Helping the international community
adopt and maintain environmentally sound & sustainable practices.

|PeopleSystems and Sustainability|

Systems ecology has, as a technical field, fallen on hard times. Much research investment is made in bioengineering, nanotechnology, and cellular and subcellular biochemical and biophysical systems. We are burrowing in deeper and deeper to the structures and functions of biological systems. Along the way, though, we are losing the diverse perspective of integrative ecosystems science. The objective of this new weekly weblog on the AEHS website is to pull some of this balance back. We will dig into the big-picture of weekly issues highlighting patterns and processes at the ecosystems level as they affect the sustainability of the biosphere. The general idea is to make a small contribution to the enormous collective investment we’re going to have to make to hand a sustainable biosphere off to subsequent generations. We’ll keep the weblog brief and to the point, informal but fully documented, argumentative when necessary, collaborative at all times. Every week, we will come up with interesting, thought-provoking items and give you our perspective on them. We hope to generate an interactive weblog, where we can exchange comments and responses from week to week. Basically, a fun opportunity for all us all (especially me) to learn something and discover important issues worth thinking about. And we hope you’ll be thinking along with us. Collectively, let’s build a little more of that foundation that will help us pass a functional biosphere to our children’s children!

|About Dave|
Dave Ludwig, primary author of this weblog, was trained as a systems ecologist at the Institute of Ecology at the University of Georgia, in marine ecology at the Virginia Institute of Marine Sciences, and in Environmental Science at Rutgers University. He has worked in academia, environmental regulation, and consulting. He has published widely on urban ecology, innovative environmental assessment methods, and sustainability. He teaches online and university courses in ecology, risk assessment, and the environmental consequences of armed conflict. He is presently AEHS’ Director of Education and Training.
PeopleSystems and Sustainability: This Week in the Global Environment   
This Week in the Global Environment
Apr 21 2014 10:05AM Posted by David Ludwig, Ph.D.

A foundational problem of sustainability is that money, which drives human activities, has no currency in the ecosystem. A flux of dollars, or more generally, capital, occurs with only the investment of physical matter and energy needed for an electronic transaction. But the capital shifted in that minimalist transaction can have enormous environmental effects. Open-pit mines, forest clear cuts, blue water fishing trawls, can be triggered by a few cents-worth of electronic information exchange. Such massive environmental alterations cascade impacts through the “non-market” goods and services provided by the biosphere. Ecologists and economists struggle for ways to quantify the monetary value of nonmarket goods and services. Lack of a common grammar is just one of the issues. We have trouble rectifying conceptual maps of ecologic vs. economic parameters without generating nonsense.

The tools economists bring to this intellectual party are arithmetically intricate and putatively quantitative [1]. Hedonic price models attempt to estimate downward pressure on residential property values. Contingent valuation surveys responses to suites of hypothetical choice alternatives. Travel cost methods compare willingness-to-pay for transit to substitute sites. None of the available economic tools convincingly capture the range of goods and services inherent to functional ecosystems. Ecologists invariably see a broad range of environmental parameters needing economic accounting, while economists of necessity collapse complexity into a few simplistic categories that allow pricing.

Under some circumstances, ecological processes directly affect goods or services of known economic value, allowing valuation of ecosystem components. We may have trouble identifying the ecosystem processes associated with such prices, and the outcomes are difficult to generalize. Nonetheless, more effort to exploit price effects of recognizable ecological functions might help us address general problems of ecosystem valuation. 

For example, among the services provided by healthy ecosystems is disease suppression. While disease is of course a fact of life, damaged ecosystems tend to propagate certain illnesses, via biochemical, physiological, or landscape impairments. An easy example to think of is schistosomiasis, which tends to proliferate in rivers whose ecology is impaired by poorly conceptualized dams.

Recently, a specific disease suppression function of North American ecosystems failed. Porcine epidemic diarrhea (PED), endemic in China, appeared a year or so ago in U.S. pig populations [2]. PED causes high mortality in piglets. Since its discovery in North America in May 2013, three to four million pigs have died of the disease [3]. 

It is not known how or why PED has proliferated in the U.S. For service valuation from a systems-analytic perspective, such epidemiologic details are irrelevant. The ecological processes of pig farming ceased suppressing PED in the spring of 2013. In the intensely managed, monitored, and regulated world of pig farming, it would seem that there is an opportunity to value the function of disease suppression by measuring the economic consequences of its failure.

If only things were so simple. The economic consequences of this single, narrowly confined ecosystem service can be estimated in various ways [2][3]. Prices of retail cuts of pork are up to 13% higher than a year ago. Pork production is likely to decline by 7%. By number, the U.S. pig population will shrink by about 3%. Labor has been affected. Processors have cut up to 20% of shift work. Research and investigation investments include an immediate commitment by the pork industry of $1.7 million. Public and private sector funds are being devoted to epidemiologic studies and the search for a vaccine. Regulatory and voluntary veterinary monitoring has increased. There are costs associated with euthanasia and disposal of infected piglets. 

The challenge to anyone attempting to value PED suppression services provided by the ecosystem is selecting from among the varied monetary impacts those that are environmentally meaningful. Clearly multiple parameters reflecting different, non-overlapping aspects of PED suppression services need to be accounted. Likely a complex function, with differential weighting of single monetized parameters, would be necessary for estimating total value of such services. 

I have never seen an attempt made to convert known monetary impacts of loss or failure of specific ecosystem services into a valuation of those services. There are conceptual challenges to doing so, and estimates are likely to be mechanistically intricate and highly uncertain. However, given the present state-of-the-science—that we know qualitatively that such services exist, but then have no means to estimate quantitative outcomes—valuation efforts are important. It is not enough for us to know the identity of impaired ecosystem services. We need to understand the economic consequences of impairment. This will allow us to allocate zero-sum environmental management resources of time, money, and expertise by design, rather than by default. Sustainability depends on wise investment. 


[1] a clear, readable introduction to the conceptual foundations of environmental economics is available at



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Ocean Thermal Energy Conversion: Technological Fruit Ripe for Harvest
Mar 26 2014 3:11PM Posted by David Ludwig, Ph.D.

Decades ago, I was involved in a project establishing the engineering, economic, and environmental bounding conditions for a large Ocean Thermal Energy Conversion [OTEC] System power generating station. We were preparing a conceptual planning guide for a group of investors interested in innovating electric power production via non-fossil fuel technologies.

OTEC is an interesting, important, and (conceptually, at least) simple technology. You pump cold water from oceanic depths to the surface, where you condense a thermal exchange fluid vaporized by the warm surface waters. If sea water temperatures are stable, and your thermal exchange infrastructure efficient, you can run power-generating turbines with the vapor phase and recondense with the cold deep water in cyclical fashion. If you want to be bit more expansive, you can run an open (or hybrid) system in which the warm surface water is vaporized in a partial vacuum. With this open-cycle technology, you can generate desalinated water by collecting the vapor phase as it recondenses. 

In the 1980s, the federal Department of Energy made elaborate, pro-active preparations for the emergence of OTEC and its integration in the global power grid. Environmental impact assessment concepts were developed and published and pilot programs explored the engineering and cost parameters associated with deep water acquisition. Over time, however, the momentum of fossil-fuel exploitation overran the innovation of fledgling OTEC efforts, and the concept slipped back into obscurity. 

Today’s Washington Post (3 March 2014), in a story under the byline of Marjorie Censer, reports a revival of interest in OTEC. As large defense contractors adapt to shrinking military budgets, energy generation is an attractive buffering sector. Technological similarities—energy shares with military a foundation in hard metal and large scale—offer a pre-adapted environment for transition. According to Ms. Censer, Lockheed Martin and Chinese partners are in planning phases for an OTEC power generating station to be sited on the southern coast of China. 

Progress in OTEC is interesting and important. Environmental impacts are generally much lower than for comparable fossil fuel infrastructure. Opportunities for innovative affiliated activities—ranging from desalination to aquaculture and marine environmental restoration—abound. Effectively designed and operated OTEC facilities have the potential to not only be sustainable, but to yield clear and quantifiable net environmental benefits over their operational life (30 plus years or more, depending largely on the conformation of the condensers).

Environmental engineering in the coming decades faces incredible challenges. Global warming, fossil fuel reserves, water management, agriculture, and constraints associated with human population shifts are among the most prominent. Ocean Thermal Energy Conversion technology has real potential to not only minimize such constraints, but (if carefully planned and designed from a whole-systems perspective) to actually help resolve some of the negative outcomes usually associated with electric power generation. A rare and important focus for optimism in the complex relationship between humans and the environment. Let’s hope much more grows from this technology as we gain experience with it. It has real potential to be a multifaceted winner, a big step toward leaving our children, and their children, a cleaner, more functional biosphere.

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Fight or Flight, Spend or Save—Risk in the Real World
Mar 5 2014 8:27AM Posted by David Ludwig, Ph.D.

The interface of human social systems and the ecosystem at large is the front line in the most important conflict in the long history of the biosphere. As we work to extract food, water, and materials for our growing population, of necessity we redesign and reconfigure the environment. As the environment changes, ecological forces push back in reaction. Desertification, vectored diseases, biodiversity, and other parameters ebb and flow as the processes of human life wash against the ecosystem.

A source of friction at the PeopleSystems interface is incompatible units of measure. Like a mis-engineered Mars lander, the ecosystem operates in one set of metrics, human society in another. Biology is driven by fluxes of matter and energy. We understand ecosystems by tracing flow, storage, and transformation of molecules as organisms grow, reproduce, and interact. We measure the work and heat cascading as solar and geochemical energy are acquired and expended in the service of physiology. 

Social systems operate via flux and storage of a conceptual entity—money. Physical manifestations of money—coins, bills, digital accounts—have no foundation in the biosphere. Yet the flux of money has enormous ecosystem consequences. In today’s biosphere, cash changing hands drives the exploitation, degradation, restoration, and even maintenance of the environment. 

Much thinking and considerable research have been devoted to the meaning of money in the context of ecology. A modicum of progress has been made, but the on-the-ground facts of markets and non-market processes far outstrip our understanding. Which means, unfortunately, that we human beings own and operate the biosphere by default. We are unable to establish and pursue desired end-states for the ecosystems we inhabit because we do not know how to equate monetary social imperatives with biological processes and outcomes. 

The primary focus of environmental economics as a field of study is on finding ways to accommodate and account for non-market goods and services in a market-based social system. In this endeavor we are slow and stumbling. But it turns out there may be an even more fundamental monkey wrench clanging around the machinery linking social and ecological systems.

Vertebrate organisms share a common response to sudden, acute stress. The well-known “fight or flight” reaction is a sequential outpouring of hormones that rapidly establishes the physiological and behavioral bases for dealing with danger. Early in my career, I worked with a research team studying direct and indirect effects of pesticide chemicals on tidal marsh biota [3]. In one of our rather comedic study techniques, we would place individual fiddler crabs dosed with varying levels of organophosphates in a runway on a laboratory table, and hunker down out of the crab’s sight with a predatory clapper rail bird borrowed from the university’s taxidermy collection. On the count of three, we would suddenly push the stuffed rail up to threaten the crab, and measure the resulting panic in time and distance traveled as a dose response function. 

Slapstick science aside, the “panic” response is a universal evolutionary adaptation, one of the key tools in the eternal arms race of predator and prey. Fundamentally, it lays all the cards the prey item is holding on the table. Depending on species and circumstances, it may manifest as a mad dash for cover, a savage attack on the threatening entity, or an almost catatonic freeze-in-place intended to disarticulate the predator’s search image. 

Recent research [1], [2] suggests there is an analogous “universal” risk response in monetary social systems. High levels of stress hormones cause investors to shrink from risky investments. When high levels of cortisol flood a financier’s physiology, investment bets reflect acceptance of substantively lower levels of risk relative to potential reward. While the evolutionary basis for this is presently unknown, it is apparently a universal outcome.

It will take me some time to think through this research finding in the context of environmental management. Does it have any meaning for that rocky interface of ecology and economics? Maybe. Financial backers of, say, a new development project proposed for a controversial site where environmental sensitivity is an issue may find themselves in raucous exchanges with stakeholders and regulators. Independent of the technical risks and benefits of the proposal, individuals at the negotiating table may experience rising levels of stress hormones. Could that make investors less likely to accept the social and environmental risks of implementing the proposed action? Could it make those arguing against the proposal fix their positions at a level of concern not justified by realities of potential environmental impacts? It certainly seems possible, given the research findings. 

Negotiations over environmental risks, costs and benefits of human activities are already complex and universally involve parameters beyond those subject to resolution by objective scientific investigation. Perhaps these new research findings give us some insights applicable to such negotiations. In any case, as we understand more about the peculiar human parameters impinging on science-based decisions, the more likely we are to come to rational and effective compromise. And that can only be a good thing. 


[3] Ward, D.V., B.L. Howes and D.F. Ludwig. 1976. Interactive effects of predation pressure and 
insecticide (Temefos) toxicity on populations of the marsh fiddler crab Uca pugnax. 
Mar. Biol. 35:119-126. Ward, D.V. and B.L. Howes. 1974. The effects of Abate, an 
organophosphorus insecticide, on marsh fiddler crab populations. 
Bull. Env. Contam. Tox. 12:694-697.

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A Glimmer of Guanxi 
Nov 4 2013 7:34AM Posted by David Ludwig, Ph.D.

I made my first trip to China in the early 1990s. At the time I was along for the ride on a cross-governmental marketing visit. This rather formalized setting necessitated endless lunch and dinner banquets in various venues across the eastern third of the country. Almost every evening, the banquets involved dishes composed (we were assured by our hosts) of organisms that were “very rare. Almost none left. You are lucky to be eating some of the last in the world”. Thus, to my ongoing shame, we ate frogs, fish, snakes, turtles, birds, and mammals nominally harvested from threatened or endangered populations. 

My second trip to China was less formal and menus were more under our control. This time we didn’t eat any rare, threatened or endangered species, although we did see plenty of them in markets. 

Personal wealth is expanding at a great rate in China. And that wealth, bleeding out into world markets, has been hard on organisms that are valued in traditional folkways, for food and especially medicine. Thus great pressure accrues on tigers, rhinoceros, bears, small cats, snakes, and civets whose body parts are used in folk medicine. And fish, snakes, turtles, bats, and other animals are harvested for food. With a large human population and growing purchasing power, poaching and black markets serving China are ongoing problems for a number of species around the world. 

Guanxi is the modern Chinese word reflecting the web of personal and professional relationships embedded in the larger social system. The word conveys much more than can be easily translated by single terms in English. Guanxi encompasses friendships, favors owed and done, interpersonal histories, family ties, and more. From a systems analytic perspective, Guanxi is the process component, the flows and feedbacks among individuals in a personal network. The concept could be applied to ecological systems as a handy term for the dynamics of a network.

Recently, there is a bit of good news about the Guanxi of the network tying Chinese consumers to their food sources. The 20 October 2013 Washington Post has a front page story under the byline of Simon Denyer titled “In China, a Rare Victory for Conservation”. Specifically, the story reports that an unexpected consortium of business interests, NGOs, celebrities, students and journalists has made real headway in reducing demand for dried shark fins made into celebratory banquet soups. 

In recent years, several shark species have been severely depleted by fin collectors who habitually harvest the fins of fish from lines or nets and toss the body back in the water where the animals die a nasty death and go on to feed scavengers and decomposers. Shark fin soup is a traditional delicacy of great antiquity. Its social qualities outweigh its culinary value. I’ve eaten shark fin soup in China, Europe, Canada and the U.S. While it is interesting to unfamiliar westerners, mostly for its fine gelatinous texture, it is in fact rather bland and unexciting. The Post reports that activists, led by a San Francisco based NGO called WildAid, marshaling Yao Ming as an advertising icon and buoyed by businesspeople of conscience, have driven demand for shark fin down by 50 to 70%. Quite unexpectedly (because of the enormous diversity of celebratory mores in China and the depth to which shark fin soup is embedded in celebratory culture), political and business leaders and a substantial chunk of the general populace quickly absorbed the educational messaging and are more than willing to eschew shark fin or consume soups made with vegetable-based substitutes. 

This is a remarkable success story. It is an example of a principle of growing importance for the interaction of people and the environment. As wealth increases, people demand cleaner, more sustainable environments, and have marginal capital to invest in environmental management. 

This “Second Demographic Transition” is an unexpected and welcome outcome of economic and social systems. It means that the most effective and efficient route to sustainability lies in income equality and education. As people have the money to use more resources, they also demand that those resources be provisioned via sustainable means. 

This is in stark contrast to the more common belief that wealth and resource demands cause direct environmental degradation. In practice, it turns out that wealth drives greater investment in environmental management and application of more sustainable alternatives. 

Hopefully, we can build on the shark fin success. It is time for tiger, rhinoceros, bear and other animals to be relieved of the harvest (often illegal under international and nation-specific laws and treaties) for traditional medicine, decorative ivory, and food. 

Building the guanxi in our relations to the ecosystem-at-large is important for the future of the biosphere. Good, sustainable processes mean we’ll leave a better world for our children and their children. The shark fin example shows that we can do it, with creative activism fueled by enlightened information.
Xexe—thank you for checking in to the PeopleSystems weekly weblog. Go forth and establish some guanxi with your environment. We’ll all benefit!

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Global Warming Precedents
Oct 7 2013 11:28AM Posted by David Ludwig, Ph.D.

Anthropogenic climate warming is posited by many to have massive negative impacts on humanity and the biosphere. This may prove to be true. However, I believe there are good reasons to think that warming the global ecosystem will have net positive outcomes for people and the environment.

Applying a holistic systems framework to the problem from the human perspective, cataloging the negative impacts is insufficient analysis. Substantive economic, public health, and energy consumption benefits will accrue in a warmer world. I have yet to see such an evaluation, one which rationally compares benefits as well as costs to yield a forecast of net outcomes. A flawed but interesting and easy to read analysis of economic implications can be found in a book titled “Climatopolis: How Our Cities Will Thrive in the Hotter Future”, by Matthew E. Kahn (Basic Books of the Perseus Books Group, New York, 2010). Mr. Kahn suggests, via review of economics literature, that opportunities to gain from, mitigate, and prevent negative impacts, that society as a whole will adapt sufficiently to neutralize the impacts of a warmer biosphere. He sees this primarily as a defensive response—that science and engineering together will operate (in free market economic systems) on an offset basis to retain a status quo level of human quality-of-life. Kahn does not account for positive benefits such as increased food production, enhanced public health, reduced deterioration of infrastructure, and lower energy consumption. 

I do not agree with Mr. Kahn’s contention that free markets will be key to human response. I think nonmarket goods and services will accrue, and that standard economic analysis is unable to properly account for same. In any case, the book is worth reading. I commend it to you, and hope you will let me know your thoughts after you read it. 

From the ecological perspective, Tim Flannery explores a prehistoric period of biosphere warming in his excellent book “The Eternal Frontier: An Ecological History of North America and its Peoples” (Atlantic Monthly Press, New York, 2001). For more than 14 million years during the Eocene, the climate warmed, and for about 1 million years, ocean temperatures (and by extension the biosphere) reached unprecedented highs.

This period of warming is associated with massive changes in biodiversity and biotic standing stock. Evolutionary processes operated at dizzying (well, as dizzying as geologic-scale events can be) rates, pumping large numbers of new taxa into the biosphere. In addition, biota found it easy to spread from evolutionary centers to remote parts of the globe. The bottom line is that this time of warming climate was a time of great biodiversity. And to the degree that fossil evidence allows, it seems that biomass and/or production were also high. 
Taken together, it is possible that global warming during the twenty-first century will enhance human quality-of-life and massively increase diversity and biomass in the biosphere. 

This optimistic scenario will only be true on a large scale or “average” basis. There will without a doubt be places and times where human economy and natural ecology are subject to intense negative impacts relative to their present state. But, from a whole-system perspective, it seems to me that global warming may well bulk up the benefits side of the ledger, while shrinking the biologic and economic costs. 

What are your thoughts about the “big picture”, whole system consequences of global warming? Comment here or email me at . I’m looking forward to exchanging views! 
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Collapse of the Standard Model
Sep 3 2013 3:53PM Posted by David Ludwig, Ph.D.

In physics, the “standard model” reconciles the interactions of many subatomic particles and forces, and with the possible discovery of the Higgs Boson (mediating gravity), it may well be a successful theory, meeting its objectives and providing testable experimental questions allowing verification. In human ecology, the closest thing to a “standard model” is the theory of urbanization. As you can read in nearly every book on human development (for example, see [1]), the model runs like this: hunter-gatherers interact with their provender to yield domestic plants and animals, the resulting food surplus allows village-sized settlements and division of labor, this yields elaborated religion and temple construction, which process requires so much labor and so many people that cities begin. 

This “Neolithic revolution” was pushed to the limits with the discovery and excavation of Catalhoyuk, one of the oldest substantial human settlements, was undertaken in Turkey [2]. Catalhoyuk seemed to substantiate the “standard model”. Replete with animal bones, animal totems, and signs of animal and ancestor worship, it appeared to exemplify the power of religion and temple construction to shift into urban architecture and urban settlement, yielding one of the earliest true city ecosystems.

Another discovery in Turkey, several hundred kilometers to the west of Catalhoyuk, recently seems to have collapsed that “standard model”. 
On an otherwise unremarkable hilltop, an elaborate stone temple complex, with multiple walled ovals surrounding enormous stone pillars vaguely human-shaped, carved with stunning representations of local game, wildlife, and predators, has been identified and explored [3]. The astonishing thing about Gobekli Teppe is its age—11,000 years old, predating Stonehenge by some 6,000 years. 

Archaeologist Klaus Schmidt has discovered, furthermore, that the engineers and visionaries who constructed and worshipped at Gobekli Teppe were not a stable agricultural society—the time period predates agriculture. Furthermore, remains excavated from the ruins confirm: the people of Gobekli Teppe were hunter-gatherers.

Now, admittedly, the location, in the north of the fertile crescent, was a region of food abundance. From wild einkorn wheat to herds of gazelles and aurochs, food was available and the people took full advantage. But the impact of Gobekli Teppe on the “standard model” comes from its clearly out-of-sequence placement on the continuum from agriculture to temple to city. Gobekli Teppe, with its deeply complicated ceremonial foundations (involving the recovery of human skulls from buried cadavers, for ancestor worship, and the subjugation of wild animals from their position as small carvings on large human representations) originated directly from hunter-gatherers.

Hunter-gatherers were not supposed to have the time, the division of labor, the intellectual sophistication, and certainly not the engineering skills, to produce such a stone monument. But it’s not “a stone monument”. It’s an entire religious complex, covering thousands of square meters of ground. And it is layered—it was in use for thousands of years.

And here’s what really brings the “standard model” into question. The entire temple complex was buried, after a period of shrinking size and utility, by its people. Probably because, the religious role of Gobekli Teppe was exported over time to places like Catalhoyuk. Absent Gobekli Teppe, Catalhoyuk can be seen to support the standard model. With Gobekli Teppe, Catalhoyuk and other cities of its time actually seem to be products of religion and settlement and stone construction skills long thought to be beyond the language and physical and intellectual resources of hunter-gatherers. 
Human ecosystems have been pushed at least 6,000 years deeper into the past than we have thought for centuries. It is an exciting time to be considering urban ecosystems. I can’t wait for the next jolt to our present notions of the constraints of human culture and human transformation of the landscape! 

[1] Mumford, L. 1961. The City in History. Copyright renewed 1989. Harcourt, Inc. NY.
[2] Balter, M. 2005. The Goddess and the Bull. Free Press, NY. Hodder, I, 2006. The Leopard’s Tale, Thames and Hudson Ltd, London. 
[3] accessed 3 August 2013. 

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Malaria: Progress in the Face of History
Aug 26 2013 12:52PM Posted by David Ludwig, Ph.D.

Silent Spring. Touchstone of environmental management, wake-up call for millions. The focus of Silent Spring was on the broadcast spraying of DDT for pest insect control. Subsequently, the technical literature documented the food-web accumulation of DDT from the days of widespread application, and the decline in such concentrations after cessation.

DDT isn’t always bad. In malarial regions (which are expected to expand substantively with global warming), indoor residual spraying (of eves and ceilings) is an important component of malaria control, saving thousands of lives every year. Presently, the human health risks and benefits of indoor DDT spraying balance out on the side of continued application [1]. But there is growing concern for human health risks, even when DDT is applied properly. And in the long-term, the equilibrium level of malaria cases, despite indoor residual DDT use, remains at relatively high levels.

Recently, there has been a breakthrough in malaria control [2]. Researcher Stephen Hoffman engineered weakened sporozoites via irradiation in situ in the mosquito host. The sporozoites were extracted by dissection, and administered intravenously to a test cohort of 40 people. At the highest vaccine dose, 100% of the test subjects were successfully protected from malaria. 

Logistically, this vaccine still leaves us quite a distance from the finish line of effective malaria control. Dissecting sporozoites from individual irradiated mosquitoes is a clear impairment to wide use. As is the IV administration, and the need for five sequential doses. 

Still, as Anthony Fauci points out in the Post piece, these are engineering problems. They are solvable by technological means. This is as close as we’ve gotten to a workable malaria vaccine. The concept is simple and robust. We’re only separated from a viable vaccine by scale-up challenges, which are, admittedly, formidable. Still, the human costs of malaria globally are enormous. Addressing those costs, and the prospect of reducing DDT use in indoor residual spraying, are important incentives. This is an opportunity we cannot afford to pass up. We must pursue this vaccine, and pursue it hard. 


[1] See Bouwman et al. 2011 at

[2] reported by Michael Gerson, op ed “Closer to a Malaria Breakthrough?” in the Washington Post13 August 2012. 

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Ickiness, Well Documented
Aug 7 2013 9:21AM Posted by David Ludwig, Ph.D.
Human civilization is festooned with closely coevolved fellow travelers. Where people go, commensals, parasites, and disease organisms follow. And their impact on urban ecosystem patterns and processes are not trivial. Rats and mice vector diseases and compete with us for food resources. Cats and dogs hunt the rodents, but leave substantial pollutants via urine and feces, and vector other diseases. Starlings, pigeons, and house sparrows are ubiquitous and suppress populations of native birds. Insects from roaches to flies (including mosquitoes) are pests and disease vectors themselves. Mites and nematodes dwell in, on and around us to the degree that yields the parasitology aphorism that “if you took away all the anthropogenic things in the biosphere except mites and nematodes, you’d be left with a ghostly three dimensional model” of the biosphere. And the microbial community of human ecosystems is phenomenally diverse and productive.

There are many ways to view and investigate the people-dependent components of the larger ecosystem. An interesting and important aspect that is in general under-studied is the relationship of pests and parasites to social status and wealth of their individual human hosts. Dawn Biehler at the University of Maryland Baltimore County (UMBC) has tackled this relationship in a creative and up-to-date survey, a study about to be published as a book titled “Pests in the City: Flies, Bedbugs, Cockroaches, and Rats” by the University of Washington Press. A well-written summary of the book, with insights into Biehler’s methods and objectives, is available in the summer 2013 UMBC Magazine. Based on that preliminary read, and given the obvious importance and immediate relevance of the subject, I recommend that the book be read by a wide audience, including educated lay city dwellers along with scientists and urban ecosystem specialists. I have my copy pre-ordered, and I commend the book to you, whether or not your specialty has any direct relationship to urban ecosystems. We all depend on the social and physical functioning of cities. This book will provide important insights into one of the many monkey wrenches on its way into the ecosystem machinery.

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Locking and Loading the Landscape Weapon
Jul 23 2013 8:45AM Posted by David Ludwig, Ph.D.

Throughout history, manipulation of land and water have been part of the arsenal that human beings apply to each other in war and other acrimonious relationships. Classic cases include flooding via dam breaching (as in the World War Two bombing of upstream dams on the Ruhr River), wildfire (burned crops and croplands in Russia and the Ukraine during World War Two), landform reconfiguration (the enormous anti-tank trenches around Kuwait in the early 1990s) and others. 

One matter not usually viewed as an issue of war and weaponry is the Irish potato famine of the 1840s. The ecological facts are straightforward. Over time, millions of Irish farmers switched from diverse crops and crop cycles characteristic of smallholding farms to potatoes. And not just any potatoes. Cheap, vulnerable potato varieties, grown mostly for export. It was the English, at the time nominal overlords of Ireland, who shunted Irish agriculture into potatoes. According the Washington Post (book review dated 13 January 2013), the English saw the potato famine as a necessary offset to an inherent “laziness” of the Irish, and also as a way to solve some of their own regional overcrowding by moving people from densely populated areas to parts of Ireland recently rendered under-populated. Two excellent books on the topic came out early this year. American John Kelly published The Graves Are Walking: The Great Famine and the Saga of the Irish People (published by Henry Holt); and Tim Pat Coogan published The Famine Plot: England’s Role in Ireland’s Greatest Tragedy (Palgrave Macmillan). 

These books take different analytical approaches. Kelly is driven by cold facts and documents the “nuts and bolts” of the potato famine. Coogan is more polemic, perhaps befitting an Irish historian. 

The facts are that Irish farms by the 1840s eschewed crop diversity and grew potatoes. And only potatoes. And only one variety of potatoes. The result, when a fungus Phytophthora infestans hit and spread, was an ongoing sequence of crop failures. By 1851, Ireland’s population was reduced from more than eight million people to about six and a half million. And the country has yet to recover. The population remains below the level of 1845.

Basically, the English instituted a system that virtually assured mass starvation and emigration. Basic ecological principles tell us that intensive and large scale monoculture of an inherently physiologically weak crop will result in crop failure. In general, a year of crop failure would trigger a response in the form of more diverse plantings going forward. In mid-19th century Ireland, the farms continually planted potatoes. Year after year. And crop failures occurred year after year. The English accomplished their bizarre objective of depopulating Ireland simply by assuring that a single, vulnerable crop was monocultured for decades. Big problem, easily predictable and easily solved, if the English had any interest in “solving” it. 

Landscape manipulation as a large-scale weapon continues deep into the twenty-first century. In Vietnam in the 1970s, the U.S. applied infamous herbicide Agent Orange to denude forested lands. In Africa in the Sudan and Somalia, factional warfare includes crop destruction, land ruination, and usurpation of arable areas. 

In most wars, ecosystem degradation is an outcome. In Ireland in the 1840s, it was a weapon. A weapon that continues in use. This illustrates a fundamental problem of ecosystems science. Our work is filtered through political and social systems. It doesn’t take an ecologist to apply the landscape weapon. But repairing, restoring, or eliminating landscape weaponry definitely requires ecological expertise. As far as I know, there is no uniformed service of ecologists to play these issues out during war. Perhaps it is time to rethink this. The National Oceanic and Atmospheric Administration, a component of the U.S. Department of Commerce, has a uniformed service of vessel operators. Maybe the U.S. Department of Defense needs an ecological services branch to monitor and respond to weapons oriented application of the biosphere. An odd thought, I know. But one that seems to be of growing utility in a world where wars are now mostly local or regional and susceptible to such weaponry. With a little forethought, USDOD might innovate to obviate or neutralize landscape weapons. 

What do you think? Is there a role for ecology in wartime military? This presumably means continual support of ecologists in peacetime as well. But the investment might well be worthwhile. The case of England and Ireland illustrates why!

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Aerial Plankton: Good, Bad, Ugly, or Indifferent?
Jul 23 2013 8:37AM Posted by David Ludwig, Ph.D.

Ecologists make their way into some obscure corners of the biosphere. Examples? How about the study of Mural Vegetation, in this case “Mural” meaning “wall”? There is indeed an active, if small, community of researchers who study the ecosystems of vertical surfaces, most (but not all) of human origin. Another is fossil cave dung. Much has been learned by deconstructing and reconstructing the ecology of fossilized ground sloth dung, and the debris piles left by rodents in certain caves, mostly in South America but also in Africa. And human commensal invertebrates have a technical following. Did you know that there is at least one species of nematode found only in beer mats in German bars? And that about 75% of human beings are colonized by “eyelash mites”, tiny arthropods that live at hair follicles and apparently survive by absorbing nutrients from the semi-liquid goo generated at the root of the hair.

But we could do this for page after page. One seemingly obscure aspect of the biosphere that has been favored for study sporadically over the decades is aerial plankton. I turns out that the atmosphere is populated by an amazing abundance and diversity of microscopic life. Recently, Popular Science provided a brief report on aerial plankton surveys conducted by researchers at the Georgia Institute of Technology in Atlanta, GA, USA (fair disclosure: my youngest son is a student at Georgia Tech). Basically, by filtering air while flying at 6 miles altitude, investigators determined that about 20% of the total particles were not only biological in origin, they are living cells! The atmosphere is not purely a physical and chemical phenomenon. It is biologically active, and linked in potentially important ways to other components of the biosphere. For example, among the cells identified, E. coli bacteria are present. Likely swirled into the atmosphere by hurricane cells over cities, it might well be the case that diseases are spread over vast distances by aerial plankton. 

Since any atmospheric particles are associated with weather, clearly bacterial aerial plankton play a role—unquantified and uncharacterized to date—in determining weather conditions. It is possible that there is a functional nutrient cycling in situ, affecting the chemical composition of precipitation and therefore its quality and quantity. 

Without much more investigation (particularly hypothesis generation and testing), it is impossible to say whether or not aerial plankton is more than an inert oddity. But at the biomass and diversity levels reported by the Georgia Tech researchers, this seems unlikely. It appears to me that there is much potential for important processes, unknown to date, to be occurring at high atmospheric altitudes. 

I encourage you all to formulate some working and testable hypotheses next time you find yourself cruising at high speed and high altitude on your way to a technical colloquium, project meeting, vacation and R&R, whatever. This is one of the few remaining scientific endeavors to which meaningful contributions can be made simply by thinking. Take advantage of it when you can!

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