VI. Earth Life Emergence: Development of Body, Brain, Selves and Societies

7. Dynamic Ecosystems

Storch, David, et al. Scaling Biodiversity. Cambridge, UK: Cambridge University Press, 2007. With co-editors James Brown and Pablo Marquet, about a major project based in the Southwest environs of the Santa Fe Institute to discern endemic features of the distribution, occupancy, rarity, and hierarchical topology of metazoan species. Not yet seen in full, to be reviewed further, an important contribution on how such a nested fractality can help appreciate and conserve precious animal richness.

Sugihara, George and Hao Ye. Cooperative Network Dynamics. Nature. 458/979, 2009. A review of Ugo Bastolla, et al in the same issue on nested ecosystem mutualisms which serve to minimize competition and foster diversity. The same phenomena are then found to benefit vendor-customer relations.

Thus, whereas competition normally limits the number of species that can co exist (as tough competitive markets often tend towards monopoly), the nested cooperative models studied here reduce competition and allow the system to support more species, or higher biodiversity. (979) Nestedness is not an isolated property of plant–animal communities, however, but appears in various social contexts, including the organization of the New York garment industry4 and as disassortativity in the topology of the Fedwire network. Indeed, it is possible that the appearance of similar topology among diverse cooperative networks may be a result of simple shared assembly rules. (979)

Suweis, Samir, et al. Emergence of Structural and Dynamical Properties of Ecological Mutualistic Networks. Nature. 500/449, 2013. We post this paper by Samir Suweis and Amor Maritan, University of Padova, with Filippo Simini, Northeastern University, and Jayanth Banavar, University of Maryland, as an example among many of how the presence of such equally real interconnections between all the pieces and components from biochemicals to neurons and creatures. In regard, this shift and advance is engendering a much expanded understanding of proactive living systems. Of further notice, as this paper exhibits, is the finding that the same dynamic topologies universally characterize and repeat at every strata and instance from genomes to brains and species. See also “Networks: Exapnding Evolutionary Thinking” by Eric Bapteste, et al in Trends in Genetics (29/8, 2013) which evokes this quiet revolution.

Mutualistic networks are formed when the interactions between two classes of species are mutually beneficial. They are important examples of cooperation shaped by evolution. Mutualism between animals and plants plays a key role in the organization of ecological communities. Such networks in ecology have generically evolved a nested architecture independent of species composition and latitude. Here we show that nested interaction networks could emerge as a consequence of an optimization principle aimed at maximizing the species abundance in mutualistic communities. Using analytical and numerical approaches, we show that because of the mutualistic interactions, an increase in abundance of a given species results in a corresponding increase in the total number of individuals in the community, as also the nestedness of the interaction matrix. Our work provides a unifying framework for studying the emergent structural and dynamical properties of ecological mutualistic networks. (Abstract excerpts)

Tarnita, Corina, et al. A Theoretical Foundation for Multi-Scale Regular Vegetation Patterns. Nature. 541/398, 2017. Princeton University, University of Strathclyde, Hebrew University of Jerusalem, and University of Idaho systems botanists describe a sophisticated, multi-media confirmation of intrinsic self-organized patterns and dynamics. The many studies that this Ecosystem section has reported on since the early 2000s do indeed seem to be untangling and confirming nature’s universal scale. See also Spatial Self-Organization of Ecosystems by Robert Pringle and Corina Tarnita in the Annual Review of Entomology (62/359, 2017).

Self-organized regular vegetation patterns are widespread and thought to mediate ecosystem functions such as productivity and robustness, but the mechanisms underlying their origin and maintenance remain disputed. Two competing hypotheses are currently debated. On the one hand, models of scale-dependent feedbacks, whereby plants facilitate neighbours while competing with distant individuals, can reproduce various regular patterns identified in satellite imagery. Owing to deep theoretical roots and apparent generality, scale-dependent feedbacks are widely viewed as a unifying and near-universal principle of regular-pattern formation despite scant empirical evidence. On the other hand, many overdispersed vegetation patterns worldwide have been attributed to subterranean ecosystem engineers such as termites, ants, and rodents.

Here we provide a general theoretical foundation for self-organization of social-insect colonies, validated using data from four continents, which demonstrates that intraspecific competition between territorial animals can generate the large-scale hexagonal regularity of these patterns. Using Namib Desert fairy circles as a case study, we present field data showing that these landscapes exhibit multi-scale patterning. These patterns and other emergent properties, such as enhanced resistance to and recovery from drought, instead arise from dynamic interactions in our theoretical framework, which couples both mechanisms. The potentially global extent of animal-induced regularity in vegetation—which can modulate other patterning processes in functionally important ways—emphasizes the need to integrate multiple mechanisms of ecological self-organization. (Abstract)

Thompson, John. Mutualistic Webs of Species. Science. 312/372, 2006. A review of a research article by Jordi Bascompte, et al in the same issue on the self-organization of asymmetric coevolutionary networks in nested nature.

Complex mutualistic webs are therefore not haphazard collections of specialists and generalists. Evolution and coevolution appear to shape these multispecific interactions in a predictable manner regardless of the exact composition of species or ecosystem,… (372)

Touboul, Jonathan, et al. On The Complex Dynamics of Savanna Landscapes. Proceedings of the National Academy of Sciences. Online January 29, 2018. Brandeis, Yale (Ann Staver), and Princeton University (Simon Levin) researchers offer further quantifications of intrinsic ordering principles which underlie and sustain nature’s seemingly tangled flora and fauna.

This paper makes a significant contribution both to ecological theory and to an understanding more generally regarding how complex dynamics can emerge in mathematical models from quite simple underlying assumptions. Empirical and theoretical work has suggested that savanna–forest systems exhibit bistability, potentially flipping from one state to another in the face of environmental change. Here, we show that the dynamics of those systems may be much more complicated and present surprising responses to environmental variability. From a mathematical point of view, the models that we explore exhibit a rich array of behaviors and responses to random perturbations, and we suggest that such dynamics may arise in a variety of contexts.

Tu, Chengyi, et al. Reconciling Cooperation, Biodiversity and Stability in Complex Ecological Communities. Nature Scientific Reports. 9/5580, 2019. With an opening nod to Alfred Lotka and Vito Volterra from the early 1900s, Chengyi Tu, UC Berkeley, Samir Suweis, Marco Formentin, and Amos Maritan, University of Padova, and Jacopo Grilli, International Centre for Theoretical Physics, Trieste (search names) continue to finesse mathematical theories which are well exemplified by active creaturely groupings. It is again averred that cooperative relations are most important for achieving viable success.

Turner, Monica, et al. Landscape Ecology in Theory and Practice. New York: Springer, 2001. A new textbook that emphasizes the conception of ecosystems as self-organized, fractally scaled dynamic networks, which illustrates how this paradigm has gained acceptance.

van de Koppel, Johan, et al. Experimental Evidence for Spatial Self-Organization and Its Emergent Effects in Mussel Bed Ecosystems. Science. 322/739, 2008. Ecologists from the Netherlands, Wales, and France offer as confirmation to the theoretical work of Simon Levin in Fragile Dominion and in Ricard Sole and Jorge Bascompte’s Self-Organization in Complex Ecosystems this detailed case study of mussel bed geometries in the tidal flats of the Menai Strait near Bangor, UK.

Spatial self-organization is the main theoretical explanation for the global occurrence of regular or otherwise coherent spatial patterns in ecosystems. Using mussel beds as a model ecosystem, we provide an experimental demonstration of spatial self-organization. (739)

vandermeer, John and Ivette Perfecto. Ecological Complexity and Agroecology. London: Routledge, 2017. University of Michigan senior professors of ecology, evolutionary biology, natural resources and environments (search) provide a unique textbook for this subject which can also represent a 2010s revolutionary, advantageous synthesis of this vital sustenance resource with nature’s innate underlay of self-organizing network patterns and processes. Chapter titles such as Multidimensionality, Coupled Oscillatory, Stochasticity and Critical Transitions discuss and apply the latest ecosmos code mathematical guidance. OK

While 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 notions of how ecological systems function. In this context, the new science of complexity has become vitally important in the modern science of ecology. 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.

Vandermeer, John and Senay Yitbarek. Self-Organized Spatial Pattern Determines Biodiversity in Spatial Competition. Journal of Theoretical Biology. 300/48, 2011. By way of sophisticated complexity mathematics, University of Michigan bioecologists confirm a natural balance but in an actual case of a “competitive coexistence” that serves both creature and colony. These endemic “competitive relationships” then generate previously unrecognized spatial mosaics that serve to maintain ecosystem viability.

In a simple cellular automata model it is shown that self-organization of spatial pattern in a community of strong competitors may generate a previously unrecognized mechanism of species richness determination. Employing some well-known general properties of interspecific competition, we elaborate a theoretical framework that generates both spatial mosaics and spiral waves within the same conceptual framework, dependent on the covariance of competition. We demonstrate that the qualitative nature of the spatial pattern depends on the “balance” of competition and that the number of species retained in the community depends on this spatial patterning. (Abstract, 48)

We examine the process of self-organization of spatial pattern in a community of strong competitors and show how the details of the self-organizing process generate a previously unrecognized mechanism of species richness determination. (48) The existence of spatial pattern in biological communities is familiar. Many organisms, especially sessile forms, exist in dramatic nonrandom patterns, a phenomenon well-known to early naturalists. (48)

Vandermeer, John, et al. New Forms of Structure in Ecosystems Revealed with the Kuramoto Model. Royal Society Open Science. February, 2021. University of Michigan sustainability enviromentalists including Ivette Perfecto post a latest advance of their project to better understand diverse flora and fauna biotas by way of nonlinear network complexities. (Also at arXiv:2006.16006) It opens with a review of prior glimpses of a natural, endemic nonlinearity in formative effect. Into the 2010s, global computational and communicative efforts are now well able to quantify independent, mathematical, complex adaptive self-organizations. This paper then cites a new perception that ecosystems are composed of periodic, interactive, synchronized oscillations between transitional phases such as predator/prey, invasion/resistance and so on. Thus, even myriad ecologies are found to be defined by a “chimera” condition, similar to other reams such as brains and metabolisms.

For a series of related work, see Viewing Communities as Coupled Oscillators: Elementary Forms from Lotka and Volterra to Kuramoto by Zachary Haijan-Forooshani and John Vandermeer in bioRxiv (May 27, 2020), The Community Ecology of Herbivore Regulation in an Agroecosystem: Lessons from Complex Systems by John Vandermeer et al in BioScience (69/12, 2019, reviewed herein), Chimera Patterns Induced by Distance-Dependent Power-Law Coupling in Ecological Networks by Tanmoy Banerjee, et al in Physical Review E (94/032206, 2016) and Synchronization Unveils the Organization of Ecological Networks with Positive and Negative Interactions by Andrea, Giron, et al in Chaos (26/065302, 2016). A unique text for this ecosmic ecosystem revolution is Ecological Complexity and Agroecology by John Vandermeer and Ivette Perfecto (Routledge, 2017, search).

Ecological systems, as is often noted, are complex. Equally notable is the common generalization that complex systems tend to be oscillatory, which could provide insights into the structure of ecological systems. A popular analytical tools for such studies is the Kuramoto model of coupled oscillators. Using a well-studied system of pests and their enemies in an agroecosystem, we apply this stylized model to ask whether its actual natural history is reflected in the dynamics of the qualitatively instantiated Kuramoto model. Indeed, synchrony groups with an overlying chimeric structure, depending on the strength of the inter-oscillator coupling, are found. We conclude that the Kuramoto model presents a novel window to better understand the interactive forms of ecological systems. (Abstract)

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