Tag Archives: Buzz Holling

No surprise to Buzz Holling: Non-linear response of seabirds to forage fish depletion

Guest post from Henrik Österblom from the Stockholm Resilience Centre.

Basic ecology rests firmly on a number of basic assumptions.  Some of these assumptions, specifically how predators interaction with their prey, were developed by a key figure in the history of resilience – Buzz Holling. The Holling type I, II and III functional responses are standard material in many textbooks in ecology (here’s wikipedia on functional response).  The different functional responses reflect the prey consumption ratio as a function of food density.  I learned about these different types of functional response more than a decade before coming across anything related to resilience theory, which is perhaps not surprising as the first papers published by Holling on the topic came out in the late 1950s (Holling 1959).

The different functional responses reflect different ways in which predator consumption of prey varies  with changes in food density. The functional response is also related to the numerical response – the reproduction rate in relation to food abundance. If this is too technical, bear with me.

Different types of functional response.

As shown above, a type I functional response is linear – meaning that more prey means that more prey are consumed – straightforward and simple. A type II response is non-linear – the number of prey consumed/reproduction increases initially but reaches a plateau at a certain prey density, as the predator ability to consume prey is gradually saturated. A type III response is more complex and S shaped, with a slow increase in prey consumed/reproduction, due to difficulty in discovering  prey, followed by an increase and subsequent leveling off, as predators are saturated (for more background see here).

What has all this got to do with seabirds?

Seabirds are some of the most conspicuous components of the marine environment and are also well studied throughout the world. Many places where seabirds are studied also have monitoring programs for their prey. Seabirds prey on small pelagic, fat schooling fish – some of which are very important in the rapidly growing aquaculture and meat production sectors.

Recently, I was part of a large group of scientists who analyzed long-term data collected of seabird breeding success, for a range of seabird species breeding throughout the world, including puffins, murres, gulls and penguins. Several of these data sets had previously indicated a type I, or possibly a type II response in some instances, but the evidence were inconclusive. However – when putting all the data together, an interesting pattern emerged – the data indicated a clear type II response!What was even more interesting was that this response was consistent across ecosystems and species.  All ecosystems and species investigated had a very similar level of the threshold – regardless of latitude or foraging strategy. Although we assumed that there would be some nonlinear response in all ecosystems and species, we did not think the threshold would be so similar in where it was located (i.e., at one third of the maximum observed fish biomass).

The key figure from our paper is below.

Fig. 2 (A) Relationship between normalized annual breeding success of seabirds and normalized prey abundance. Each data point from all the time series was plotted with the predictions of a generalized additive model (GAM) (solid line). The gray area represents the 95% confidence interval of the fitted GAM. The threshold in the nonlinear relationship (black solid vertical line) and its 95% confidence interval (black dashed vertical lines) were detected from a change-point analysis. (B) Change in variance across the range of normalized food abundance ranging from –1.5 to 2 standard deviations in eight classes. Variance below the threshold was 1.8 times higher than above it. (C and D) Similar relationships were present when data were pooled (C) for species within ecosystems and (D) for species pooled among ecosystems using the best-fitting asymptotic model (table S2). The Arctic Tern (not shown) model fit was not significant (table S1). The colors in (A) and (C) represent the data set for each ecosystem and in (D) for each seabird species.

The findings, just published in Science (Cury et al. 2011), show that seabirds are unable to increase their breeding output over a certain prey abundance. However, if the amount of prey falls below a threshold – which we estimated at one third of the observed maximum prey abundance – breeding success drops dramatically. This non-linear response has potentially important implications for management: If forage fish stocks are maintained above the identified threshold – seabird breeding success is likely sustainable. However, if fish stocks are harvested to below this level for extended periods of time, we are likely to observe decreasing breeding success and decreasing seabird populations. The study suggests that the one-third rule of thumb can be used as a precautionary guiding principle for marine management. So, potentially, we can use some basic principles from ecology to arrive at some basic principles for marine resource use.

The study highlights the importance of curiosity driven research and long term monitoring program. These monitoring programs were not primarily intended to inform management of marine resources but were instead set up by individuals with a keen interest in basic seabird ecology The study also underlines the importance of multidisciplinary collaboration for producing fun and exciting syntheses. Most of all, it highlights how rewarding it is to work with seabirds – coolest critters on the planet.  Seabirds occupy some of the most remote and harsh habitats on the planet and are incredibly resilient – until critical thresholds are passed.


Cury, P.M., Boyd, I.L., Bonhommeau, S., Anker-Nilssen, T. Crawford, R. J. M., Furness, R.W., Mills, J.A., Murphy, E.J., Österblom, H., Paleczny, M., Piatt, J.F., Roux, J.-P., Shannon, L., Sydeman, W.J., 2011 Global Seabird Response to Forage Fish Depletion —One-Third for the Birds. Science 334 (6063), December 23. (DOI: 10.1126/science.1212928 )

Holling, C. S. 1959. The components of predation as revealed by a study of small-mammal predation of the European pine sawfly. Canadian Entomologist 91: 293-320

Resilience and Euro – diversity

On MacroEconomic Resilience ex-banker Ashwin Parameswaran draws upon Holling’s pathology of natural resource management and the work of Hyman Minsky (a connection I’ve mentioned previously and Ashwin has explored extensively – see here and here) to write about The Resilience Stability Tradeoff: Drawing Analogies between River Flood Management and Macroeconomic Management.

Ashwin Parameswaran insightfully writes:

In complex adaptive systems, stability does not equate to resilience. In fact, stability tends to breed loss of resilience and fragility or as Minsky put it, “stability is destabilising”. Although Minsky’s work has been somewhat neglected in economics, the principle of the resilience-stability tradeoff is common knowledge in ecology, especially since Buzz Holling’s pioneering work on the subject. If stability leads to fragility, then it follows that stabilisation too leads to increased system fragility. As Holling and Meffe put it in another landmark paper on the subject titled ‘Command and Control and the Pathology of Natural Resource Management’, “when the range of natural variation in a system is reduced, the system loses resilience.” Often, the goal of increased stability is synonymous with a goal of increased efficiency but “the goal of producing a maximum sustained yield may result in a more stable system of reduced resilience”.

The entire long arc of post-WW2 macroeconomic policy in the developed world can be described as a flawed exercise in macroeconomic stabilisation. But there is no better example of this principle than the Euro currency project as the below graph (from Pictet via FT Alphaville) illustrates.

Instead of a moderately volatile mix of different currencies and interest rates, we now have a mostly stable currency union prone to the occasional risk of systemic collapse. If this was all there is to it, then it is not clear that the Euro is such a bad idea. After all, simply shifting the volatility out to the tails is not by itself a bad outcome. But the resilience-stability tradeoff is more than just a simple transformation in distribution. Economic agents adapt to a prolonged period of stability in such a manner that the system cannot “withstand even modest adverse shocks”. “Normal” disturbances that were easily absorbed prior to the period of stabilisation are now sufficient to cause a catastrophic transition. Izabella Kaminska laments the fact that sovereign spreads for many Eurozone countries (vs 10Y Bunds) now exceed pre-Euro levels. But the real problem isn’t so much that spreads have blown out but that they have blown out after a prolonged period of stability.

Stockholm Resilience Centre talks on iTunes

Sturle Hauge Simonsen from Stockholm Resilience Centre has told me that you can freely download Centre seminars and presentations from iTunes. Many shorter presentations are available on YouTube.

Speakers in the iTunes talks includes a diverse group of well known scientists such as Elinor Ostrom, Buzz Holling, Claire Kremen, Pavan Sukhdev, Frances Westley, Terry Hughes, Karen O’Brien, and Johan Rockström.  In total there are over 50 talks by a multi-disciplinary set of sustainability science researchers, including me.

You can download iTunes for free here. Once you have downloaded and opended iTunes, you can find all the SRC’s lectures and seminars by going to the iTunes store, going to podcasts, and searching for Stockholm Resilience Centre in the top right corner of iTunes.

Building Resilience in Ontario – more than metaphor or arcane concept

A few weeks ago I stumbled upon the Environmental Commissioner of Ontario’s latest annual report entitled “Building Resilience”. This was a pleasant surprise. Off the top, the Commissioner’s report credits Buzz Holling and the ecological origins of resilience and offers the example of forest fire regimes in Northern Ontario and the systems’ inherent capacity for renewal. Further on the report applies resilience thinking to specific issues including biodiversity conservation and implications of a new MNR (Ministry of Natural Resources) biofibre policy to burn forestry “wastes” for fuel:

“Transforming waste to energy and revenue certainly is attractive from a short-term efficiency standpoint. But there are long-term cycles in play too. An appreciation of resilience dynamics would encourage managers to think hard about the long-term ecosystem functions of these “wastes,” including their role as reserve capital, held in store for the next generation. If nutrient-rich branches, needles and leaves are increasingly harvested rather than left on the forest floor to decompose, what will be the consequences for nutrient cycling? What increased stresses may this place on forest soil fertility, on communities of soil micro-organisms and on future forests?”

Inadvertently, the report also amused with its initial introduction of resilience as an “arcane concept that has lurked in the dank halls of ecological academia for almost four decades”. I’d prefer to think of it as a concept that has been simmering. At any rate, resilience thinking appears to be finding a place in Ontario.

The spring issue of Alternatives journal, Canada’s national environmental magazine, echoes the title “Building Resilience” and offers both a “Hardcore Guide to Resilience” and an interview with Buzz Holling. In addition a piece by Andrew McMurry on “The Rhetoric of Resilience” offers some insight from a linguistic perspective on why perhaps the term itself might be resonating so strongly at this particular point in time:

“Resilience answers nicely to the real and rhetorical exigence. To be sure, resilience is in one sense merely the capacity of systems to absorb stress and maintain or even repair themselves. But resilience is also metaphor that embodies a number of characteristics that Aristotle required of all good figures of speech: it is active, primordial, concise and appropriate.

Resilience implies action, as in “building resilience”. To be resilient suggests an inner toughness: the strength, as its etymology tells us, to “jump back” to a previous state. Sustainability, by contrast, suggests a defensive posture: a desire to stay the same, to resist change, without the attractive ability to push back against change and win out. Resilience also connotes a measure of risk, while sustainability suggests that systems are set: they simply need to be cared for and so carried forward. Resilience acknowledges that risk is a constant, and that systems are always in a struggle against dissipation. If the seas are always calm and the weather mild, you don’t need to be resilient. But in this world, you must be resilient to survive.”

Comparing Panarchy and Pace Layering

On the EcoTrust web magazine People and Place Howard Silverman compares Stewart Brand‘s concept of Pace Layering with Panarchy in Panarchy and Pace in the Big Back Loop:

“The back loop is the time of the Long Now,” writes Resilience Alliance founder Buzz Holling. It is a time “when each of us must become aware that he or she is a participant.”

“The trick is to treat the last ten thousand years as if it were last week, and the next ten thousand as if it were next week,” advises Stewart Brand in The Clock of the Long Now. “Such tricks confer advantage.”

Though Brand’s book precedes Holling’s “Complex Worlds” paper, their dialog runs pretty much like that. And the discussion turns on a pair of interrelated metaphors: panarchy and pace layering.

Mapping Metaphors
Holling and colleagues represent a familiar pattern of growth, conservation, release and renewal in the model of the adaptive cycle. A layering of adaptive cycles becomes a panarchy. The panarchy represents evolving interactions across ecological and social scales of time and space from, say, the pine cone to the forest to the forest products company.

Brand’s metaphor is pace layering, “the working structure of a robust and adaptable civilization.” Organized fast to slow, the layers are: fashion, commerce, infrastructure, governance, culture, and nature. With a nod to Holling, Brand writes, “The combination of fast and slow components makes the system resilient.”

What can we learn by mapping pace against panarchy? Picture a stack of adaptive cycles, with frantic fashion at the bottom, and nature’s biophysical processes, broad and slow, at the top. Reaching from each cyclic layer down to the next is an arrow labeled “remember,” for memory is an important influence that slower cycles exert on faster ones. And stretching from each cycle up to the next is the arrow “revolt,” representing the actions that, in the time of the back loop – of release and subsequent renewal – can enact structural shifts in the cycles above.

Thanks to Buzz Holling for the pointer.

Whole Earth Catalog web archive

coevolutiongaiaThe entire 35-year archive of Whole Earth Catalogs, along with its Supplements, and descendant magazines – CoEvolution Quarterly, and Whole Earth are now available on the web.  The Whole Earth Catalog,was published in 1968 by Stewart Brand, it and its related  magazines embodied a certain type of Californian environmental thinking.  A key concept was systems – which included thinking about people,  and computers, as well as ecosystems, and when I read first read issues of the magazine as a teenager in the 1980s it was my first exposure to systems theory.

The full archive is in a difficult to navigate scanned form, which is difficult to link to or search, however some of the later articles are available as text.  However the archive includes lots of interesting stuff.  For example, Dana Meadows famous article on where to intervene in a system there.  Other interesting bits include articles by ecologists such as HT Odum, Paul Ehrlich, and Buzz Holling as well as an issue focused on scenario planning.

Continue reading

Buzz Holling wins 2008 Volvo Environmental Prize

buzz holling photoBuzz Holling, the father of resilience science and the founder of the Resilience Alliance (and contributor to this blog) has won the 2008 Volvo Environment Prize. Congratulations Buzz!

On the Prize website they write the justification for the award:

“The Volvo Environment Foundation takes great pleasure in awarding its 2008 environment prize to Crawford “Buzz” Holling, one of ecology’s great integrative thinkers for his pioneering lifetime work on ecosystem dynamics, transformation and resilience, and adaptive management.

Crawford “Buzz” Holling is one of the most creative and influential ecologists of our times. His integrative thinking has shed new light on the growth, collapse, and regeneration of coupled human-ecological systems. Current discussions and debates over non-linear systems, adaptation and change, thresholds, tipping points, and resilience are all part of his rich legacy of writing. His analyses have ranged boldly across scales of time and space. His 1973 paper on the “resilience of non-linear ecological systems” reshaped profoundly thinking on the dynamics and transformation of ecological systems. His 1978 volume on Adaptive Environmental Assessment and Management remains the classic work on this important subject 30 years later. Not content with new theoretical insights into the stability and change of human-ecological systems, Holling has profoundly critiqued what he describes as “the pathology of natural resource management,” detailing how things go right and wrong in well-intentioned efforts at resource management. His recent work with Lance Gunderson, Panarchy: Understanding Transformation in Human and Natural Systems, is no less than a far-ranging exploration of fundamental principles of resilience thinking. The newly created Stockholm Resilience Center is itself a highly promising venture built on Holling’s legacy.”

Novelty Needed for Sustainable Development – Resilience 2008

conclusions panel resilience 2008

The Stockholm Resilience Centre has released two press releases on the conclusion of Resilience 2008.

The first Novelty thinking key to sustainable development reports on the concluding panel of the conference in which Elinor Ostrom, Sverker Sörlin, Carole Crumley, Line Gordon and Buzz Holling reflected on the conference, lessons from the past and the answers for the future.

Buzz Holling, considered the father of resilience thinking, called for freedom and flexibility in order to generate multilevel change and novelty thinking. This is needed in a time when several crises are emerging, he said.

- This year a cluster of predicted crises have become aware to the public, such as the rise of food prices due to energy market changes and the collapse of the financial market. We see that small instabilities and risks spread to practically all developed countries in the world. However, globalisation also adds a great positive value because the individual or small groups can have an increasingly global effect, Holling said.

Resilience as an continuance of sustainability thinking
Sverker Sörlin and Carole Crumley both argued that we have moved beyond traditional discussions around sustainability and that resilience thinking is increasingly being embraced as an integrated part of sustainable development thinking.

- Resilience thinking will not replace the sustainability discourse, but we can use resilience to develop sustainability further, Sörlin said. He was followed up by Line Gordon who noted that the key approach with resilience thinking is that although we might have solutions for sustainable development, we will face challenges and we must be prepared for surprises.

Continue reading