Ecological Complexity and Agroecology

John Vandermeer, Ivette Perfecto

• Publisher: Routledge
• Year: 2017
• ISBN:
  9781315313672
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Ecology
• Index: Biological Sciences

This text reflects the immense current growth in interest in agroecology and changing approaches to it. While it is acknowledged that the science of ecology should be the basis of agroecological planning, many analysts have out-of-date ideas about contemporary ecology. Ecology has come a long way since the old days of "the balance of nature" and other romantic notions of how ecological systems function. In this context, the new science of complexity has become extremely important in the modern science of ecology. The problem is that it tends to be too mathematical and technical and thus off-putting for the average student of agroecology, especially those new to the subject. Therefore this book seeks to present ideas about ecological complexity with a minimum of formal mathematics.

The book's organization consists of an introductory chapter, and a second chapter providing some of the background to basic ecological topics as they are relevant to agroecosystrems (e.g., soil biology and pest control). The core of the book consists of seven chapters on key intersecting themes of ecological complexity, including issues such as spatial patterns, network theory and tipping points, illustrated by examples from agroecology and agricultural systems from around the world.

1
Introduction

A new enthusiasm grips agriculture today. Across the globe old and young farmers are moving toward rethinking the foundations, rejecting the old triumphalist story of “industrial agriculture” to embrace the idea that the science of ecology should be at the foundation of agriculture, much as it has been in more traditional forms of agriculture in the past and present.¹ It is an enthusiasm, transforming to a revolution, born from a careful and critical analysis of the flawed story of how the industrial revolution came to agriculture to provide the world with ever-increasing productivity based on sophisticated technology – generating a gigantic cornucopia of enormous quantities of food. The ugly underbelly of this behemoth has become too difficult to ignore, with cancer epidemics produced from its pesticides, ocean dead zones fueled by its fertilizers, and farmers representing generations of tradition expelled from their land and even their culture. Yet the modern industrial agricultural system seems incapable of facing up to the cul-de-sac it has created for itself, producing hunger and obesity simultaneously, degrading soils, creating dead zones in the oceans, and knowingly promoting technologies that worship short-term gain over long-term sustainability. It is thus not surprising that a revolution would emerge.

Resisting the narrative of the glorious victory over nature, this movement to divest from the industrial agricultural system has been waiting in the wings at least since the nineteenth century, patiently accumulating sustenance from experience and analysis.² And its location is not in the centers of political and economic power, but rather in regions where traditional knowledge (frequently connected to popular social movements) intersects with the natural world.³ Emerging as practice at the level of the farm, to some extent refusing modern scientific accoutrements, this new revolution has one central theoretical tenet that runs throughout: the fundamental rules of natural systems should be guidelines for planning and management. Or, equivalently, the science of ecology should be foundational, the key observation that motivates this book. And what precisely is that science?

Ecology is not an old and venerated discipline. Even though Darwin himself wrote brilliantly about it, he did not even recognize it as a thing. Ernst Haeckel is credited with inventing the word,⁴ but certain key concepts emerged only in the twentieth century, which makes it little more than a century old. Yet that century provided key observations, experiments and theories that today are regarded as much a scientific core as Newton’s theory of gravity is for physics. Especially in the past three decades, modern ideas have been brought to the table and what had been moving in a purely “ivory tower” direction suddenly appears poised to merge with more traditional ideas. One of those modern ideas is “complexity,” and an ecological system is increasingly recognized as a “complex system.” Originally from the Greek com, meaning together, and plex, meaning woven, a complex system is characterized by its “interwovenness.”

Although complexity (and complex systems) is generally regarded as avant garde in academia,⁵ we find that it is not a foreign concept to most traditional farmers we have encountered. Indeed our experiences include poor farmers in Latin America explaining elements of how their farm works in ways that, with only a change in some of the particular words used, could be mistaken for the introductory paragraph of a textbook of complex systems. They speak of, for example, chaos in product pricing, although their lexicon does not admit the word chaos. They understand that predators and their prey interlock such that long-term oscillations may emerge, although they would not call those coupled oscillators. They know that fixing the exact time for planting requires them to make environmental observations that have important unpredictable components, but we have never heard a farmer say “stochasticity.” In the historical junction at which we seem to be poised, we argue that the time is ripe to take a burgeoning interdisciplinary movement within academia, complexity science, and combine it with various traditional forms of knowledge to construct a unique paradigm to undergird the burgeoning movement called agroecology.

In sum, the past quarter century has seen the field of ecology become enriched with ideas borrowed from complexity science, generating a new kind of ecology, increasingly referred to as “ecological complexity.” Exploring the intersection of this new ecology with insights from traditional systems, in service of understanding the agroecosystem, is the fundamental subject of this book.

The idea of ecological complexity

It is not likely to be controversial to suggest that ecological systems can be very complicated. A useful example we have been using in teaching for years is the cod fishery in Newfoundland. In the early 1990s the fishery collapsed, leading to an energetic search for culpability. And some of the Canadian popular press hyped the idea that seals, known predators of codfish, were at fault, effectively taking a simplified view of the ecosystem as “seals eat codfish,” nothing more to say. Canadian environmentalist David Lavigne looked more carefully at the system and concluded that the situation is a bit more complicated, to say the least. His graph, now widely cited when reporting on the amazing entanglement of ecological systems, is reproduced here in Figure 1.1.

Yet the largely correct observation that ecological systems are complicated is really quite different from the claim that they are complex, at least in the modern usage of those terms, especially as we use them in this book – complicated does

Figure 1.1 David Lavigne’s partial food web with codfish as the central player

Compiled from a variety of sources by D. Huyck and reprinted from Lavigne (2003).

not equal complex. A complicated system is a system with many components; by understanding each component you can understand the whole. In contrast, as mentioned before, a complex system is characterized by interdependencies and it is the relationships among the parts that give rise to the whole. Understanding each component does not necessarily lead to an understanding of the whole. Complex systems have, in recent years, taken on a meaning that is more sophisticated and subtle than in the past. Examples of what current “complexity” scientists regard as complex systems range widely, with applications in disciplines ranging from physics and chemistry to sociology and economics, to neurobiology and behavior and, of course, ecology.⁶ But the statement that a system is complex means more today than simply that it has many components (i.e., that it is complicated).

A general flavor of the idea can be appreciated with a key contradiction. It is certainly common sense to think that a large number of things interacting with one another will give rise to a pattern or a behavior that is itself quite complicated, and this seems to be generally true. It is likewise common sense to think that a very small number of things interacting with simple rules will give rise to a pattern or a behavior that is itself quite simple, and this too seems to be generally true. Imagining a 5-year-old child drawing at her desk evokes relatively simple images of behavior, while imagining a classroom of twenty 5-year-old children interacting with one another evokes relatively complicated images of behavior. Yet this sensible description of the world can be surprisingly contradicted by systems that are truly complex. To take a classic pair of ideas, when systems are truly complex it is sometimes the case that (1) apparently simple systems can exhibit very complicated behavior and (2) apparently complicated systems can exhibit very simple behavior. Frequently complex systems, as viewed through a contemporary lens, take on one or another of these forms, sometimes appearing to incorporate both at the same time. The seemingly straightforward correlation between complicated structure and complicated patterns or behavior is in contradiction with the actual potentialities of complex systems to generate unexpected and unusual patterns and behavior.

Consider, for example, the whirling and ever-changing patterns of flying star-lings in their famous murmurations (a beautiful example can be seen, as of this writing, at: www.youtube.com/watch?v=eakKfY5aHmY), an image of which we reproduce in Figure 1.2a. Such spectacular moving patterns formed by these birds can be explained by nothing more than individual starlings simultaneously trying to locate themselves at the center of the group of individuals surrounding them and trying to stop anyone near them from getting too close. Thus, a spectacularly complicated pattern emerges from two very simple rules.

At the other extreme, ecological communities are normally very complicated (recall Figure 1.1), and spatially distributed in a non-random fashion. Multiple interactions occur among species; extinctions of species happen regularly; new species arrive from afar; predation, competition, mutualism and many other forces are operative. Yet that complexity can yield a remarkably simple pattern. A classic example is the structure of species diversity on islands (Figure 1.2b).

Figure 1.2 Examples of complex systems. Above: Starling murmurations, an example of a system with very simple rules producing complicated behavioral patterns. Below: The species diversity/island size relationship, caused by very complicated patterns of reptile and amphibian species interactions on and among islands in the Caribbean, yet forming a regular and predictable relationship between species diversity and island size.⁷

Source: (a) Walter Baxter: https://commons.wikimedia.org/wiki/File:Starling_murmuration.webp (b) Denis M: https://en.wikipedia.org/wiki/File:Area_species_curve_herpetofauna.svg.

Multiple species interact with one another as competitors, predators, behavior alterers and more, with population-level processes such as extinction and migration imposed on top of such a complicated system, yet a very regular linear pattern emerges when the log of the number of species is plotted against the log of the size of island. A regular and simple pattern emerges from extremely complicated rules.

As is evident from the previous examples, a central feature of complex systems is that you cannot understand the system as a whole by breaking it down into smaller parts and studying those parts in isolation. Although any scientific endeavor must simplify a system in order to study it, the system itself cannot be simplified – it takes on its characteristics from the interactions of its components. We cannot describe it any better than Levins and Lewontin already described it in their classic The Dialectical Biologist:

It is not that the whole is more than the sum of its parts. But that the parts acquire new properties. But as the parts acquire properties by being together, they impart to the whole new properties, which are reflected in changes in the parts, and so on. Parts and wholes evolve in consequence of their relationship, and the relationship itself evolves. These are the properties of things we call dialectical: that one thing cannot exist without the other, that one acquires its properties from its relation to the other, that the properties of both evolve as a consequence of their interpenetration.⁸

Twenty years later, political scientists Miller and Page place the same issues within the paradigm of the “new” science of complex systems:

If parts are really independent from one another, then even when we aggregate them we should be able to predict and understand such “complicated” systems. As the parts begin to connect with one another and interact more, however, the scientific underpinnings of this approach begin to fail, and we move from the realm of complication to complexity, and reduction no longer gives us insight into construction.⁹

It is this vision of complexity that we hope to bring to the theory and practice of agroecology. Although remaining in the shadows of the industrial agricultural system that dominates most agricultural land in the world, it is striking, in some regions, how rapid is the growth of agroecological farms, even if not specifically called “agroecological,” and despite the fact that the actual land surface they occupy remains small.¹⁰ However, it is the spirit that these farmers bring with them that is the most striking. Millions of farming families are actually working the land, caring for the land, and in many cases taking on the mantra of being involved in something new, something perhaps revolutionary. This newness derives in part from a negation of the large-scale industrial monocultures, from a realization that alternative forms of production must, as soon as possible, replace the wasteful and environmentally poisonous system that emerged from the industrial agricultural model. These ideas, like all ideas, originate neither in a political nor historical vacuum. The intersection of ideas from multiple actors, acting across generations, is what gives this new movement its strength. We begin here by acknowledging a few of these actors so as to recognize at least some of the giants on whose shoulders we sit.

Early revolutionaries in the new agriculture

George Washington Carver is one of the most underappreciated figures in the history of US agriculture. He was a scientist, an educator and a social activist.¹¹ He started his life as a slave, yet climbed the ladder of academic success, securing a faculty position at the Tuskegee Institute in Alabama. He was dedicated to the education of the next generation of African American students and, most importantly, established a system of bringing science to the people with his mobile demonstration laboratories (so-called Jessup wagons). It was only through him that poor black farmers were able to gain access to scientific information about agriculture. He set the stage for the transfer of scientific information, including the latest scientific discoveries, to the poorest of the poor in the United States.

While Carver brought science to the farmers, Gabrielle Matthaei and Albert Howard learned from the farmers and brought their deep multigenerational knowledge to scientists.¹² These two British botanists, married in 1905 and intimately involved in each other’s research, were dispatched to Britain’s various colonies to teach “the backward farmers of the colonies” about the newest advances in agriculture honed in the agricultural experiment stations of the British Empire. But when they got to India, they realized that the Indian farmers had agricultural techniques that were superior in many ways to the agricultural techniques developed...