distinctly different scales explained those systems changes in variables. Hence I suggested, real data covering broad scales should show a small number of lumpy clusters. Body mass was chosen as a test because that is the data that are available. The data indeed showed the lumpy structure.

Now what is needed is slightly expanded deductive models with up to five variables/processes, much like those that Steve Carpenter and Buz Brock have structured for economic-ecological mini systems (see papers in Ecology and Society on lakes and fishing). And much more testing is needed with large scale assemblies of variables as I attempted in my lump paper. That is what Craig Allen has been doing, with collaborators, for a number of systems- biological, ecological , economic and social,. A book is about to be published, I believe. He might have some revealing comments that we all could learn from.

C.S.Holling

Punctuated Equilibrium in Environmental Policy

Published by Steve Carpenter on May 16, 2006 in Ideas, Regime Shifts and Reorganization. 0 Comments

Readers familiar with panarchy theory will find a rich set of relevant examples in a new book edited by Robert Repetto, Punctuated Equilibrium and the Dynamics of U.S. Environmental Policy.

In Chapter 2, Frank Baumgartner explains how U.S. environmental policy shows is static for long periods of time, reflecting stable institutional structures, shared understanding of goals, and balance of power among competing interests. Occasionally, however, there are bursts of innovation as public policies are radically restructured. These rare but crucially important bursts of innovation occur across a range of scales, from local to national. Baumgartner makes his case using statistical case histories of policy dynamics.

William Brock, in Chapter 3, explains social and economic mechanisms that cause long periods of stasis interrupted by bursts of enormous change in environmental policy. Brock uses minimal models grounded in well-established social and economic phenomena. The remainder of the book develops case studies in depth.

Some cases have undergone radical change: management of water in California, certain marine fisheries, and timber in the Pacific Northwest. Other systems seem locked in traps: greenhouse gas and climate policy, vehicular fuel economy standards, and livestock grazing on public lands. History suggests that these traps will eventually be broken.

In his introductory chapter, Repetto summarizes the positive and negative feedback mechanisms that underlie punctuated equilibrium. He writes:

Though they [the feedback mechanisms] are fully capable of explaining the observed patterns of stability and abrupt change, their workings are difficult to predict in particular policy struggles because of their complex interactions. The infrequency of policy breakthroughs suggests that most efforts to bring them about will fail. Entrenched interests and ideology will retain their dominance; challengers will be unable to gather sufficient resources, attention, and momentum. Nonetheless, such failed efforts may build a foundation for later success when conditions are more favorable by undermining the prevailing policy image, by mobilizing new interests, and by forming new coalitions. Even knowing that the odds are long, effective policymakers continue to work on their issues in order to be ready and primed when opportunities arise. Timing is crucial . . . . Across the broad range of resource and environmental policy issues, only a few, if any, are likely to have potential for significant change at any particular time. The ability to discern which ones these are is a vital strategic skill.

This pattern is well known to researchers familiar with adaptive cycles and panarchy. Surprisingly, this scholarly and well-documented volume has almost no references to research on adaptive cycles, resilience and panarchy. The lone exception is a citation to the 2002 Panarchy book edited by Gunderson and Holling. I hope that there is more exchange of ideas on punctuated policy dynamics and panarchy in the future.