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

7. Dynamic Ecosystems

Brown, James, et al. Toward a Metabolic Theory of Ecology. Ecology. 85/7, 2004. A 51 page section contains this MacArthur award lecture and peer commentaries as a prolegomena to a unified theory of organisms within their natural environment. In this context, energetics, bodily mass, and other somatic properties appear to define a consistent metabolic scale from microbes to whales.

MTE (Metabolic Theory of Ecology) suggests that underlying the diversity of living things and the complexity of ecological systems are fundamental unities, some of which reflect how first principles of biology, physics, and chemistry govern the fluxes and pools of energy and materials within organisms and between organisms and their environments. (1821)

Cavagna, Andrea and Irene Giardina. Bird Flocks as Condensed Matter Systems. Annual Review of Condensed Matter Physics. Vol. 5, 2014. Noted more in Active Matter, University of Rome La Sapienza physicists contend that these dynamic behaviors are amenable to study and understanding by way of these traditional physical theories.

Chown, S. L., et al. Macrophysiology: Large-scale Patterns in Physiological Traits and their Ecological Implications. Functional Ecology. 18/2, 2004. An introduction to a topical issue on “physiological ecology.” This aspect has lately gained theoretical roots in physics and chemistry by which uncover universal principles and topologies throughout flora and fauna. Typical articles are on how metabolism varies with temperature and the presence of a ubiquitous quarter-power scaling rule.

Chuang, John, et al. Homeorhesis and Ecological Succession Quantified in Synthetic Microbial Ecosystems. Proceedings of the National Academy of Sciences. 116/14852, 2019. Rockefeller University, NYC systems biologists provide a unique way to identify the presence of reliable mathematic patterns which underlie and shape seemingly contingent environmental changes. Bacteria colonies in a laboratory are found to be representative model of actual field phenomena, which also implies that the nonlinear forces are at invariant effect for any creaturely activities.

Many ecological processes are largely stochastic in nature. Nevertheless, the dynamics occurring in ecosystems following a major change, such as regrowth of a forest after a fire, often follow regular temporal patterns, a condition called ecological succession. We observed similar succession in simple microbial communities consisting of algae and ciliates colonizing a new environment and studied it by measuring many replicates over several days. Abundances, which were initially highly variable across replicates, rapidly converged to similar trajectories, a phenomenon called homeorhesis. (Significance)

Collier, John and Graeme Cumming. A Dynamical Approach to Ecosystem Identity. Brown, Bryson, et al, eds. Philosophy of Ecology. Amsterdam: Elsevier, 2012. A University of Kwazulu-Natal, RSA, complexity philosopher and a University of Cape Town ornithologist sketch out how environmental biotas might be considered to possess their own self-sustaining “individuation.” Such an appreciation can then help inform a respectful maintenance of its flora and fauna. See also Collier’s paper “Holism and Emergence” in the South African Journal of Philosophy, (30/2, 2011).

Despite their diversity, complex adaptive systems are considered to have a number of common properties. They are assembled from diverse components that interact with one another. Complexity evidences itself through system dynamics, which include non-linear relationships between key variables, the presence of local equilibria and thresholds, feedback loops, and the ability to self-organize, learn, and respond actively to environmental change. (201)

Ecosystems are a particular kind of complex adaptive system. They are commonly understood to consist of organisms, an abiotic environment, and a set of interactions that occur between organisms and between organisms and between organisms and their environment. Although we focus here on ecosystems, many of the same ideas are more generally relevant to other complex adaptive systems. (201-202)

Cumming, Graeme. Spatial Resilience in Social-Ecological Systems. Berlin: Springer, 2011. A coauthor with Jon Norberg of the 2008 Complexity Theory for a Sustainable Future (search), and Pola Pasvolsky Chair in Conservation Biology at the Percy FitzPatrick Institute of African Ornithology (Cape Town) here continues his novel insights into the dynamic animate nature and health of ecosystems. Akin to an organism’s metabolic homeostasis, living biotas appear to possess an innate propensity for maintaining across space and time their physiological well-being. This is said to be accomplished by way of self-organizing complex adaptive systems that are able to “learn and reason.” With systems philosopher John Collier, a complex resilient (eco)system can then achieves a consistent “identity” as if an “individual” whom maintains key entities and web relationships. As a consequence, since human communities arise from and are situated in a viable biosphere, life’s robust nonlinear network phenomena ought to be intentionally carried forth to create self-sustaining societies. For more, see Cumming's article Heterarchies: Reconciling Networks and Hierarchies in Trends in Ecology and Evolution, online May 2016.

Spatial Resilience is a new and exciting area of interdisciplinary research. It focuses on the influence of spatial variation – including such things as spatial location, context, connectivity, and dispersal – on the resilience of complex systems, and on the roles that resilience and self-organization play in generating spatial variation. In the process, the author ranges from the movements of lions in northern Zimbabwe to the urban jungles of Europe, and from the collapse of past societies to the social impacts of modern conflict. The many case studies and examples discussed in the book show how the concept of spatial resilience can generate valuable insights into the spatial dynamics of social-ecological systems and contribute to solving some of the most pressing problems of our time. (Publisher)

(Resilience is defined as:) (1) the amount of disturbance that a system can absorb while still remaining within the same state or domain of attraction; (2) the degree to which the system is capable of self-organization; and (3) the degree to which the system can build and increase its capacity for learning and adaptation. (13)

De Ruiter, Peter, et al, eds. Dynamic Food Webs: Multispecies Assemblages, Ecosystem Development and Environmental Change. Burlington, MA: Academic Press. December, 2005. A large volume not yet seen whose table of contents on the publisher’s website convey new abilities to understand such ultra-complex phenomena. The result of all these collaborative advances is a new Nature which is no longer a chaotic tangle but suffused by a complementary universality – and by implication a new kind of genesis cosmos.

Delmont, Tom, et al. Structure, Fluctuation and Magnitude of a Natural Grassland Soil Metagenome. ISME Journal. 6/1677, 2012. (Multidisciplinary Journal of Microbial Ecology). A baker’s dozen biologists from the US and UK including Penny Hirsch and Jack Gilbert proceed to interpret and ground this vital ecosystem by way of its composite, encompassing genetic essence. As life sciences lately describe the whole bioworld in terms of an incarnate “meta-omic” basis, might we go on to imagine a genesis uniVerse with a cosmic “metagenome,” an implicate “cosmomic” code? See also a lead note in this issue “Describing Microbial communities and Performing Global Comparisons in the Omic Era,” whence environments can be truly characterized by their innate genomic bioinformation.

Domínguez-García, Virginia and Miguel Muñoz. Ranking Species in Mutualistic Networks.. Nature Scientific Reports.. 5/8182, 2015. As the Abstract explains, University of Granada, Spain, computational biologists give a glimpse into nature’s ubiquitous re-iteration from ecosystems to the worldwide web. The developmental cosmos from which our recognition arises seems graced by an extravagant diversity and a common mathematical source which it manifestly instantiates. Could our appearance and purpose be the way such a universe tries to achieve its own witness and selection?

Understanding the architectural subtleties of ecological networks, believed to confer them enhanced stability and robustness, is a subject of outmost relevance. Mutualistic interactions have been profusely studied and their corresponding bipartite networks, such as plant-pollinator networks, have been reported to exhibit a characteristic “nested” structure. Assessing the importance of any given species in mutualistic networks is a key task when evaluating extinction risks and possible cascade effects. Inspired in a recently introduced algorithm – similar in spirit to Google's PageRank but with a built-in non-linearity– here we propose a method which – by exploiting their nested architecture– allows us to derive a sound ranking of species importance in mutualistic networks. This method clearly outperforms other existing ranking schemes and can become very useful for ecosystem management and biodiversity preservation, where decisions on what aspects of ecosystems to explicitly protect need to be made. (Abstract)

Dunne, Jennifer. The Network Structure of Food Webs. Pascual, Mercedes and Jennifer Dunne, eds. Ecological Networks. Oxford: Oxford University Press, 2006. An extensive historical and topical survey of spatial and temporal topologies and dynamics.

Enquist, Brian, et al. General Patterns of Taxonomic and Biomass Partitioning in Extant and Fossil Plant Communities. Nature. 419/610, 2002. Through complexity theories, the tangled web of forest and field reveals a hierarchical scale where the same form and dynamics hold at each nested level.

The presence of a similar power-function that accounts for over 90% of the variation in taxonomic structure across contemporary and fossil woody plant communities suggests that the processes that promote and/or limit ecological similarity within communities (1) operate in a regular manner across broad geographical gradients, (2) reflect the ecological and evolutionary processes that dictate local composition, (3) uniquely quantify their net influence on community taxonomic structure, and (4) have probably operated in a consistent fashion across woody plant communities for millions of years. (612)

Farnsworth, Keith, et al. Unifying Concepts of Biological Function from Molecules to Ecosystems. Oikos. 126/10, 2017. Farnsworth and Tancredi Caruso, Queen’s University, Belfast, with Larissa Albantakis, University of Wisconsin contribute to a vital, overdue synthesis across ecological theories by way of clarifying definitions, and a range of complexity principles such as autocatalysis and emergent scales. With common, simplified terms in place, the presence of universal formative principles across nature’s tangled bank can at last be realized. See also A Comprehensive Framework for the Study of Species Co-Occurrences, Nestedness and Turnover by Werner Ulrich, et al in the November issue.

The concept of function arises at all levels of biological study and is often loosely and variously defined, especially within ecology. This has led to ambiguity, obscuring the common structure that unites levels of biological organisation, from molecules to ecosystems. Here we build on already successful ideas from molecular biology and complexity theory to create a precise definition of biological function which spans levels of biological organisation and can be quantified in the unifying currency of biomass, enabling comparisons of functional effectiveness (irrespective of the specific function) across the field of ecology. We give precise definitions of ecological and ecosystem function that bring clarity and precision to studies of biodiversity–ecosystem function relationships and questions of ecological redundancy. This type of network structure is that of an autocatalytic set of functional relationships, which also appears at biochemical, cellular and organism levels of organisation, creating a nested hierarchy. This enables a common and unifying concept of function to apply from molecular interaction networks up to the global ecosystem. (Abstract)

Previous   1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10  Next  [More Pages]