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V. Life's Corporeal Evolution Develops, Encodes and Organizes Itself: An Earthtwinian Genesis Synthesis

6. Dynamic Fractal Network Ecosystems

Harte, John and Erica Newman. Maximum Information Entropy: A Foundation for Ecological Theory. Trends in Ecology and Evolution. 29/7, 2014. UC Berkeley environmentalists finesse thermodynamic effects by way of probability distributions so as to achieve a better, more optimum, analysis of dynamic ecosystems. A later paper with Andrew Rominger is Metabolic Partitioning Across Individuals in Ecological Communities in Global Ecology and Biogeography (Online July 2017).

The maximum information entropy (MaxEnt) principle is a successful method of statistical inference that has recently been applied to ecology. Here, we show how MaxEnt can accurately predict patterns such as species–area relationships (SARs) and abundance distributions in macroecology and be a foundation for ecological theory. We discuss the conceptual foundation of the principle, why it often produces accurate predictions of probability distributions in science despite not incorporating explicit mechanisms, and how mismatches between predictions and data can shed light on driving mechanisms in ecology. We also review possible future extensions of the maximum entropy theory of ecology (METE), a potentially important foundation for future developments in ecological theory. (Abstract)

Harte, John, et al. Metabolic Partitioning Across Individuals in Ecological Communities. Global Ecology and Biogeography. Online July, 2017. Environmentalists Harte, and Andrew Rominger, UC Berkeley, and Erica Newman, University of Arizona, continue to effectively apply maximum entropy principles across real ecosystems. See Harte & Newman 2014 for more theory.

The mechanistic origin and shape of body-size distributions within communities are of considerable interest in ecology. A recently proposed light-limitation model provides a good fit to the distribution of tree sizes in a tropical forest plot. The maximum entropy theory of ecology (METE) also predicts size distributions, but without explicit mechanistic assumptions, and thus its predictions should hold in ecosystems generally, regardless of whether they are light limited. A comparison of the form and success of the predictions of the model and the theory can provide insight into the role that mechanisms play in shaping patterns in macroecology. The prediction by the METE of the size distribution of organisms is remarkably similar in form to that of the model: power-law behaviour in the size range where the light-limitation model predicts a power law, and exponential behaviour in the size range where the model predicts an exponential tail. (Abstract)

Harte, John, et al. Self-Similarity in the Distribution and Abundance of Species. Science. 284/334, 1999. The article discusses how species are distributed by a nested webwork in biome habitats, an arrangement which reflects the utility of fractal geometry to describe natural systems.

We have demonstrated that self-similarity theory provides an overarching framework within which empirically supported patterns in ecology are unified, new and plausible results are derived, and the connection between the SAR (species-area relationship) and the lognormal abundance distribution is questioned. (336)

Hatton, Ian, et al. The Predator-Prey Power Law: Biomass Scaling Across Terrestrial and Aquatic Biomes. Science. 349/1070, 2015. When we first posted this section in 2004, evidence for common principles was as patchy as many ecosystems. By 2017 however, McGill University, University of Guelph, Perimeter Institute (Matteo Smerlak), Tanzania Wildlife Research Institute, and Centre for Biodiversity Theory and Modeling, CNRS, France researchers can quantify a universality of patterns and process which appear independently of local environs. See also a commentary Energy Flows in Ecosystems by Just Cebrian in the same issue.

Ecosystems exhibit surprising regularities in structure and function across terrestrial and aquatic biomes worldwide. We assembled a global data set for 2260 communities of large mammals, invertebrates, plants, and plankton. We find that predator and prey biomass follow a general scaling law with exponents consistently near ¾. This pervasive pattern implies that the structure of the biomass pyramid becomes increasingly bottom-heavy at higher biomass. Similar exponents are obtained for community production-biomass relations, suggesting conserved links between ecosystem structure and function. These exponents are similar to many body mass allometries, and yet ecosystem scaling emerges independently from individual-level scaling, which is not fully understood. These patterns suggest a greater degree of ecosystem-level organization than previously recognized and a more predictive approach to ecological theory. (Abstract)

Coarsening refers to any relaxation process wherein the characteristic length scale grows over time. Examples of coarsening phenomena abound in condensed matter physics: domain growth in quenched magnets; Ostwald ripening in alloys and emulsions; bubble coalescence in soap froths; phase separation in binary mixtures; etc. In these systems, excess free energy is stored in localized defects whose size spontaneously increases over time so as to reduce their density and hence the total free energy. The relevance of coarsening phenomena extends to astrophysics, with galactic clustering, socio-dynamics, e.g. in simplified models of consensus formation or of racial segregation, and in many other branches of sciences. Key universal features of coarsening are dynamic scaling and asymptotic self-similarity. (2)
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A general scaling law for ecology Despite the huge diversity of ecological communities, they can have unexpected patterns in common. Hatton et al. describe a general scaling law that relates total predator and prey biomass in terrestrial and aquatic animal communities (see the Perspective by Cebrian). They draw on data from many thousands of population counts of animal communities ranging from plankton to large mammals, across a wide range of biomes. They find a ubiquitous pattern of biomass scaling, which may suggest an underlying organization in ecosystems. It seems that communities follow systematic changes in structure and dynamics across environmental gradients. (Science Editor)

Hatton et al show that this pattern – that is, a decreasing predator to prey biomass ratio with increasing prey biomass – applies universally in both aquatic and terrestrial ecosystems. Furthermore, they demonstrate that this universal pattern emerges from a sublinear scaling that is independent of the ecosystem considered. (Cebrian 1053)

Higgins, Paul, et al. Dynamics of Climate and Ecosystem Coupling. Philosophical Transactions of the Royal Society of London B. 357/647, 2002. The paper argues that no biotic phenomena can be studied in isolation from its environment.

Interactions between subunits of the global climate-biosphere system (e.g., atmosphere, ocean, biosphere and cryosphere) often lead to behavior that is not evident when each subunit is viewed in isolation. This newly evident behavior is an emergent property of the coupled subsystems. (647)

Ho, Mae-Wan and Robert Ulanowicz. Sustainable Systems as Organisms? BioSystems. 82/1, 2005. A biophysicist and an ecologist, who have each contributed to a “thermodynamics of organized complexity,” propose that sustainable ecosystems are best seen as organisms because they express similar attributes of energy flow and storage, dynamic cycles, a nested hierarchy, and so on. As a consequence, this viable state ought to be a goal for our communities and economies.

Holling, C. S. Understanding the Complexity of Economic, Ecological, and Social Systems. Ecosystems. 4/5, 2001. The University of Florida ecologist theorizes how complex adaptive systems appear to be in self-organizing effect across every natural and human domain. Their presence is dubbed a “Panarchy” as a way to combine scalar features with the dynamic interplay between change and persistence as embodied by the Greek god Pan. The review article is based on a concurrent book Panarchy: Understanding Transformations in Human and Natural Systems. by Lance Gunderson and Holling (Island Press, 2001). In 2020 regard, as the paper by Jose Ibarra, et al herein attests, this prescient notice of common CAS networks which suffuse and untangle all phases of flora and fauna is now well verified and put into practice.

Hierarchies and adaptive cycles comprise the basis of ecosystems and social-ecological systems across scales. Together they form a panarchy. The panarchy describes how a healthy system can invent and experiment, benefiting from inventions that create opportunity while being kept safe from those that destabilize because of their nature or excessive exuberance. The whole panarchy is therefore both creative and conserving. An analysis of this process helps to clarify the meaning of “sustainable development.” Sustainability is the capacity to create, test, and maintain adaptive capability. Development is the process of creating, testing, and maintaining opportunity. (Abstract excerpt)

Panarchy is the hierarchical structure in which systems of nature (forests, grasslands, lakes, rivers, and seas), and humans (structures of governance, settlements, and cultures), as well as combined human-nature systems and social-ecological systems…are interlinked in never-ending adaptive cycles of growth, accumulation, restructuring, and renewal. These transformational cycles take place in nested sets at scales ranging from a leaf to the biosphere over periods from days to geologic epochs, and from scales of a family to a sociopolitical region over periods from days to centuries. (392)

Holyoak, Marcel, et al, eds. Metacommunities: Spatial Dynamics and Ecological Communities. Chicago: University of Chicago Press, 2005. An exploration of this conception of intricately interlinked ecosystems. Expanding on the work of Simon Levin, a paper by Mathew Leibold, et al views them as complex adaptive systems.

Ibarra, Jose, et al. Nurturing Resilient Forest Biodiversity: Nest Webs as Complex Adaptive Systems. Ecology and Society. 5/2, 2020. This contribution by seven ecologists with postings in Chile, Canada, Argentina, Rwanda, and Ecuador including Suzanne Simard could well be seen from our Earthwise vista as an exemplary 21st century fulfillment of a natural genesis ecosmos. From circa 2000 inklings (SFI, John Holland, C. S, Holling (Panarchy), Simon Levin) to these 2020s, the wide and deep discovery of a universal self-organizing process via many diverse, interactive entities is now robustly evident. As the Abstract notes, this entry describes its presence across diverse scales of flora and fauna ecosystems. And as the whole website reports, a similar, iconic occasion has likewise been found from galactic clusters and quantum networks to life’s origin, as evolutionary gestation, anatomic metabolism, neural cognition, animal groupings and onto our global sapiensphere.

Forests are complex adaptive systems in which properties at higher levels emerge from localized networks of many entities interacting at lower levels, allowing the development of multiple ecological pathways and processes. Cavity-nesters exist within networks known as “nest webs” that link trees, excavators, (woodpeckers), and nonexcavators (many songbirds, ducks, raptors) at the community level. We use the idea of panarchy (interacting adaptive cycles at multiple spatio-temporal scales) to expand the nest web concept to levels from single tree to whole biome. We then assess properties of nest web systems (redundancy, heterogeneity, memory, nonlinearity) from our studies in temperate, subtropical, and tropical forests across the Americas. Although nest webs from Chile, Canada, Argentina, and Ecuador have independent regimes, they share these main features of complex adaptive systems. (Abstract excerpt)

Jorgensen, Sven and Felix Muller, eds. Handbook of Ecosystems Theories and Management. Boca Raton, FL: Lewis Publishers, 2000. A reference work about the paradigm shift in ecology from a view of nature in balance to one of complex open systems in a far-from-equilibrium state. Authors consider various aspects such as self-organization, information, thermodynamics, hierarchies and criticality.

Jorgensen, Sven, editor-in-chief. Encyclopedia of Ecology. Amsterdam: Elsevier, 2008. A five volume, 5000 page compendium that covers in depth and insight this vital earthscape subject. Over 500 authorities from around the world, such as David Orr (Ecological Systems), Victoria Dawson (Ecofeminism), Robert Ulanowicz (Autocatalysis), Elinor Ostrom (Tragedy of Commons), and Penelope Boston (Gaia), weigh in on every theoretical and practical aspect. As the editor cites next, the endeavor is meant to convey an essential interconnectedness of all life from microbes to a metropolis, each and all within a viable biosphere. In this regard, several Russian scientists and others turn to philosophical guidance from the thought and writings of the geochemist Vladimir Vernadsky (1863 – 1945). As a result, the project imbues a phenomenal cosmos whose “living matter” evolves and emerges by innate, self-organizing propensities through geological, biological, and cognitive knowledge spheres. Ideally then, such a natural environmental wisdom ought to be applied in a respectful way to transform consumptive civilizations to a more viable and sustainable ecosphere.

The encyclopedia is based on a broad and inclusive view of ecology with an emphasis on holistic perspectives. Holism arises because organisms are irreducible from each other and their environments. Therefore, tone and tendency in ecology is toward the holistic range along the continuum of holism-reductionism in science. We can observe and study trees, but we must never forget that the trees are components with the forest system. Ecology deals with the structure and functioning of nature as a system. (3, Sven Jorgenson)

Jorgensen, Sven, et al. A New Ecology: Systems Perspective. Amsterdam: Elsevier, 2007. Nine ecologists, namely the lead author, Simone Bastianoni, Brian Fath, Felix Muller, Joao Marques, Soren Nielsen, Bernard Patten, Enzo Tiezzi, and Robert Ulanowicz, strive to gather, synthesize, and articulate via nonlinear thermodynamics and complexity science such theoretical ecosystem properties as openness, connectivity, hierarchy, dynamic life cycles, and robustness.

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