Molecular trophic markers in marine food webs and their potential use for coral ecology.

PubMed

Leal, Miguel Costa; Ferrier-Pagès, Christine

2016-10-01

Notable advances in ecological genomics have been driven by high-throughput sequencing technology and taxonomically broad sequence repositories that allow us to accurately assess species interactions with great taxonomic resolution. The use of DNA as a marker for ingested food is particularly relevant to address predator-prey interactions and disentangle complex marine food webs. DNA-based methods benefit from reductionist molecular approaches to address ecosystem scale processes, such as community structure and energy flow across trophic levels, among others. Here we review how molecular trophic markers have been used to better understand trophic interactions in the marine environment and their advantages and limitations. We focus on animal groups where research has been focused, such as marine mammals, seabirds, fishes, pelagic invertebrates and benthic invertebrates, and use case studies to illustrate how DNA-based methods unraveled food-web interactions. The potential of molecular trophic markers for disentangling the complex trophic ecology of corals is also discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Reverse Ecology: from systems to environments and back.

PubMed

Levy, Roie; Borenstein, Elhanan

2012-01-01

The structure of complex biological systems reflects not only their function but also the environments in which they evolved and are adapted to. Reverse Ecology-an emerging new frontier in Evolutionary Systems Biology-aims to extract this information and to obtain novel insights into an organism's ecology. The Reverse Ecology framework facilitates the translation of high-throughput genomic data into large-scale ecological data, and has the potential to transform ecology into a high-throughput field. In this chapter, we describe some of the pioneering work in Reverse Ecology, demonstrating how system-level analysis of complex biological networks can be used to predict the natural habitats of poorly characterized microbial species, their interactions with other species, and universal patterns governing the adaptation of organisms to their environments. We further present several studies that applied Reverse Ecology to elucidate various aspects of microbial ecology, and lay out exciting future directions and potential future applications in biotechnology, biomedicine, and ecological engineering.

Progress and challenges in coupled hydrodynamic-ecological estuarine modeling.

PubMed

Ganju, Neil K; Brush, Mark J; Rashleigh, Brenda; Aretxabaleta, Alfredo L; Del Barrio, Pilar; Grear, Jason S; Harris, Lora A; Lake, Samuel J; McCardell, Grant; O'Donnell, James; Ralston, David K; Signell, Richard P; Testa, Jeremy M; Vaudrey, Jamie M P

2016-03-01

Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear, because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a "theory of everything" for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy.

Progress and challenges in coupled hydrodynamic-ecological estuarine modeling

USGS Publications Warehouse

Ganju, Neil K.; Brush, Mark J.; Rashleigh, Brenda; Aretxabaleta, Alfredo L.; del Barrio, Pilar; Grear, Jason S.; Harris, Lora A.; Lake, Samuel J.; McCardell, Grant; O'Donnell, James; Ralston, David K.; Signell, Richard P.; Testa, Jeremy; Vaudrey, Jamie M. P.

2016-01-01

Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review, we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a “theory of everything” for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy.

Progress and challenges in coupled hydrodynamic-ecological estuarine modeling

PubMed Central

Ganju, Neil K.; Brush, Mark J.; Rashleigh, Brenda; Aretxabaleta, Alfredo L.; del Barrio, Pilar; Grear, Jason S.; Harris, Lora A.; Lake, Samuel J.; McCardell, Grant; O’Donnell, James; Ralston, David K.; Signell, Richard P.; Testa, Jeremy M.; Vaudrey, Jamie M.P.

2016-01-01

Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear, because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a “theory of everything” for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy. PMID:27721675

Comparative analysis of marine ecosystems: workshop on predator-prey interactions.

PubMed

Bailey, Kevin M; Ciannelli, Lorenzo; Hunsicker, Mary; Rindorf, Anna; Neuenfeldt, Stefan; Möllmann, Christian; Guichard, Frederic; Huse, Geir

2010-10-23

Climate and human influences on marine ecosystems are largely manifested by changes in predator-prey interactions. It follows that ecosystem-based management of the world's oceans requires a better understanding of food web relationships. An international workshop on predator-prey interactions in marine ecosystems was held at the Oregon State University, Corvallis, OR, USA on 16-18 March 2010. The meeting brought together scientists from diverse fields of expertise including theoretical ecology, animal behaviour, fish and seabird ecology, statistics, fisheries science and ecosystem modelling. The goals of the workshop were to critically examine the methods of scaling-up predator-prey interactions from local observations to systems, the role of shifting ecological processes with scale changes, and the complexity and organizational structure in trophic interactions.

Social-ecological outcomes in recreational fisheries: The interaction of lakeshore development and stocking

USGS Publications Warehouse

Ziegler, Jacob P.; Golebie, Elizabeth J.; Jones, Stuart E.; Weidel, Brian C.; Solomon, Christopher T.

2017-01-01

Many ecosystems continue to experience rapid transformations due to processes like land use change and resource extraction. A systems approach to maintaining natural resources focuses on how interactions and feedbacks among components of complex social‐ecological systems generate social and ecological outcomes. In recreational fisheries, residential shoreline development and fish stocking are two widespread human behaviors that influence fisheries, yet emergent social‐ecological outcomes from these potentially interacting behaviors remain under explored. We applied a social‐ecological systems framework using a simulation model and empirical data to determine whether lakeshore development is likely to promote stocking through its adverse effects on coarse woody habitat and thereby also on survival of juvenile and adult fish. We demonstrate that high lakeshore development is likely to generate dependency of the ecosystem on the social system, in the form of stocking. Further, lakeshore development can interact with social‐ecological processes to create deficits for state‐level governments, which threatens the ability to fund further ecosystem subsidies. Our results highlight the value of a social‐ecological framework for maintaining ecosystem services like recreational fisheries.

Social-ecological outcomes in recreational fisheries: the interaction of lakeshore development and stocking.

PubMed

Ziegler, Jacob P; Golebie, Elizabeth J; Jones, Stuart E; Weidel, Brian C; Solomon, Christopher T

2017-01-01

Many ecosystems continue to experience rapid transformations due to processes like land use change and resource extraction. A systems approach to maintaining natural resources focuses on how interactions and feedbacks among components of complex social-ecological systems generate social and ecological outcomes. In recreational fisheries, residential shoreline development and fish stocking are two widespread human behaviors that influence fisheries, yet emergent social-ecological outcomes from these potentially interacting behaviors remain under explored. We applied a social-ecological systems framework using a simulation model and empirical data to determine whether lakeshore development is likely to promote stocking through its adverse effects on coarse woody habitat and thereby also on survival of juvenile and adult fish. We demonstrate that high lakeshore development is likely to generate dependency of the ecosystem on the social system, in the form of stocking. Further, lakeshore development can interact with social-ecological processes to create deficits for state-level governments, which threatens the ability to fund further ecosystem subsidies. Our results highlight the value of a social-ecological framework for maintaining ecosystem services like recreational fisheries. © 2016 by the Ecological Society of America.

Scale Model of a Soil Aggregate and Associated Organisms: A Teaching Tool for Soil Ecology

ERIC Educational Resources Information Center

Bruns, Mary Ann; Byrne, Loren B.

2004-01-01

Soil is a complex habitat for diverse biota. A significant challenge in teaching soil ecology is our inability to observe organisms as they live and interact in the soil. The objective of this article is to describe an interactive class project to help students visualize the sizes of different groups of soil organisms and to relate these to soil…

The role of fuels for understanding fire behavior and fire effects

Treesearch

E. Louise Loudermilk; J. Kevin Hiers; Joseph J. O' Brien

2018-01-01

Fire ecology, which has emerged as a critical discipline, links the complex interactions that occur between fire regimes and ecosystems. The ecology of fuels, a first principle in fire ecology, identifies feedbacks between vegetation and fire behavior-a cyclic process that starts with fuels influencing fire behavior, which in turn governs patterns of postfire...

Exploring ecological careers – A new Frontiers series

USDA-ARS?s Scientific Manuscript database

This article provides an the introduction to a series describing non-academic careers in ecology. The world offers many niches for ecologists and the myriad and complex environmental challenges facing us continue to create new career opportunities. Historically, graduate students have interacted cl...

Ecogeographic Genetic Epidemiology

PubMed Central

Sloan, Chantel D.; Duell, Eric J.; Shi, Xun; Irwin, Rebecca; Andrew, Angeline S.; Williams, Scott M.; Moore, Jason H.

2009-01-01

Complex diseases such as cancer and heart disease result from interactions between an individual's genetics and environment, i.e. their human ecology. Rates of complex diseases have consistently demonstrated geographic patterns of incidence, or spatial “clusters” of increased incidence relative to the general population. Likewise, genetic subpopulations and environmental influences are not evenly distributed across space. Merging appropriate methods from genetic epidemiology, ecology and geography will provide a more complete understanding of the spatial interactions between genetics and environment that result in spatial patterning of disease rates. Geographic Information Systems (GIS), which are tools designed specifically for dealing with geographic data and performing spatial analyses to determine their relationship, are key to this kind of data integration. Here the authors introduce a new interdisciplinary paradigm, ecogeographic genetic epidemiology, which uses GIS and spatial statistical analyses to layer genetic subpopulation and environmental data with disease rates and thereby discern the complex gene-environment interactions which result in spatial patterns of incidence. PMID:19025788

Minding the ecological body: neuropsychoanalysis and ecopsychoanalysis.

PubMed

Dodds, Joseph

2013-01-01

Neuropsychoanalysis explores experimentally and theoretically the philosophically ancient discussion of the relation of mind and body, and seems well placed to overcome the problem of a "mindless" neuroscience and a "brainless" psychology and psychotherapy, especially when combined with a greater awareness that the body itself, not only the brain, provides the material substrate for the emergent phenomenon we call mind. However, the mind-brain-body is itself situated within a complex ecological world, interacting with other mind-brain-bodies and the "non-human environment." This occurs both synchronically and diachronically as the organism and its environment (living and non-living) interact in highly complex often non-linear ways. Psychoanalysis can do much to help unmask the anxieties, deficits, conflicts, phantasies, and defenses crucial in understanding the human dimension of the ecological crisis. Yet, psychoanalysis still largely remains not only a "psychology without biology," which neuropsychoanalysis seeks to remedy, but also a "psychology without ecology." Ecopsychoanalysis (Dodds, 2011b; Dodds and Jordan, 2012) is a new transdisciplinary approach drawing on a range of fields such as psychoanalysis, psychology, ecology, philosophy, science, complexity theory, esthetics, and the humanities. It attempts to play with what each approach has to offer in the sense of a heterogeneous assemblage of ideas and processes, mirroring the interlocking complexity, chaos, and turbulence of nature itself. By emphasizing the way the mind-brain-body studied by neuropsychoanalysis is embedded in wider social and ecological networks, ecopsychoanalysis can help open up the relevance of neuropsychoanalysis to wider fields of study, including those who are concerned with what Wilson (2003) called "the future of life."

Translocations as Experiments in the Ecological Resilience of an Asocial Mega-Herbivore

PubMed Central

Linklater, Wayne L.; Gedir, Jay V.; Law, Peter R.; Swaisgood, Ron R.; Adcock, Keryn; du Preez, Pierre; Knight, Michael H.; Kerley, Graham I. H.

2012-01-01

Species translocations are remarkable experiments in evolutionary ecology, and increasingly critical to biodiversity conservation. Elaborate socio-ecological hypotheses for translocation success, based on theoretical fitness relationships, are untested and lead to complex uncertainty rather than parsimonious solutions. We used an extraordinary 89 reintroduction and 102 restocking events releasing 682 black rhinoceros (Diceros bicornis) to 81 reserves in southern Africa (1981–2005) to test the influence of interacting socio-ecological and individual characters on post-release survival. We predicted that the socio-ecological context should feature more prominently after restocking than reintroduction because released rhinoceros interact with resident conspecifics. Instead, an interaction between release cohort size and habitat quality explained reintroduction success but only individuals' ages explained restocking outcomes. Achieving translocation success for many species may not be as complicated as theory suggests. Black rhino, and similarly asocial generalist herbivores without substantial predators, are likely to be resilient to ecological challenges and robust candidates for crisis management in a changing world. PMID:22295100

Translocations as experiments in the ecological resilience of an asocial mega-herbivore.

PubMed

Linklater, Wayne L; Gedir, Jay V; Law, Peter R; Swaisgood, Ron R; Adcock, Keryn; du Preez, Pierre; Knight, Michael H; Kerley, Graham I H

2012-01-01

Species translocations are remarkable experiments in evolutionary ecology, and increasingly critical to biodiversity conservation. Elaborate socio-ecological hypotheses for translocation success, based on theoretical fitness relationships, are untested and lead to complex uncertainty rather than parsimonious solutions. We used an extraordinary 89 reintroduction and 102 restocking events releasing 682 black rhinoceros (Diceros bicornis) to 81 reserves in southern Africa (1981-2005) to test the influence of interacting socio-ecological and individual characters on post-release survival. We predicted that the socio-ecological context should feature more prominently after restocking than reintroduction because released rhinoceros interact with resident conspecifics. Instead, an interaction between release cohort size and habitat quality explained reintroduction success but only individuals' ages explained restocking outcomes. Achieving translocation success for many species may not be as complicated as theory suggests. Black rhino, and similarly asocial generalist herbivores without substantial predators, are likely to be resilient to ecological challenges and robust candidates for crisis management in a changing world.

Ecological hierarchies and self-organisation - Pattern analysis, modelling and process integration across scales

USGS Publications Warehouse

Reuter, H.; Jopp, F.; Blanco-Moreno, J. M.; Damgaard, C.; Matsinos, Y.; DeAngelis, D.L.

2010-01-01

A continuing discussion in applied and theoretical ecology focuses on the relationship of different organisational levels and on how ecological systems interact across scales. We address principal approaches to cope with complex across-level issues in ecology by applying elements of hierarchy theory and the theory of complex adaptive systems. A top-down approach, often characterised by the use of statistical techniques, can be applied to analyse large-scale dynamics and identify constraints exerted on lower levels. Current developments are illustrated with examples from the analysis of within-community spatial patterns and large-scale vegetation patterns. A bottom-up approach allows one to elucidate how interactions of individuals shape dynamics at higher levels in a self-organisation process; e.g., population development and community composition. This may be facilitated by various modelling tools, which provide the distinction between focal levels and resulting properties. For instance, resilience in grassland communities has been analysed with a cellular automaton approach, and the driving forces in rodent population oscillations have been identified with an agent-based model. Both modelling tools illustrate the principles of analysing higher level processes by representing the interactions of basic components.The focus of most ecological investigations on either top-down or bottom-up approaches may not be appropriate, if strong cross-scale relationships predominate. Here, we propose an 'across-scale-approach', closely interweaving the inherent potentials of both approaches. This combination of analytical and synthesising approaches will enable ecologists to establish a more coherent access to cross-level interactions in ecological systems. ?? 2010 Gesellschaft f??r ??kologie.

An experimental test of a fundamental food web motif.

PubMed

Rip, Jason M K; McCann, Kevin S; Lynn, Denis H; Fawcett, Sonia

2010-06-07

Large-scale changes to the world's ecosystem are resulting in the deterioration of biostructure-the complex web of species interactions that make up ecological communities. A difficult, yet crucial task is to identify food web structures, or food web motifs, that are the building blocks of this baroque network of interactions. Once identified, these food web motifs can then be examined through experiments and theory to provide mechanistic explanations for how structure governs ecosystem stability. Here, we synthesize recent ecological research to show that generalist consumers coupling resources with different interaction strengths, is one such motif. This motif amazingly occurs across an enormous range of spatial scales, and so acts to distribute coupled weak and strong interactions throughout food webs. We then perform an experiment that illustrates the importance of this motif to ecological stability. We find that weak interactions coupled to strong interactions by generalist consumers dampen strong interaction strengths and increase community stability. This study takes a critical step by isolating a common food web motif and through clear, experimental manipulation, identifies the fundamental stabilizing consequences of this structure for ecological communities.

Genes, communities & invasive species: understanding the ecological and evolutionary dynamics of host-pathogen interactions.

PubMed

Burdon, J J; Thrall, P H; Ericson, L

2013-08-01

Reciprocal interactions between hosts and pathogens drive ecological, epidemiological and co-evolutionary trajectories, resulting in complex patterns of diversity at population, species and community levels. Recent results confirm the importance of negative frequency-dependent rather than 'arms-race' processes in the evolution of individual host-pathogen associations. At the community level, complex relationships between species abundance and diversity dampen or alter pathogen impacts. Invasive pathogens challenge these controls reflecting the earliest stages of evolutionary associations (akin to arms-race) where disease effects may be so great that they overwhelm the host's and community's ability to respond. Viewing these different stabilization/destabilization phases as a continuum provides a valuable perspective to assessment of the role of genetics and ecology in the dynamics of both natural and invasive host-pathogen associations. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Towards understanding human ecology in nursing practice: a concept analysis].

PubMed

Huynh, Truc; Alderson, Marie

2010-06-01

Human ecology is an umbrella concept encompassing several social, physical, and cultural elements existing in the individual's external environment. The pragmatic utility method was used to analyze the "human ecology" concept in order to ascertain the conceptual fit with nursing epistemology and to promote its use by nurses in clinical practice. Relevant articles for the review were retrieved from the MEDLINE, CINAHL, PsycINFO, and CSA databases using the terms "human ecology," "environment," "nursing," and "ecology." Data analysis revealed that human ecology is perceived as a theoretical perspective designating a complex, multilayered, and multidimensional system, one that comprises individuals and their reciprocal interactions with their global environments and the subsequent impact of these interactions upon their health. Human ecology preconditions include the individuals, their environments, and their transactions. Attributes of this concept encompass the characteristics of an open system (e.g., interdependence, reciprocal).

Arctic systems in the Quaternary: Ecological collision, faunal mosaics and the consequences of wobbling climate

USDA-ARS?s Scientific Manuscript database

Climate oscillations and episodic or recurrent processes interact with evolution, ecology and biogeography determining the structure and complex mosaic that is the biosphere. Parasites and parasite-host assemblages, within an expansive environmental matrix determined by climate, are key components...

Minding the Ecological Body: Neuropsychoanalysis and Ecopsychoanalysis

PubMed Central

Dodds, Joseph

2013-01-01

Neuropsychoanalysis explores experimentally and theoretically the philosophically ancient discussion of the relation of mind and body, and seems well placed to overcome the problem of a “mindless” neuroscience and a “brainless” psychology and psychotherapy, especially when combined with a greater awareness that the body itself, not only the brain, provides the material substrate for the emergent phenomenon we call mind. However, the mind-brain-body is itself situated within a complex ecological world, interacting with other mind-brain-bodies and the “non-human environment.” This occurs both synchronically and diachronically as the organism and its environment (living and non-living) interact in highly complex often non-linear ways. Psychoanalysis can do much to help unmask the anxieties, deficits, conflicts, phantasies, and defenses crucial in understanding the human dimension of the ecological crisis. Yet, psychoanalysis still largely remains not only a “psychology without biology,” which neuropsychoanalysis seeks to remedy, but also a “psychology without ecology.” Ecopsychoanalysis (Dodds, 2011b; Dodds and Jordan, 2012) is a new transdisciplinary approach drawing on a range of fields such as psychoanalysis, psychology, ecology, philosophy, science, complexity theory, esthetics, and the humanities. It attempts to play with what each approach has to offer in the sense of a heterogeneous assemblage of ideas and processes, mirroring the interlocking complexity, chaos, and turbulence of nature itself. By emphasizing the way the mind-brain-body studied by neuropsychoanalysis is embedded in wider social and ecological networks, ecopsychoanalysis can help open up the relevance of neuropsychoanalysis to wider fields of study, including those who are concerned with what Wilson (2003) called “the future of life.” PMID:23533027

Arctic systems in the Quaternary: ecological collision, faunal mosaics and the consequences of a wobbling climate.

PubMed

Hoberg, E P; Cook, J A; Agosta, S J; Boeger, W; Galbreath, K E; Laaksonen, S; Kutz, S J; Brooks, D R

2017-07-01

Climate oscillations and episodic processes interact with evolution, ecology and biogeography to determine the structure and complex mosaic that is the biosphere. Parasites and parasite-host assemblages are key components in a general explanatory paradigm for global biodiversity. We explore faunal assembly in the context of Quaternary time frames of the past 2.6 million years, a period dominated by episodic shifts in climate. Climate drivers cross a continuum from geological to contemporary timescales and serve to determine the structure and distribution of complex biotas. Cycles within cycles are apparent, with drivers that are layered, multifactorial and complex. These cycles influence the dynamics and duration of shifts in environmental structure on varying temporal and spatial scales. An understanding of the dynamics of high-latitude systems, the history of the Beringian nexus (the intermittent land connection linking Eurasia and North America) and downstream patterns of diversity depend on teasing apart the complexity of biotic assembly and persistence. Although climate oscillations have dominated the Quaternary, contemporary dynamics are driven by tipping points and shifting balances emerging from anthropogenic forces that are disrupting ecological structure. Climate change driven by anthropogenic forcing has supplanted a history of episodic variation and is eliminating ecological barriers and constraints on development and distribution for pathogen transmission. A framework to explore interactions of episodic processes on faunal structure and assembly is the Stockholm Paradigm, which appropriately shifts the focus from cospeciation to complexity and contingency in explanations of diversity.

Emergence, institutionalization and renewal: Rhythms of adaptive governance in complex social-ecological systems.

PubMed

Chaffin, Brian C; Gunderson, Lance H

2016-01-01

Adaptive governance provides the capacity for environmental managers and decision makers to confront variable degrees of uncertainty inherent to complex social-ecological systems. Current theoretical conceptualizations of adaptive governance represent a series of structures and processes best suited for either adapting or transforming existing environmental governance regimes towards forms flexible enough to confront rapid ecological change. As the number of empirical examples of adaptive governance described in the literature grows, the conceptual basis of adaptive governance remains largely under theorized. We argue that reconnecting adaptive governance with foundational concepts of ecological resilience-specifically Panarchy and the adaptive cycle of complex systems-highlights the importance of episodic disturbances and cross-scale interactions in triggering reorganizations in governance. By envisioning the processes of adaptive governance through the lens of Panarchy, scholars and practitioners alike will be better able to identify the emergence of adaptive governance, as well as take advantage of opportunities to institutionalize this type of governance in pursuit of sustainability outcomes. The synergistic analysis of adaptive governance and Panarchy can provide critical insight for analyzing the role of social dynamics during oscillating periods of stability and instability in social-ecological systems. A deeper understanding of the potential for cross-scale interactions to shape adaptive governance regimes may be useful as society faces the challenge of mitigating the impacts of global environmental change. Copyright © 2015 Elsevier Ltd. All rights reserved.

Network analysis shining light on parasite ecology and diversity.

PubMed

Poulin, Robert

2010-10-01

The vast number of species making up natural communities, and the myriad interactions among them, pose great difficulties for the study of community structure, dynamics and stability. Borrowed from other fields, network analysis is making great inroads in community ecology and is only now being applied to host-parasite interactions. It allows a complex system to be examined in its entirety, as opposed to one or a few components at a time. This review explores what network analysis is and how it can be used to investigate parasite ecology. It also summarizes the first findings to emerge from network analyses of host-parasite interactions and identifies promising future directions made possible by this approach. Copyright © 2010 Elsevier Ltd. All rights reserved.

Disrupting the Networks of Cancer

PubMed Central

Camacho, Daniel F.; Pienta, Kenneth J.

2014-01-01

Ecosystems are interactive systems involving communities of species and their abiotic environment. Tumors are ecosystems in which cancer cells act as invasive species interacting with native host cell species in an established microenvironment within the larger host biosphere. At its heart, to study ecology is to study interconnectedness. In ecologic science, an ecologic network is a representation of the biotic interactions in an ecosystem in which species (nodes) are connected by pairwise interactions (links). Ecologic networks and signaling network models have been used to describe and compare the structures of ecosystems. It has been shown that disruption of ecologic networks through the loss of species or disruption of interactions between them can lead to the destruction of the ecosystem. Often, the destruction of a single node or link is not enough to disrupt the entire ecosystem. The more complex the network and its interactions, the more difficult it is to cause the extinction of a species, especially without leveraging other aspects of the ecosystem. Similarly, successful treatment of cancer with a single agent is rarely enough to cure a patient without strategically modifying the support systems conducive to survival of cancer. Cancer cells and the ecologic systems they reside in can be viewed as a series of nested networks. The most effective new paradigms for treatment will be developed through application of scaled network disruption. PMID:22442061

Disrupting the networks of cancer.

PubMed

Camacho, Daniel F; Pienta, Kenneth J

2012-05-15

Ecosystems are interactive systems involving communities of species and their abiotic environment. Tumors are ecosystems in which cancer cells act as invasive species interacting with native host cell species in an established microenvironment within the larger host biosphere. At its heart, to study ecology is to study interconnectedness. In ecologic science, an ecologic network is a representation of the biotic interactions in an ecosystem in which species (nodes) are connected by pairwise interactions (links). Ecologic networks and signaling network models have been used to describe and compare the structures of ecosystems. It has been shown that disruption of ecologic networks through the loss of species or disruption of interactions between them can lead to the destruction of the ecosystem. Often, the destruction of a single node or link is not enough to disrupt the entire ecosystem. The more complex the network and its interactions, the more difficult it is to cause the extinction of a species, especially without leveraging other aspects of the ecosystem. Similarly, successful treatment of cancer with a single agent is rarely enough to cure a patient without strategically modifying the support systems conducive to survival of cancer. Cancer cells and the ecologic systems they reside in can be viewed as a series of nested networks. The most effective new paradigms for treatment will be developed through application of scaled network disruption. ©2012 AACR.

Ecological complexity buffers the impacts of future climate on marine consumers

NASA Astrophysics Data System (ADS)

Goldenberg, Silvan U.; Nagelkerken, Ivan; Marangon, Emma; Bonnet, Angélique; Ferreira, Camilo M.; Connell, Sean D.

2018-03-01

Ecological complexity represents a network of interacting components that either propagate or counter the effects of environmental change on individuals and communities1-3. Yet, our understanding of the ecological imprint of ocean acidification (elevated CO2) and climate change (elevated temperature) is largely based on reports of negative effects on single species in simplified laboratory systems4,5. By combining a large mesocosm experiment with a global meta-analysis, we reveal the capacity of consumers (fish and crustaceans) to resist the impacts of elevated CO2. While individual behaviours were impaired by elevated CO2, consumers could restore their performances in more complex environments that allowed for compensatory processes. Consequently, consumers maintained key traits such as foraging, habitat selection and predator avoidance despite elevated CO2 and sustained their populations. Our observed increase in risk-taking under elevated temperature, however, predicts greater vulnerability of consumers to predation. Yet, CO2 as a resource boosted the biomass of consumers through species interactions and may stabilize communities by countering the negative effects of elevated temperature. We conclude that compensatory dynamics inherent in the complexity of nature can buffer the impacts of future climate on species and their communities.

What is microbial community ecology?

PubMed

Konopka, Allan

2009-11-01

The activities of complex communities of microbes affect biogeochemical transformations in natural, managed and engineered ecosystems. Meaningfully defining what constitutes a community of interacting microbial populations is not trivial, but is important for rigorous progress in the field. Important elements of research in microbial community ecology include the analysis of functional pathways for nutrient resource and energy flows, mechanistic understanding of interactions between microbial populations and their environment, and the emergent properties of the complex community. Some emergent properties mirror those analyzed by community ecologists who study plants and animals: biological diversity, functional redundancy and system stability. However, because microbes possess mechanisms for the horizontal transfer of genetic information, the metagenome may also be considered as a community property.

Ecological sites: Organizational tool for outcome-based land management

USDA-ARS?s Scientific Manuscript database

Managing for sustained ecosystem services from rangelands involves complex interactions among soils, plant communities, topography and the prevailing environmental conditions across different land forms from local patches to entire landscapes. This complexity has contributed to prior difficulties in...

Competition for vitamin B1 (thiamin) structures numerous ecological interactions.

PubMed

Kraft, Clifford E; Angert, Esther R

2017-06-01

Thiamin (vitamin B1) is a cofactor required for essential biochemical reactions in all living organisms, yet free thiamin is scarce in the environment. The diversity of biochemical pathways involved in the acquisition, degradation, and synthesis of thiamin indicates that organisms have evolved numerous ecological strategies for meeting this nutritional requirement. In this review we synthesize information from multiple disciplines to show how the complex biochemistry of thiamin influences ecological outcomes of interactions between organisms in environments ranging from the open ocean and the Australian outback to the gastrointestinal tract of animals. We highlight population and ecosystem responses to the availability or absence of thiamin. These include widespread mortality of fishes, birds, and mammals, as well as the thiamin-dependent regulation of ocean productivity. Overall, we portray thiamin biochemistry as the foundation for molecularly mediated ecological interactions that influence survival and abundance of a vast array of organisms.

Bacterial-fungal interactions: ecology, mechanisms and challenges.

PubMed

Deveau, Aurélie; Bonito, Gregory; Uehling, Jessie; Paoletti, Mathieu; Becker, Matthias; Bindschedler, Saskia; Hacquard, Stéphane; Hervé, Vincent; Labbé, Jessy; Lastovetsky, Olga A; Mieszkin, Sophie; Millet, Larry J; Vajna, Balázs; Junier, Pilar; Bonfante, Paola; Krom, Bastiaan P; Olsson, Stefan; van Elsas, Jan Dirk; Wick, Lukas Y

2018-05-01

Fungi and bacteria are found living together in a wide variety of environments. Their interactions are significant drivers of many ecosystem functions and are important for the health of plants and animals. A large number of fungal and bacterial families engage in complex interactions that lead to critical behavioural shifts of the microorganisms ranging from mutualism to antagonism. The importance of bacterial-fungal interactions (BFI) in environmental science, medicine and biotechnology has led to the emergence of a dynamic and multidisciplinary research field that combines highly diverse approaches including molecular biology, genomics, geochemistry, chemical and microbial ecology, biophysics and ecological modelling. In this review, we discuss recent advances that underscore the roles of BFI across relevant habitats and ecosystems. A particular focus is placed on the understanding of BFI within complex microbial communities and in regard of the metaorganism concept. We also discuss recent discoveries that clarify the (molecular) mechanisms involved in bacterial-fungal relationships, and the contribution of new technologies to decipher generic principles of BFI in terms of physical associations and molecular dialogues. Finally, we discuss future directions for research in order to stimulate synergy within the BFI research area and to resolve outstanding questions.

RevEcoR: an R package for the reverse ecology analysis of microbiomes.

PubMed

Cao, Yang; Wang, Yuanyuan; Zheng, Xiaofei; Li, Fei; Bo, Xiaochen

2016-07-29

All species live in complex ecosystems. The structure and complexity of a microbial community reflects not only diversity and function, but also the environment in which it occurs. However, traditional ecological methods can only be applied on a small scale and for relatively well-understood biological systems. Recently, a graph-theory-based algorithm called the reverse ecology approach has been developed that can analyze the metabolic networks of all the species in a microbial community, and predict the metabolic interface between species and their environment. Here, we present RevEcoR, an R package and a Shiny Web application that implements the reverse ecology algorithm for determining microbe-microbe interactions in microbial communities. This software allows users to obtain large-scale ecological insights into species' ecology directly from high-throughput metagenomic data. The software has great potential for facilitating the study of microbiomes. RevEcoR is open source software for the study of microbial community ecology. The RevEcoR R package is freely available under the GNU General Public License v. 2.0 at http://cran.r-project.org/web/packages/RevEcoR/ with the vignette and typical usage examples, and the interactive Shiny web application is available at http://yiluheihei.shinyapps.io/shiny-RevEcoR , or can be installed locally with the source code accessed from https://github.com/yiluheihei/shiny-RevEcoR .

Approaches to advancescientific understanding of macrosystems ecology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levy, Ofir; Ball, Becky; Bond-Lamberty, Benjamin

Macrosystem ecological studies inherently investigate processes that interact across multiple spatial and temporal scales, requiring intensive sampling and massive amounts of data from diverse sources to incorporate complex cross-scale and hierarchical interactions. Inherent challenges associated with these characteristics include high computational demands, data standardization and assimilation, identification of important processes and scales without prior knowledge, and the need for large, cross-disciplinary research teams that conduct long-term studies. Therefore, macrosystem ecology studies must utilize a unique set of approaches that are capable of encompassing these methodological characteristics and associated challenges. Several case studies demonstrate innovative methods used in current macrosystem ecologymore » studies.« less

[Construction and evaluation of ecological network in Poyang Lake Eco-economic Zone, China.

PubMed

Chen, Xiao Ping; Chen, Wen Bo

2016-05-01

Large-scale ecological patches play an important role in regional biodiversity conservation. However, with the rapid progress of China's urbanization, human disturbance on the environment is becoming stronger. Large-scale ecological patches will degrade not only in quantity, but also in quality, threatening the connections among them due to isolation and seriously affecting the biodiversity protection. Taking Poyang Lake Eco-economic Zone as a case, this paper established the potential ecological corridors by minimum cost model and GIS technique taking the impacts of landscape types, slope and human disturbance into consideration. Then, based on gravity quantitative model, we analyzed the intensity of ecological interactions between patches, and the potential ecological corridors were divided into two classes for sake of protection. Finally, the important ecological nodes and breaking points were identified, and the structure of the potential ecological network was analyzed. The results showed that forest and cropland were the main landscape types of ecological corridor composition, interaction between ecological patches differed obviously and the structure of the composed regional ecological network was complex with high connectivity and closure. It might provide a scientific basis for the protection of biodiversity and ecological network optimization in Poyang Lake Eco-economic Zone.

Predator attack rate evolution in space: the role of ecology mediated by complex emergent spatial structure and self-shading.

PubMed

Messinger, Susanna M; Ostling, Annette

2013-11-01

Predation interactions are an important element of ecological communities. Population spatial structure has been shown to influence predator evolution, resulting in the evolution of a reduced predator attack rate; however, the evolutionary role of traits governing predator and prey ecology is unknown. The evolutionary effect of spatial structure on a predator's attack rate has primarily been explored assuming a fixed metapopulation spatial structure, and understood in terms of group selection. But endogenously generated, emergent spatial structure is common in nature. Furthermore, the evolutionary influence of ecological traits may be mediated through the spatial self-structuring process. Drawing from theory on pathogens, the evolutionary effect of emergent spatial structure can be understood in terms of self-shading, where a voracious predator limits its long-term invasion potential by reducing local prey availability. Here we formalize the effects of self-shading for predators using spatial moment equations. Then, through simulations, we show that in a spatial context self-shading leads to relationships between predator-prey ecology and the predator's attack rate that are not expected in a non-spatial context. Some relationships are analogous to relationships already shown for host-pathogen interactions, but others represent new trait dimensions. Finally, since understanding the effects of ecology using existing self-shading theory requires simplifications of the emergent spatial structure that do not apply well here, we also develop metrics describing the complex spatial structure of the predator and prey populations to help us explain the evolutionary effect of predator and prey ecology in the context of self-shading. The identification of these metrics may provide a step towards expansion of the predictive domain of self-shading theory to more complex spatial dynamics. Copyright © 2013 Elsevier Inc. All rights reserved.

Evaluating the Spatio-Temporal Factors that Structure Network Parameters of Plant-Herbivore Interactions

PubMed Central

López-Carretero, Antonio; Díaz-Castelazo, Cecilia; Boege, Karina; Rico-Gray, Víctor

2014-01-01

Despite the dynamic nature of ecological interactions, most studies on species networks offer static representations of their structure, constraining our understanding of the ecological mechanisms involved in their spatio-temporal stability. This is the first study to evaluate plant-herbivore interaction networks on a small spatio-temporal scale. Specifically, we simultaneously assessed the effect of host plant availability, habitat complexity and seasonality on the structure of plant-herbivore networks in a coastal tropical ecosystem. Our results revealed that changes in the host plant community resulting from seasonality and habitat structure are reflected not only in the herbivore community, but also in the emergent properties (network parameters) of the plant-herbivore interaction network such as connectance, selectiveness and modularity. Habitat conditions and periods that are most stressful favored the presence of less selective and susceptible herbivore species, resulting in increased connectance within networks. In contrast, the high degree of selectivennes (i.e. interaction specialization) and modularity of the networks under less stressful conditions was promoted by the diversification in resource use by herbivores. By analyzing networks at a small spatio-temporal scale we identified the ecological factors structuring this network such as habitat complexity and seasonality. Our research offers new evidence on the role of abiotic and biotic factors in the variation of the properties of species interaction networks. PMID:25340790

Predicting community responses to perturbations in the face of imperfect knowledge and network complexity

USGS Publications Warehouse

Novak, M.; Wootton, J.T.; Doak, D.F.; Emmerson, M.; Estes, J.A.; Tinker, M.T.

2011-01-01

How best to predict the effects of perturbations to ecological communities has been a long-standing goal for both applied and basic ecology. This quest has recently been revived by new empirical data, new analysis methods, and increased computing speed, with the promise that ecologically important insights may be obtainable from a limited knowledge of community interactions. We use empirically based and simulated networks of varying size and connectance to assess two limitations to predicting perturbation responses in multispecies communities: (1) the inaccuracy by which species interaction strengths are empirically quantified and (2) the indeterminacy of species responses due to indirect effects associated with network size and structure. We find that even modest levels of species richness and connectance (??25 pairwise interactions) impose high requirements for interaction strength estimates because system indeterminacy rapidly overwhelms predictive insights. Nevertheless, even poorly estimated interaction strengths provide greater average predictive certainty than an approach that uses only the sign of each interaction. Our simulations provide guidance in dealing with the trade-offs involved in maximizing the utility of network approaches for predicting dynamics in multispecies communities. ?? 2011 by the Ecological Society of America.

Ecological suicide in microbes.

PubMed

Ratzke, Christoph; Denk, Jonas; Gore, Jeff

2018-05-01

The growth and survival of organisms often depend on interactions between them. In many cases, these interactions are positive and caused by a cooperative modification of the environment. Examples are the cooperative breakdown of complex nutrients in microbes or the construction of elaborate architectures in social insects, in which the individual profits from the collective actions of her peers. However, organisms can similarly display negative interactions by changing the environment in ways that are detrimental for them, for example by resource depletion or the production of toxic byproducts. Here we find an extreme type of negative interactions, in which Paenibacillus sp. bacteria modify the environmental pH to such a degree that it leads to a rapid extinction of the whole population, a phenomenon that we call ecological suicide. Modification of the pH is more pronounced at higher population densities, and thus ecological suicide is more likely to occur with increasing bacterial density. Correspondingly, promoting bacterial growth can drive populations extinct whereas inhibiting bacterial growth by the addition of harmful substances-such as antibiotics-can rescue them. Moreover, ecological suicide can cause oscillatory dynamics, even in single-species populations. We found ecological suicide in a wide variety of microbes, suggesting that it could have an important role in microbial ecology and evolution.

The role of mites in insect-fungus associations

Treesearch

R. W. Hofstetter; J. C. Moser

2014-01-01

The interactions among insects, mites, and fungi are diverse and complex but poorly understood in most cases. Associations among insects, mites, and fungi span an almost incomprehensible array of ecological interactions and evolutionary histories. Insects and mites often share habitats and resources and thus interact within communities. Many mites and insects rely on...

Mutualism and Antagonism: Ecological Interactions Among Bark Beetles, Mite and Fungi

Treesearch

K.D. Klepzig; J.C. Moser; M.J. Lombardero; M.P. Ayres; R.W. Hofstetter; C.J. Walkinshaw

2001-01-01

Insect-fungal complexes provide challenging and fascinating systems for the study of biotic interactions between plants. plant pathogens, insect vectors and other associated organisms. The types of interactions among these organisms (mutualism. antagonism. parasitism. phoresy. etc.) are as variable as the range of organisms involved (plants, fungi, insects. mites. etc...

Regime shifts and panarchies in regional scale social-ecological water systems

PubMed Central

Gunderson, Lance; Cosens, Barbara A.; Chaffin, Brian C.; (Tom) Arnold, Craig A.; Fremier, Alexander K.; Garmestani, Ahjond S.; Craig, Robin Kundis; Gosnell, Hannah; Birge, Hannah E.; Allen, Craig R.; Benson, Melinda H.; Morrison, Ryan R.; Stone, Mark C.; Hamm, Joseph A.; Nemec, Kristine; Schlager, Edella; Llewellyn, Dagmar

2018-01-01

In this article we summarize histories of nonlinear, complex interactions among societal, legal, and ecosystem dynamics in six North American water basins, as they respond to changing climate. These case studies were chosen to explore the conditions for emergence of adaptive governance in heavily regulated and developed social-ecological systems nested within a hierarchical governmental system. We summarize resilience assessments conducted in each system to provide a synthesis and reference by the other articles in this special feature. We also present a general framework used to evaluate the interactions between society and ecosystem regimes and the governance regimes chosen to mediate those interactions. The case studies show different ways that adaptive governance may be triggered, facilitated, or constrained by ecological and/or legal processes. The resilience assessments indicate that complex interactions among the governance and ecosystem components of these systems can produce different trajectories, which include patterns of (a) development and stabilization, (b) cycles of crisis and recovery, which includes lurches in adaptation and learning, and (3) periods of innovation, novelty, and transformation. Exploration of cross scale (Panarchy) interactions among levels and sectors of government and society illustrate that they may constrain development trajectories, but may also provide stability during crisis or innovation at smaller scales; create crises, but may also facilitate recovery; and constrain system transformation, but may also provide windows of opportunity in which transformation, and the resources to accomplish it, may occur. The framework is the starting point for our exploration of how law might play a role in enhancing the capacity of social-ecological systems to adapt to climate change. PMID:29780427

Regime shifts and panarchies in regional scale social-ecological water systems.

PubMed

Gunderson, Lance; Cosens, Barbara A; Chaffin, Brian C; Tom Arnold, Craig A; Fremier, Alexander K; Garmestani, Ahjond S; Craig, Robin Kundis; Gosnell, Hannah; Birge, Hannah E; Allen, Craig R; Benson, Melinda H; Morrison, Ryan R; Stone, Mark C; Hamm, Joseph A; Nemec, Kristine; Schlager, Edella; Llewellyn, Dagmar

2017-03-17

In this article we summarize histories of nonlinear, complex interactions among societal, legal, and ecosystem dynamics in six North American water basins, as they respond to changing climate. These case studies were chosen to explore the conditions for emergence of adaptive governance in heavily regulated and developed social-ecological systems nested within a hierarchical governmental system. We summarize resilience assessments conducted in each system to provide a synthesis and reference by the other articles in this special feature. We also present a general framework used to evaluate the interactions between society and ecosystem regimes and the governance regimes chosen to mediate those interactions. The case studies show different ways that adaptive governance may be triggered, facilitated, or constrained by ecological and/or legal processes. The resilience assessments indicate that complex interactions among the governance and ecosystem components of these systems can produce different trajectories, which include patterns of (a) development and stabilization, (b) cycles of crisis and recovery, which includes lurches in adaptation and learning, and (3) periods of innovation, novelty, and transformation. Exploration of cross scale (Panarchy) interactions among levels and sectors of government and society illustrate that they may constrain development trajectories, but may also provide stability during crisis or innovation at smaller scales; create crises, but may also facilitate recovery; and constrain system transformation, but may also provide windows of opportunity in which transformation, and the resources to accomplish it, may occur. The framework is the starting point for our exploration of how law might play a role in enhancing the capacity of social-ecological systems to adapt to climate change.

Regime shifts and panarchies in regional scale social-ecological water systems

USGS Publications Warehouse

Gunderson, Lance; Cosens, Barbara; Chaffin, Brian C.; Arnold, Craig Anthony (Tony); Fremier, Alexander K.; Garmestani, Ahjond S.; Kundis Craig, Robin; Gosnell, Hannah; Birge, Hannah E.; Allen, Craig R.; Benson, Melinda H.; Morrison, Ryan R.; Stone, Mark; Hamm, Joseph A.; Nemec, Kristine T.; Schlager, Edella; Llewellyn, Dagmar

2017-01-01

In this article we summarize histories of nonlinear, complex interactions among societal, legal, and ecosystem dynamics in six North American water basins, as they respond to changing climate. These case studies were chosen to explore the conditions for emergence of adaptive governance in heavily regulated and developed social-ecological systems nested within a hierarchical governmental system. We summarize resilience assessments conducted in each system to provide a synthesis and reference by the other articles in this special feature. We also present a general framework used to evaluate the interactions between society and ecosystem regimes and the governance regimes chosen to mediate those interactions. The case studies show different ways that adaptive governance may be triggered, facilitated, or constrained by ecological and/or legal processes. The resilience assessments indicate that complex interactions among the governance and ecosystem components of these systems can produce different trajectories, which include patterns of (a) development and stabilization, (b) cycles of crisis and recovery, which includes lurches in adaptation and learning, and (3) periods of innovation, novelty, and transformation. Exploration of cross scale (Panarchy) interactions among levels and sectors of government and society illustrate that they may constrain development trajectories, but may also provide stability during crisis or innovation at smaller scales; create crises, but may also facilitate recovery; and constrain system transformation, but may also provide windows of opportunity in which transformation, and the resources to accomplish it, may occur. The framework is the starting point for our exploration of how law might play a role in enhancing the capacity of social-ecological systems to adapt to climate change.

Pattern-oriented modeling of agent-based complex systems: Lessons from ecology

USGS Publications Warehouse

Grimm, Volker; Revilla, Eloy; Berger, Uta; Jeltsch, Florian; Mooij, Wolf M.; Railsback, Steven F.; Thulke, Hans-Hermann; Weiner, Jacob; Wiegand, Thorsten; DeAngelis, Donald L.

2005-01-01

Agent-based complex systems are dynamic networks of many interacting agents; examples include ecosystems, financial markets, and cities. The search for general principles underlying the internal organization of such systems often uses bottom-up simulation models such as cellular automata and agent-based models. No general framework for designing, testing, and analyzing bottom-up models has yet been established, but recent advances in ecological modeling have come together in a general strategy we call pattern-oriented modeling. This strategy provides a unifying framework for decoding the internal organization of agent-based complex systems and may lead toward unifying algorithmic theories of the relation between adaptive behavior and system complexity.

Pattern-Oriented Modeling of Agent-Based Complex Systems: Lessons from Ecology

NASA Astrophysics Data System (ADS)

Grimm, Volker; Revilla, Eloy; Berger, Uta; Jeltsch, Florian; Mooij, Wolf M.; Railsback, Steven F.; Thulke, Hans-Hermann; Weiner, Jacob; Wiegand, Thorsten; DeAngelis, Donald L.

2005-11-01

Agent-based complex systems are dynamic networks of many interacting agents; examples include ecosystems, financial markets, and cities. The search for general principles underlying the internal organization of such systems often uses bottom-up simulation models such as cellular automata and agent-based models. No general framework for designing, testing, and analyzing bottom-up models has yet been established, but recent advances in ecological modeling have come together in a general strategy we call pattern-oriented modeling. This strategy provides a unifying framework for decoding the internal organization of agent-based complex systems and may lead toward unifying algorithmic theories of the relation between adaptive behavior and system complexity.

Food-web complexity, meta-community complexity and community stability.

PubMed

Mougi, A; Kondoh, M

2016-04-13

What allows interacting, diverse species to coexist in nature has been a central question in ecology, ever since the theoretical prediction that a complex community should be inherently unstable. Although the role of spatiality in species coexistence has been recognized, its application to more complex systems has been less explored. Here, using a meta-community model of food web, we show that meta-community complexity, measured by the number of local food webs and their connectedness, elicits a self-regulating, negative-feedback mechanism and thus stabilizes food-web dynamics. Moreover, the presence of meta-community complexity can give rise to a positive food-web complexity-stability effect. Spatiality may play a more important role in stabilizing dynamics of complex, real food webs than expected from ecological theory based on the models of simpler food webs.

A Single-Granule-Level Approach Reveals Ecological Heterogeneity in an Upflow Anaerobic Sludge Blanket Reactor

PubMed Central

Mei, Ran; Narihiro, Takashi; Bocher, Benjamin T. W.; Yamaguchi, Takashi; Liu, Wen-Tso

2016-01-01

Upflow anaerobic sludge blanket (UASB) reactor has served as an effective process to treat industrial wastewater such as purified terephthalic acid (PTA) wastewater. For optimal UASB performance, balanced ecological interactions between syntrophs, methanogens, and fermenters are critical. However, much of the interactions remain unclear because UASB have been studied at a “macro”-level perspective of the reactor ecosystem. In reality, such reactors are composed of a suite of granules, each forming individual micro-ecosystems treating wastewater. Thus, typical approaches may be oversimplifying the complexity of the microbial ecology and granular development. To identify critical microbial interactions at both macro- and micro- level ecosystem ecology, we perform community and network analyses on 300 PTA–degrading granules from a lab-scale UASB reactor and two full-scale reactors. Based on MiSeq-based 16S rRNA gene sequencing of individual granules, different granule-types co-exist in both full-scale reactors regardless of granule size and reactor sampling depth, suggesting that distinct microbial interactions occur in different granules throughout the reactor. In addition, we identify novel networks of syntrophic metabolic interactions in different granules, perhaps caused by distinct thermodynamic conditions. Moreover, unseen methanogenic relationships (e.g. “Candidatus Aminicenantes” and Methanosaeta) are observed in UASB reactors. In total, we discover unexpected microbial interactions in granular micro-ecosystems supporting UASB ecology and treatment through a unique single-granule level approach. PMID:27936088

Ecology of zoonotic infectious diseases in bats: current knowledge and future directions

USGS Publications Warehouse

Hayman, D.T.; Bowen, R.A.; Cryan, P.M.; McCracken, G.F.; O'Shea, T.J.; Peel, A.J.; Gilbert, A.; Webb, C.T.; Wood, J.L.

2013-01-01

Bats are hosts to a range of zoonotic and potentially zoonotic pathogens. Human activities that increase exposure to bats will likely increase the opportunity for infections to spill over in the future. Ecological drivers of pathogen spillover and emergence in novel hosts, including humans, involve a complex mixture of processes, and understanding these complexities may aid in predicting spillover. In particular, only once the pathogen and host ecologies are known can the impacts of anthropogenic changes be fully appreciated. Cross-disciplinary approaches are required to understand how host and pathogen ecology interact. Bats differ from other sylvatic disease reservoirs because of their unique and diverse lifestyles, including their ability to fly, often highly gregarious social structures, long lifespans and low fecundity rates. We highlight how these traits may affect infection dynamics and how both host and pathogen traits may interact to affect infection dynamics. We identify key questions relating to the ecology of infectious diseases in bats and propose that a combination of field and laboratory studies are needed to create data-driven mechanistic models to elucidate those aspects of bat ecology that are most critical to the dynamics of emerging bat viruses. If commonalities can be found, then predicting the dynamics of newly emerging diseases may be possible. This modelling approach will be particularly important in scenarios when population surveillance data are unavailable and when it is unclear which aspects of host ecology are driving infection dynamics.

Ecology of Zoonotic Infectious Diseases in Bats: Current Knowledge and Future Directions

PubMed Central

Hayman, D T S; Bowen, R A; Cryan, P M; McCracken, G F; O’Shea, T J; Peel, A J; Gilbert, A; Webb, C T; Wood, J L N

2013-01-01

Bats are hosts to a range of zoonotic and potentially zoonotic pathogens. Human activities that increase exposure to bats will likely increase the opportunity for infections to spill over in the future. Ecological drivers of pathogen spillover and emergence in novel hosts, including humans, involve a complex mixture of processes, and understanding these complexities may aid in predicting spillover. In particular, only once the pathogen and host ecologies are known can the impacts of anthropogenic changes be fully appreciated. Cross-disciplinary approaches are required to understand how host and pathogen ecology interact. Bats differ from other sylvatic disease reservoirs because of their unique and diverse lifestyles, including their ability to fly, often highly gregarious social structures, long lifespans and low fecundity rates. We highlight how these traits may affect infection dynamics and how both host and pathogen traits may interact to affect infection dynamics. We identify key questions relating to the ecology of infectious diseases in bats and propose that a combination of field and laboratory studies are needed to create data-driven mechanistic models to elucidate those aspects of bat ecology that are most critical to the dynamics of emerging bat viruses. If commonalities can be found, then predicting the dynamics of newly emerging diseases may be possible. This modelling approach will be particularly important in scenarios when population surveillance data are unavailable and when it is unclear which aspects of host ecology are driving infection dynamics. PMID:22958281

A Metabarcoding Survey on the Fungal Microbiota Associated to the Olive Fruit Fly.

PubMed

Malacrinò, Antonino; Schena, Leonardo; Campolo, Orlando; Laudani, Francesca; Mosca, Saveria; Giunti, Giulia; Strano, Cinzia Patricia; Palmeri, Vincenzo

2017-04-01

The occurrence of interaction between insects and fungi is interesting from an ecological point of view, particularly when these interactions involve insect pests and plant pathogens within an agroecosystem. In this study, we aimed to perform an accurate analysis on the fungal microbiota associated to Bactrocera oleae (Rossi) through a metabarcoding approach based on 454 pyrosequencing. From this analysis, we retrieved 43,549 reads that clustered into 128 operational taxonomic units (OTUs), of which 29 resulted in the "core" associate fungi of B. oleae. This fungal community was mainly represented by sooty mould fungi, such as Cladosporium spp., Alternaria spp. and Aureobasidium spp., by plant pathogens like Colletotrichum spp. and Pseudocercospora spp., along with several other less abundant taxa whose ecology is unclear in most of the cases. Our findings lead to new insights into the microbial ecology of this specific ecological niche, enabling the understanding of a complex network of interactions within the olive agroecosystem.

Simple processes drive unpredictable differences in estuarine fish assemblages: Baselines for understanding site-specific ecological and anthropogenic impacts

NASA Astrophysics Data System (ADS)

Sheaves, Marcus

2016-03-01

Predicting patterns of abundance and composition of biotic assemblages is essential to our understanding of key ecological processes, and our ability to monitor, evaluate and manage assemblages and ecosystems. Fish assemblages often vary from estuary to estuary in apparently unpredictable ways, making it challenging to develop a general understanding of the processes that determine assemblage composition. This makes it problematic to transfer understanding from one estuary situation to another and therefore difficult to assemble effective management plans or to assess the impacts of natural and anthropogenic disturbance. Although system-to-system variability is a common property of ecological systems, rather than being random it is the product of complex interactions of multiple causes and effects at a variety of spatial and temporal scales. I investigate the drivers of differences in estuary fish assemblages, to develop a simple model explaining the diversity and complexity of observed estuary-to-estuary differences, and explore its implications for management and conservation. The model attributes apparently unpredictable differences in fish assemblage composition from estuary to estuary to the interaction of species-specific, life history-specific and scale-specific processes. In explaining innate faunal differences among estuaries without the need to invoke complex ecological or anthropogenic drivers, the model provides a baseline against which the effects of additional natural and anthropogenic factors can be evaluated.

Ecology of fire in shortgrass prairie of the southern Great Plains

Treesearch

Paulette L. Ford; Guy R. McPherson

1996-01-01

The ecology of fire in shortgrass prairie of the southern Great Plains includes a complex interaction between the shortgrass prairie ecosystem and its inhabitants, all inextricably linked to land-use patterns. The history of the relationship between man and fire has been filled with ambivalence and mistrust, along with an appreciation of the power of fire as a...

Inferring interactions in complex microbial communities from nucleotide sequence data and environmental parameters

PubMed Central

Shang, Yu; Sikorski, Johannes; Bonkowski, Michael; Fiore-Donno, Anna-Maria; Kandeler, Ellen; Marhan, Sven; Boeddinghaus, Runa S.; Solly, Emily F.; Schrumpf, Marion; Schöning, Ingo; Wubet, Tesfaye; Buscot, Francois; Overmann, Jörg

2017-01-01

Interactions occur between two or more organisms affecting each other. Interactions are decisive for the ecology of the organisms. Without direct experimental evidence the analysis of interactions is difficult. Correlation analyses that are based on co-occurrences are often used to approximate interaction. Here, we present a new mathematical model to estimate the interaction strengths between taxa, based on changes in their relative abundances across environmental gradients. PMID:28288199

Multiple dimensions of transitions in complex socio-ecological systems - A case from China

NASA Astrophysics Data System (ADS)

Liu, Wei; Yang, Wu; Vina, Andres; Schröter, Dagmar; Liu, Jianguo

2013-04-01

Transitions in complex socio-ecological systems are intermediate phases between two successive and more stable periods or states and involve various societal, ecological, and biophysical changes that are often non-linear and inter-related. Understanding transitions is challenging but important for managing socio-ecological systems for achieving environmental sustainability and improving human well-being. Long-term and intensive research is warranted to disclose common patterns and mechanisms of socio-ecological transitions and to develop ideas and methods for studying and planning sustainable transitions. Based on a long-term research on human-nature relationships in Wolong Nature Reserve in China, we studied multiple concurrent social, economic, and ecological transitions during the last 15 years. As a UNESCO biosphere reserve, Wolong lies within a global biodiversity hotspot and a World Heritage site. It contains the largest populations of the world-famous endangered giant pandas and several thousand other animal and plant species. Like most nature reserves in China and many other developing countries, Wolong is also home to many local residents who undertake a variety of activities that involve interaction with ecosystem. For the majority of the 20th century, local people in Wolong lived under poverty line in a closed subsistence-based agricultural economy. Their demands on for wood (as fuel and raw materials) from the natural forests were high and resulted in severe deforestation, habitat degradation, and landslides. Since late 1990s, a series of major economic (e.g., tourism development) and environmental (e.g., payment for ecosystem services programs) policies have been implemented in the reserve as adaptive strategies to cope with poverty and ecological degradation. Within a decade, we have observed major transitions in land use (i.e., from extractive use to non-consumptive use), economic structure (i.e., from a subsistence-based agricultural economy to an open economy relying on tourism and cash crop), and energy consumption (i.e., decline in biomass fuel by three quarters and tripling in electricity use). We further analyzed their impacts on local people's well-being and discuss the possible explanatory framework for the observed socio-ecological transition as a whole. This study not only has direct implications for sustainability transition in developing countries but also increases our understanding of the complexity of human-nature interactions and their effects on the resilience of complex socio-ecological systems.

Synchronization unveils the organization of ecological networks with positive and negative interactions

NASA Astrophysics Data System (ADS)

Girón, Andrea; Saiz, Hugo; Bacelar, Flora S.; Andrade, Roberto F. S.; Gómez-Gardeñes, Jesús

2016-06-01

Network science has helped to understand the organization principles of the interactions among the constituents of large complex systems. However, recently, the high resolution of the data sets collected has allowed to capture the different types of interactions coexisting within the same system. A particularly important example is that of systems with positive and negative interactions, a usual feature appearing in social, neural, and ecological systems. The interplay of links of opposite sign presents natural difficulties for generalizing typical concepts and tools applied to unsigned networks and, moreover, poses some questions intrinsic to the signed nature of the network, such as how are negative interactions balanced by positive ones so to allow the coexistence and survival of competitors/foes within the same system? Here, we show that synchronization phenomenon is an ideal benchmark for uncovering such balance and, as a byproduct, to assess which nodes play a critical role in the overall organization of the system. We illustrate our findings with the analysis of synthetic and real ecological networks in which facilitation and competitive interactions coexist.

Predicting community responses to perturbations in the face of imperfect knowledge and network complexity

USGS Publications Warehouse

Novak, Mark; Wootton, J. Timothy; Doak, Daniel F.; Emmerson, Mark; Estes, James A.; Tinker, M. Timothy

2011-01-01

How best to predict the effects of perturbations to ecological communities has been a long-standing goal for both applied and basic ecology. This quest has recently been revived by new empirical data, new analysis methods, and increased computing speed, with the promise that ecologically important insights may be obtainable from a limited knowledge of community interactions. We use empirically based and simulated networks of varying size and connectance to assess two limitations to predicting perturbation responses in multispecies communities: (1) the inaccuracy by which species interaction strengths are empirically quantified and (2) the indeterminacy of species responses due to indirect effects associated with network size and structure. We find that even modest levels of species richness and connectance (∼25 pairwise interactions) impose high requirements for interaction strength estimates because system indeterminacy rapidly overwhelms predictive insights. Nevertheless, even poorly estimated interaction strengths provide greater average predictive certainty than an approach that uses only the sign of each interaction. Our simulations provide guidance in dealing with the trade-offs involved in maximizing the utility of network approaches for predicting dynamics in multispecies communities.

Instructional Context and Student Motivation, Learning, and Development: Commentary and Implications for School Psychologists

ERIC Educational Resources Information Center

Pendergast, Laura L.; Kaplan, Avi

2015-01-01

From an ecological perspective, learning and development in childhood and throughout the lifespan occur in the context of interactions within complex social networks. Collectively, the articles in this special issue illuminate three important themes related to teacher-student interactions within instructional contexts: relationships, competence,…

Relative importance of evolutionary dynamics depends on the composition of microbial predator-prey community.

PubMed

Friman, Ville-Petri; Dupont, Alessandra; Bass, David; Murrell, David J; Bell, Thomas

2016-06-01

Community dynamics are often studied in subsets of pairwise interactions. Scaling pairwise interactions back to the community level is, however, problematic because one given interaction might not reflect ecological and evolutionary outcomes of other functionally similar species interactions or capture the emergent eco-evolutionary dynamics arising only in more complex communities. Here we studied this experimentally by exposing Pseudomonas fluorescens SBW25 prey bacterium to four different protist predators (Tetrahymena pyriformis, Tetrahymena vorax, Chilomonas paramecium and Acanthamoeba polyphaga) in all possible single-predator, two-predator and four-predator communities for hundreds of prey generations covering both ecological and evolutionary timescales. We found that only T. pyriformis selected for prey defence in single-predator communities. Although T. pyriformis selection was constrained in the presence of the intraguild predator, T. vorax, T. pyriformis selection led to evolution of specialised prey defence strategies in the presence of C. paramecium or A. polyphaga. At the ecological level, adapted prey populations were phenotypically more diverse, less stable and less productive compared with non-adapted prey populations. These results suggest that predator community composition affects the relative importance of ecological and evolutionary processes and can crucially determine when rapid evolution has the potential to change ecological properties of microbial communities.

Relative importance of evolutionary dynamics depends on the composition of microbial predator–prey community

PubMed Central

Friman, Ville-Petri; Dupont, Alessandra; Bass, David; Murrell, David J; Bell, Thomas

2016-01-01

Community dynamics are often studied in subsets of pairwise interactions. Scaling pairwise interactions back to the community level is, however, problematic because one given interaction might not reflect ecological and evolutionary outcomes of other functionally similar species interactions or capture the emergent eco-evolutionary dynamics arising only in more complex communities. Here we studied this experimentally by exposing Pseudomonas fluorescens SBW25 prey bacterium to four different protist predators (Tetrahymena pyriformis, Tetrahymena vorax, Chilomonas paramecium and Acanthamoeba polyphaga) in all possible single-predator, two-predator and four-predator communities for hundreds of prey generations covering both ecological and evolutionary timescales. We found that only T. pyriformis selected for prey defence in single-predator communities. Although T. pyriformis selection was constrained in the presence of the intraguild predator, T. vorax, T. pyriformis selection led to evolution of specialised prey defence strategies in the presence of C. paramecium or A. polyphaga. At the ecological level, adapted prey populations were phenotypically more diverse, less stable and less productive compared with non-adapted prey populations. These results suggest that predator community composition affects the relative importance of ecological and evolutionary processes and can crucially determine when rapid evolution has the potential to change ecological properties of microbial communities. PMID:26684728

Land use, water and Mediterranean landscapes: modelling long-term dynamics of complex socio-ecological systems.

PubMed

Barton, C Michael; Ullah, Isaac I; Bergin, Sean

2010-11-28

The evolution of Mediterranean landscapes during the Holocene has been increasingly governed by the complex interactions of water and human land use. Different land-use practices change the amount of water flowing across the surface and infiltrating the soil, and change water's ability to move surface sediments. Conversely, water amplifies the impacts of human land use and extends the ecological footprint of human activities far beyond the borders of towns and fields. Advances in computational modelling offer new tools to study the complex feedbacks between land use, land cover, topography and surface water. The Mediterranean Landscape Dynamics project (MedLand) is building a modelling laboratory where experiments can be carried out on the long-term impacts of agropastoral land use, and whose results can be tested against the archaeological record. These computational experiments are providing new insights into the socio-ecological consequences of human decisions at varying temporal and spatial scales.

Why infectious disease research needs community ecology

PubMed Central

Johnson, Pieter T. J.; de Roode, Jacobus C.; Fenton, Andy

2016-01-01

Infectious diseases often emerge from interactions among multiple species and across nested levels of biological organization. Threats as diverse as Ebola virus, human malaria, and bat white-nose syndrome illustrate the need for a mechanistic understanding of the ecological interactions underlying emerging infections. We describe how recent advances in community ecology can be adopted to address contemporary challenges in disease research. These analytical tools can identify the factors governing complex assemblages of multiple hosts, parasites, and vectors, and reveal how processes link across scales from individual hosts to regions. They can also determine the drivers of heterogeneities among individuals, species, and regions to aid targeting of control strategies. We provide examples where these principles have enhanced disease management and illustrate how they can be further extended. PMID:26339035

Process Network Approach to Understanding How Forest Ecosystems Adapt to Changes

NASA Astrophysics Data System (ADS)

Kim, J.; Yun, J.; Hong, J.; Kwon, H.; Chun, J.

2011-12-01

Sustainability challenges are transforming science and its role in society. Complex systems science has emerged as an inevitable field of education and research, which transcends disciplinary boundaries and focuses on understanding of the dynamics of complex social-ecological systems (SES). SES is a combined system of social and ecological components and drivers that interact and give rise to results, which could not be understood on the basis of sociological or ecological considerations alone. However, both systems may be viewed as a network of processes, and such a network hierarchy may serve as a hinge to bridge social and ecological systems. As a first step toward such effort, we attempted to delineate and interpret such process networks in forest ecosystems, which play a critical role in the cycles of carbon and water from local to global scales. These cycles and their variability, in turn, play an important role in the emergent and self-organizing interactions between forest ecosystems and their environment. Ruddell and Kumar (2009) define a process network as a network of feedback loops and the related time scales, which describe the magnitude and direction of the flow of energy, matter, and information between the different variables in a complex system. Observational evidence, based on micrometeorological eddy covariance measurements, suggests that heterogeneity and disturbances in forest ecosystems in monsoon East Asia may facilitate to build resilience for adaptation to change. Yet, the principles that characterize the role of variability in these interactions remain elusive. In this presentation, we report results from the analysis of multivariate ecohydrologic and biogeochemical time series data obtained from temperate forest ecosystems in East Asia based on information flow statistics.

Ecosystem services classification: A systems ecology perspective of the cascade framework.

PubMed

La Notte, Alessandra; D'Amato, Dalia; Mäkinen, Hanna; Paracchini, Maria Luisa; Liquete, Camino; Egoh, Benis; Geneletti, Davide; Crossman, Neville D

2017-03-01

Ecosystem services research faces several challenges stemming from the plurality of interpretations of classifications and terminologies. In this paper we identify two main challenges with current ecosystem services classification systems: i) the inconsistency across concepts, terminology and definitions, and; ii) the mix up of processes and end-state benefits, or flows and assets. Although different ecosystem service definitions and interpretations can be valuable for enriching the research landscape, it is necessary to address the existing ambiguity to improve comparability among ecosystem-service-based approaches. Using the cascade framework as a reference, and Systems Ecology as a theoretical underpinning, we aim to address the ambiguity across typologies. The cascade framework links ecological processes with elements of human well-being following a pattern similar to a production chain. Systems Ecology is a long-established discipline which provides insight into complex relationships between people and the environment. We present a refreshed conceptualization of ecosystem services which can support ecosystem service assessment techniques and measurement. We combine the notions of biomass, information and interaction from system ecology, with the ecosystem services conceptualization to improve definitions and clarify terminology. We argue that ecosystem services should be defined as the interactions (i.e. processes) of the ecosystem that produce a change in human well-being, while ecosystem components or goods, i.e. countable as biomass units, are only proxies in the assessment of such changes. Furthermore, Systems Ecology can support a re-interpretation of the ecosystem services conceptualization and related applied research, where more emphasis is needed on the underpinning complexity of the ecological system.

A large-scale perspective on ecosystems

NASA Technical Reports Server (NTRS)

Mizutani, Hiroshi

1987-01-01

Interactions between ecological elements must be better understood in order to construct an ecological life support system in space. An index was devised to describe the complexity of material cyclings within a given ecosystem. It was then applied to the cyclings of bioelements in various systems of material cyclings including the whole Earth and national economies. The results show interesting characteristics of natural and man-made systems.

Ecological Complexity in a Coffee Agroecosystem: Spatial Heterogeneity, Population Persistence and Biological Control

PubMed Central

Liere, Heidi; Jackson, Doug; Vandermeer, John

2012-01-01

Background Spatial heterogeneity is essential for the persistence of many inherently unstable systems such as predator-prey and parasitoid-host interactions. Since biological interactions themselves can create heterogeneity in space, the heterogeneity necessary for the persistence of an unstable system could be the result of local interactions involving elements of the unstable system itself. Methodology/Principal Findings Here we report on a predatory ladybird beetle whose natural history suggests that the beetle requires the patchy distribution of the mutualism between its prey, the green coffee scale, and the arboreal ant, Azteca instabilis. Based on known ecological interactions and the natural history of the system, we constructed a spatially-explicit model and showed that the clustered spatial pattern of ant nests facilitates the persistence of the beetle populations. Furthermore, we show that the dynamics of the beetle consuming the scale insects can cause the clustered distribution of the mutualistic ants in the first place. Conclusions/Significance From a theoretical point of view, our model represents a novel situation in which a predator indirectly causes a spatial pattern of an organism other than its prey, and in doing so facilitates its own persistence. From a practical point of view, it is noteworthy that one of the elements in the system is a persistent pest of coffee, an important world commodity. This pest, we argue, is kept within limits of control through a complex web of ecological interactions that involves the emergent spatial pattern. PMID:23029061

Novel Seimatosporium species from grapevine in northern California and their interactions with fungal pathogens involved in the trunk-disease complex

USDA-ARS?s Scientific Manuscript database

Seimatosporium species and closely related ‘pestalotioid fungi’ have been isolated from vineyards around the world, but their ecological status in grapevine wood is not equivocal. To determine their involvement in the grapevine trunk-disease complex, we tested the pathogenicity of California isolate...

Living in the branches: population dynamics and ecological processes in dendritic networks

USGS Publications Warehouse

Grant, E.H.C.; Lowe, W.H.; Fagan, W.F.

2007-01-01

Spatial structure regulates and modifies processes at several levels of ecological organization (e.g. individual/genetic, population and community) and is thus a key component of complex systems, where knowledge at a small scale can be insufficient for understanding system behaviour at a larger scale. Recent syntheses outline potential applications of network theory to ecological systems, but do not address the implications of physical structure for network dynamics. There is a specific need to examine how dendritic habitat structure, such as that found in stream, hedgerow and cave networks, influences ecological processes. Although dendritic networks are one type of ecological network, they are distinguished by two fundamental characteristics: (1) both the branches and the nodes serve as habitat, and (2) the specific spatial arrangement and hierarchical organization of these elements interacts with a species' movement behaviour to alter patterns of population distribution and abundance, and community interactions. Here, we summarize existing theory relating to ecological dynamics in dendritic networks, review empirical studies examining the population- and community-level consequences of these networks, and suggest future research integrating spatial pattern and processes in dendritic systems.

How Structured Is the Entangled Bank? The Surprisingly Simple Organization of Multiplex Ecological Networks Leads to Increased Persistence and Resilience

PubMed Central

Wieters, Evie A.; Navarrete, Sergio A.

2016-01-01

Species are linked to each other by a myriad of positive and negative interactions. This complex spectrum of interactions constitutes a network of links that mediates ecological communities’ response to perturbations, such as exploitation and climate change. In the last decades, there have been great advances in the study of intricate ecological networks. We have, nonetheless, lacked both the data and the tools to more rigorously understand the patterning of multiple interaction types between species (i.e., “multiplex networks”), as well as their consequences for community dynamics. Using network statistical modeling applied to a comprehensive ecological network, which includes trophic and diverse non-trophic links, we provide a first glimpse at what the full “entangled bank” of species looks like. The community exhibits clear multidimensional structure, which is taxonomically coherent and broadly predictable from species traits. Moreover, dynamic simulations suggest that this non-random patterning of how diverse non-trophic interactions map onto the food web could allow for higher species persistence and higher total biomass than expected by chance and tends to promote a higher robustness to extinctions. PMID:27487303

The statistical power to detect cross-scale interactions at macroscales

USGS Publications Warehouse

Wagner, Tyler; Fergus, C. Emi; Stow, Craig A.; Cheruvelil, Kendra S.; Soranno, Patricia A.

2016-01-01

Macroscale studies of ecological phenomena are increasingly common because stressors such as climate and land-use change operate at large spatial and temporal scales. Cross-scale interactions (CSIs), where ecological processes operating at one spatial or temporal scale interact with processes operating at another scale, have been documented in a variety of ecosystems and contribute to complex system dynamics. However, studies investigating CSIs are often dependent on compiling multiple data sets from different sources to create multithematic, multiscaled data sets, which results in structurally complex, and sometimes incomplete data sets. The statistical power to detect CSIs needs to be evaluated because of their importance and the challenge of quantifying CSIs using data sets with complex structures and missing observations. We studied this problem using a spatially hierarchical model that measures CSIs between regional agriculture and its effects on the relationship between lake nutrients and lake productivity. We used an existing large multithematic, multiscaled database, LAke multiscaled GeOSpatial, and temporal database (LAGOS), to parameterize the power analysis simulations. We found that the power to detect CSIs was more strongly related to the number of regions in the study rather than the number of lakes nested within each region. CSI power analyses will not only help ecologists design large-scale studies aimed at detecting CSIs, but will also focus attention on CSI effect sizes and the degree to which they are ecologically relevant and detectable with large data sets.

Approaches to understanding the impact of life-history features on plant-pathogen co-evolutionary dynamics

Treesearch

Jeremy J. Burdon; Peter H. Thrall; Adnane Nemri

2012-01-01

Natural plant-pathogen associations are complex interactions in which the interplay of environment, host, and pathogen factors results in spatially heterogeneous ecological and epidemiological dynamics. The evolutionary patterns that result from the interaction of these factors are still relatively poorly understood. Recently, integration of the appropriate spatial and...

Using landscape disturbance and succession models to support forest management

Treesearch

Eric J. Gustafson; Brian R. Sturtevant; Anatoly S. Shvidenko; Robert M. Scheller

2010-01-01

Managers of forested landscapes must account for multiple, interacting ecological processes operating at broad spatial and temporal scales. These interactions can be of such complexity that predictions of future forest ecosystem states are beyond the analytical capability of the human mind. Landscape disturbance and succession models (LDSM) are predictive and...

Fluvial biogeomorphology in the Anthropocene: Managing rivers and managing landscapes.

NASA Astrophysics Data System (ADS)

Viles, Heather

2015-04-01

Biogeomorphology considers the many, and often complex, interactions between ecological and geomorphological processes. The concept of the Anthropocene deserves greater attention by scientists working on biogeomorphology, as will be demonstrated in this talk though a focus on fluvial environments. Rivers and river systems have been the subject of long-term human interference and management across the world, often in the form of direct manipulation of biogeomorphic interactions. Up to the present three broadly-defined phases of the Anthropocene can be identified - the Palaeoanthropocene, the Industrial Revolution and the Great Acceleration. Each of these broad phases of the Anthropocene has different implications for fluvial biogeomorphology and river management. The nature and dynamics of tufa-depositing systems provide good examples of the differing Anthropocene situations and will be focused on in this talk. We may now be entering a fourth phase of the Anthropocene called 'Earth system stewardship'. In terms of better understanding and managing the biogeomorphic interactions within rivers in such a phase, an improved conceptualisation of the Anthropocene and the complex web of interactions between human, ecological and geomorphological processes is needed.

Climate and dengue transmission: evidence and implications.

PubMed

Morin, Cory W; Comrie, Andrew C; Ernst, Kacey

2013-01-01

Climate influences dengue ecology by affecting vector dynamics, agent development, and mosquito/human interactions. Although these relationships are known, the impact climate change will have on transmission is unclear. Climate-driven statistical and process-based models are being used to refine our knowledge of these relationships and predict the effects of projected climate change on dengue fever occurrence, but results have been inconsistent. We sought to identify major climatic influences on dengue virus ecology and to evaluate the ability of climate-based dengue models to describe associations between climate and dengue, simulate outbreaks, and project the impacts of climate change. We reviewed the evidence for direct and indirect relationships between climate and dengue generated from laboratory studies, field studies, and statistical analyses of associations between vectors, dengue fever incidence, and climate conditions. We assessed the potential contribution of climate-driven, process-based dengue models and provide suggestions to improve their performance. Relationships between climate variables and factors that influence dengue transmission are complex. A climate variable may increase dengue transmission potential through one aspect of the system while simultaneously decreasing transmission potential through another. This complexity may at least partly explain inconsistencies in statistical associations between dengue and climate. Process-based models can account for the complex dynamics but often omit important aspects of dengue ecology, notably virus development and host-species interactions. Synthesizing and applying current knowledge of climatic effects on all aspects of dengue virus ecology will help direct future research and enable better projections of climate change effects on dengue incidence.

The feasibility of equilibria in large ecosystems: A primary but neglected concept in the complexity-stability debate

PubMed Central

Dougoud, Michaël; Rohr, Rudolf P.

2018-01-01

The consensus that complexity begets stability in ecosystems was challenged in the seventies, a result recently extended to ecologically-inspired networks. The approaches assume the existence of a feasible equilibrium, i.e. with positive abundances. However, this key assumption has not been tested. We provide analytical results complemented by simulations which show that equilibrium feasibility vanishes in species rich systems. This result leaves us in the uncomfortable situation in which the existence of a feasible equilibrium assumed in local stability criteria is far from granted. We extend our analyses by changing interaction structure and intensity, and find that feasibility and stability is warranted irrespective of species richness with weak interactions. Interestingly, we find that the dynamical behaviour of ecologically inspired architectures is very different and richer than that of unstructured systems. Our results suggest that a general understanding of ecosystem dynamics requires focusing on the interplay between interaction strength and network architecture. PMID:29420532

Microorganisms living on macroalgae: diversity, interactions, and biotechnological applications.

PubMed

Martin, Marjolaine; Portetelle, Daniel; Michel, Gurvan; Vandenbol, Micheline

2014-04-01

Marine microorganisms play key roles in every marine ecological process, hence the growing interest in studying their populations and functions. Microbial communities on algae remain underexplored, however, despite their huge biodiversity and the fact that they differ markedly from those living freely in seawater. The study of this microbiota and of its relationships with algal hosts should provide crucial information for ecological investigations on algae and aquatic ecosystems. Furthermore, because these microorganisms interact with algae in multiple, complex ways, they constitute an interesting source of novel bioactive compounds with biotechnological potential, such as dehalogenases, antimicrobials, and alga-specific polysaccharidases (e.g., agarases, carrageenases, and alginate lyases). Here, to demonstrate the huge potential of alga-associated organisms and their metabolites in developing future biotechnological applications, we first describe the immense diversity and density of these microbial biofilms. We further describe their complex interactions with algae, leading to the production of specific bioactive compounds and hydrolytic enzymes of biotechnological interest. We end with a glance at their potential use in medical and industrial applications.

Decoupling of body-plan diversification and ecological structuring during the Ediacaran–Cambrian transition: evolutionary and geobiological feedbacks

PubMed Central

Mángano, M. Gabriela; Buatois, Luis A.

2014-01-01

The rapid appearance of bilaterian clades at the beginning of the Phanerozoic is one of the most intriguing topics in macroevolution. However, the complex feedbacks between diversification and ecological interactions are still poorly understood. Here, we show that a systematic and comprehensive analysis of the trace-fossil record of the Ediacaran–Cambrian transition indicates that body-plan diversification and ecological structuring were decoupled. The appearance of a wide repertoire of behavioural strategies and body plans occurred by the Fortunian. However, a major shift in benthic ecological structure, recording the establishment of a suspension-feeder infauna, increased complexity of the trophic web, and coupling of benthos and plankton took place during Cambrian Stage 2. Both phases were accompanied by different styles of ecosystem engineering, but only the second one resulted in the establishment of the Phanerozoic-style ecology. In turn, the suspension-feeding infauna may have been the ecological drivers of a further diversification of deposit-feeding strategies by Cambrian Stage 3, favouring an ecological spillover scenario. Trace-fossil information strongly supports the Cambrian explosion, but allows for a short time of phylogenetic fuse during the terminal Ediacaran–Fortunian. PMID:24523279

Decoupling of body-plan diversification and ecological structuring during the Ediacaran-Cambrian transition: evolutionary and geobiological feedbacks.

PubMed

Mángano, M Gabriela; Buatois, Luis A

2014-04-07

The rapid appearance of bilaterian clades at the beginning of the Phanerozoic is one of the most intriguing topics in macroevolution. However, the complex feedbacks between diversification and ecological interactions are still poorly understood. Here, we show that a systematic and comprehensive analysis of the trace-fossil record of the Ediacaran-Cambrian transition indicates that body-plan diversification and ecological structuring were decoupled. The appearance of a wide repertoire of behavioural strategies and body plans occurred by the Fortunian. However, a major shift in benthic ecological structure, recording the establishment of a suspension-feeder infauna, increased complexity of the trophic web, and coupling of benthos and plankton took place during Cambrian Stage 2. Both phases were accompanied by different styles of ecosystem engineering, but only the second one resulted in the establishment of the Phanerozoic-style ecology. In turn, the suspension-feeding infauna may have been the ecological drivers of a further diversification of deposit-feeding strategies by Cambrian Stage 3, favouring an ecological spillover scenario. Trace-fossil information strongly supports the Cambrian explosion, but allows for a short time of phylogenetic fuse during the terminal Ediacaran-Fortunian.

Trophic interaction modifications: an empirical and theoretical framework.

PubMed

Terry, J Christopher D; Morris, Rebecca J; Bonsall, Michael B

2017-10-01

Consumer-resource interactions are often influenced by other species in the community. At present these 'trophic interaction modifications' are rarely included in ecological models despite demonstrations that they can drive system dynamics. Here, we advocate and extend an approach that has the potential to unite and represent this key group of non-trophic interactions by emphasising the change to trophic interactions induced by modifying species. We highlight the opportunities this approach brings in comparison to frameworks that coerce trophic interaction modifications into pairwise relationships. To establish common frames of reference and explore the value of the approach, we set out a range of metrics for the 'strength' of an interaction modification which incorporate increasing levels of contextual information about the system. Through demonstrations in three-species model systems, we establish that these metrics capture complimentary aspects of interaction modifications. We show how the approach can be used in a range of empirical contexts; we identify as specific gaps in current understanding experiments with multiple levels of modifier species and the distributions of modifications in networks. The trophic interaction modification approach we propose can motivate and unite empirical and theoretical studies of system dynamics, providing a route to confront ecological complexity. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

More than a meal: integrating non-feeding interactions into food webs

USGS Publications Warehouse

Kéfi, Sonia; Berlow, Eric L.; Wieters, Evie A.; Navarrete, Sergio A.; Petchey, Owen L.; Wood, Spencer A.; Boit, Alice; Joppa, Lucas N.; Lafferty, Kevin D.; Williams, Richard J.; Martinez, Neo D.; Menge, Bruce A.; Blanchette, Carol A.; Iles, Alison C.; Brose, Ulrich

2012-01-01

Organisms eating each other are only one of many types of well documented and important interactions among species. Other such types include habitat modification, predator interference and facilitation. However, ecological network research has been typically limited to either pure food webs or to networks of only a few (<3) interaction types. The great diversity of non-trophic interactions observed in nature has been poorly addressed by ecologists and largely excluded from network theory. Herein, we propose a conceptual framework that organises this diversity into three main functional classes defined by how they modify specific parameters in a dynamic food web model. This approach provides a path forward for incorporating non-trophic interactions in traditional food web models and offers a new perspective on tackling ecological complexity that should stimulate both theoretical and empirical approaches to understanding the patterns and dynamics of diverse species interactions in nature.

Acorns Alive.

ERIC Educational Resources Information Center

Matthews, Catherine; Vickers, Valerie; Patrick, Patricia

2002-01-01

Introduces a lesson plan on the role of the acorn and its complex community of biotic relationships between animal and fungal organisms. Introduces students to ecological concepts through acorn investigations including dissection of acorns and exploring the organisms' interaction web. (YDS)

Component modeling in ecological risk assessment: Disturbance in interspecific interactions caused by air toxics introduced into terrestrial ecosystems

NASA Astrophysics Data System (ADS)

Swider, Jan Zenon

The human health risk assessment (HRA), initiated by the onset of nuclear industry, has been a well established methodology for assessing the impacts of human created contamination on an individual human being and entire population. The wide spread of applications and tools grown upon this methodology allows one not only to identify the hazards, but also to manage the risks. Recently, there has existed an increased awareness of the need to conduct ecological risk assessments (ERA) in addition to HRAs. The ERAs are, by and large, more complex than typical HRAs and involve not only different species but whole ecological systems. Such complex analyses require a thorough understanding of the processes underway in the ecosystem, including the contaminant transport through the food web, population dynamics as well as intra- and inter-specific relationships. The exposure pathways change radically depending on the consumer tier. Plants produce their nutriment from the sunlight and raw inorganic compounds. Animals and other living forms obtain energy by eating plants, other animals and detritus. Their double role as food consumers and food producers causes a trophic structure of the ecological system, where nutrients and energy are transferred from one trophic level to another. This is a dynamic process of energy flow, mostly in the form of food, varying with time and space. In order to conduct an efficient ERA, a multidisciplinary framework is needed. This framework can be enhanced by analyzing predator-prey interactions during the environmental disturbances caused by a pollutant emission, and by assessing the consequences of such disturbances. It is necessary to develop a way to describe how human industrial activity affects the ecosystems. Existing ecological studies have mostly been focused either on pure ecological interdependencies or on limited perspectives of human activities. In this study, we discuss the issues of air pollution and its ecological impacts from the Ecological Risk Assessment standpoint and examine the impact of air toxics emissions on an ecosystem, with particular emphasis on predator-prey interactions. Such analysis may help to identify the most likely conditions leading to the ecosystem instability and possibility of its recuperation.

Is sociality required for the evolution of communicative complexity? Evidence weighed against alternative hypotheses in diverse taxonomic groups

PubMed Central

Ord, Terry J.; Garcia-Porta, Joan

2012-01-01

Complex social communication is expected to evolve whenever animals engage in many and varied social interactions; that is, sociality should promote communicative complexity. Yet, informal comparisons among phylogenetically independent taxonomic groups seem to cast doubt on the putative role of social factors in the evolution of complex communication. Here, we provide a formal test of the sociality hypothesis alongside alternative explanations for the evolution of communicative complexity. We compiled data documenting variations in signal complexity among closely related species for several case study groups—ants, frogs, lizards and birds—and used new phylogenetic methods to investigate the factors underlying communication evolution. Social factors were only implicated in the evolution of complex visual signals in lizards. Ecology, and to some degree allometry, were most likely explanations for complexity in the vocal signals of frogs (ecology) and birds (ecology and allometry). There was some evidence for adaptive evolution in the pheromone complexity of ants, although no compelling selection pressure was identified. For most taxa, phylogenetic null models were consistently ranked above adaptive models and, for some taxa, signal complexity seems to have accumulated in species via incremental or random changes over long periods of evolutionary time. Becoming social presumably leads to the origin of social communication in animals, but its subsequent influence on the trajectory of signal evolution has been neither clear-cut nor general among taxonomic groups. PMID:22641820

Can you sequence ecology? Metagenomics of adaptive diversification.

PubMed

Marx, Christopher J

2013-01-01

Few areas of science have benefited more from the expansion in sequencing capability than the study of microbial communities. Can sequence data, besides providing hypotheses of the functions the members possess, detect the evolutionary and ecological processes that are occurring? For example, can we determine if a species is adapting to one niche, or if it is diversifying into multiple specialists that inhabit distinct niches? Fortunately, adaptation of populations in the laboratory can serve as a model to test our ability to make such inferences about evolution and ecology from sequencing. Even adaptation to a single niche can give rise to complex temporal dynamics due to the transient presence of multiple competing lineages. If there are multiple niches, this complexity is augmented by segmentation of the population into multiple specialists that can each continue to evolve within their own niche. For a known example of parallel diversification that occurred in the laboratory, sequencing data gave surprisingly few obvious, unambiguous signs of the ecological complexity present. Whereas experimental systems are open to direct experimentation to test hypotheses of selection or ecological interaction, the difficulty in "seeing ecology" from sequencing for even such a simple system suggests translation to communities like the human microbiome will be quite challenging. This will require both improved empirical methods to enhance the depth and time resolution for the relevant polymorphisms and novel statistical approaches to rigorously examine time-series data for signs of various evolutionary and ecological phenomena within and between species.

Soil ecological interactions: comparisons between tropical and subalpine forests

Treesearch

Grizelle Gonzalez; Ruth E. Ley; Steven K. Schmidt; Xiaoming Zou; Timothy R. Seastedt

2001-01-01

Soil fauna can influence soil processes through interactions with the microbial community. Due to the complexity of the functional roles of fauna and their effects on microbes, little consensus has been reached on the extent to which soil fauna can regulate microbial activities. We quantified soil microbial biomass and maximum growth rates in control and fauna-excluded...

Wildfire risk as a socioecological pathology

Treesearch

A Paige Fischer; Thomas A Spies; Toddi A Steelman; Cassandra Moseley; Bart R Johnson; John D Bailey; Alan A Ager; Patrick Bourgeron; Susan Charnley; Brandon M Collins; Jeff Kline; Jessica E Leahy; Jeremy S Littell; James DA Millington; Max Nielsen-Pincus; Christine S Olsen; Travis B Paveglio; Christopher I Roos; Michelle M Steen-Adams; Forrest R Stevens; Jelena Vukomanovic; Eric White; David MJS Bowman

2016-01-01

Wildfire risk in temperate forests has become a nearly intractable problem that can be characterized as a socioecological “pathology”: that is, a set of complex and problematic interactions among social and ecological systems across multiple spatial and temporal scales. Assessments of wildfire risk could benefit from recognizing and accounting for these interactions in...

Plant host finding by parasitic plants: A new perspective on plant to plant communication

Treesearch

Mark C. Mescher; Justin B. Runyon; Consuelo M. De Moraes

2006-01-01

Plants release airborne chemicals that can convey ecologically relevant information to other organisms. These plant volatiles are known to mediate a large array of, often complex, interactions between plants and insects. It has been suggested that plant volatiles may have similar importance in mediating interactions among plant species, but there are few well-...

Bioactive Molecules in Soil Ecosystems: Masters of the Underground

PubMed Central

Zhuang, Xuliang; Gao, Jie; Ma, Anzhou; Fu, Shenglei; Zhuang, Guoqiang

2013-01-01

Complex biological and ecological processes occur in the rhizosphere through ecosystem-level interactions between roots, microorganisms and soil fauna. Over the past decade, studies of the rhizosphere have revealed that when roots, microorganisms and soil fauna physically contact one another, bioactive molecular exchanges often mediate these interactions as intercellular signal, which prepare the partners for successful interactions. Despite the importance of bioactive molecules in sustainable agriculture, little is known of their numerous functions, and improving plant health and productivity by altering ecological processes remains difficult. In this review, we describe the major bioactive molecules present in below-ground ecosystems (i.e., flavonoids, exopolysaccharides, antibiotics and quorum-sensing signals), and we discuss how these molecules affect microbial communities, nutrient availability and plant defense responses. PMID:23615474

Plant host finding by parasitic plants: a new perspective on plant to plant communication.

PubMed

Mescher, Mark C; Runyon, Justin B; De Moraes, Consuelo M

2006-11-01

Plants release airborne chemicals that can convey ecologically relevant information to other organisms. These plant volatiles are known to mediate a large array of, often complex, interactions between plants and insects. It has been suggested that plant volatiles may have similar importance in mediating interactions among plant species, but there are few well-documented examples of plant-to-plant communication via volatiles, and the ecological significance of such interactions has been much debated. To date, nearly all studies of volatile-mediated interactions among plant species have focused on the reception of herbivore-induced volatiles by neighboring plants. We recently documented volatile effects in another system, demonstrating that the parasitic plant Cuscuta pentagona uses volatile cues to locate its hosts. This finding may broaden the discussion regarding plant-to-plant communication, and suggests that new classes of volatile-meditated interactions among plant species await discovery.

The cystic fibrosis microbiome in an ecological perspective and its impact in antibiotic therapy.

PubMed

Magalhães, Andreia P; Azevedo, Nuno F; Pereira, Maria O; Lopes, Susana P

2016-02-01

The recent focus on the cystic fibrosis (CF) complex microbiome has led to the recognition that the microbes can interact between them and with the host immune system, affecting the disease progression and treatment routes. Although the main focus remains on the interactions between traditional pathogens, growing evidence supports the contribution and the role of emergent species. Understanding the mechanisms and the biological effects involved in polymicrobial interactions may be the key to improve effective therapies and also to define new strategies for disease control. This review focuses on the interactions between microbe-microbe and host-microbe, from an ecological point of view, discussing their impact on CF disease progression. There are increasing indications that these interactions impact the success of antimicrobial therapy. Consequently, a new approach where therapy is personalized to patients by taking into account their individual CF microbiome is suggested.

Interactions Among Plants, Insects, and Microbes: Elucidation of Inter-Organismal Chemical Communications in Agricultural Ecology.

PubMed

Beck, John J; Alborn, Hans; Block, Anna; Christensen, Shawn A; Hunter, Charles T; Rering, Caitlin C; Seidl-Adams, Irmgard; Stuhl, Charles; Torto, Baldwyn; Tumlinson, James H

2018-06-12

The last two decades have witnessed a sustained increase in the study of plant-emitted volatiles and their role in plant-insect, plant-microbe and plant-plant interactions. While each of these binary systems involves complex chemical and biochemical processes between two organisms, the progression of increasing complexity of a ternary system (i.e., plant-insect-microbe), and the study of a ternary system requires non-trivial planning. This planning can include: an experimental design that factors in potential overarching ecological interactions regarding the binary or ternary system; correctly identifying and understanding unexpected observations that may occur during the experiment; and, thorough interpretation of the resultant data. This challenge of planning, performing and interpreting a plant's defensive response to multiple biotic stressors will be even greater when abiotic stressors (i.e., temperature or water) are factored into the system. To fully understand the system, we need to not only continue to investigate and understand the volatile profiles, but also include and understand the biochemistry of the plant's response to these stressors. In this paper, we provide examples and discuss interaction considerations with respect to how readers and future authors of the Journal of Agricultural and Food Chemistry can contribute their expertise toward the extraction and interpretation of chemical information exchanged between agricultural commodities and their associated pests. This holistic, multidisciplinary and thoughtful approach to interactions of plants, insects, and microbes, and the resultant response of the plants, can lead to a better understanding of agricultural ecology, in turn leading to practical and viable solutions to agricultural problems.

The spatiotemporal system dynamics of acquired resistance in an engineered microecology.

PubMed

Datla, Udaya Sree; Mather, William H; Chen, Sheng; Shoultz, Isaac W; Täuber, Uwe C; Jones, Caroline N; Butzin, Nicholas C

2017-11-22

Great strides have been made in the understanding of complex networks; however, our understanding of natural microecologies is limited. Modelling of complex natural ecological systems has allowed for new findings, but these models typically ignore the constant evolution of species. Due to the complexity of natural systems, unanticipated interactions may lead to erroneous conclusions concerning the role of specific molecular components. To address this, we use a synthetic system to understand the spatiotemporal dynamics of growth and to study acquired resistance in vivo. Our system differs from earlier synthetic systems in that it focuses on the evolution of a microecology from a killer-prey relationship to coexistence using two different non-motile Escherichia coli strains. Using empirical data, we developed the first ecological model emphasising the concept of the constant evolution of species, where the survival of the prey species is dependent on location (distance from the killer) or the evolution of resistance. Our simple model, when expanded to complex microecological association studies under varied spatial and nutrient backgrounds may help to understand the complex relationships between multiple species in intricate natural ecological networks. This type of microecological study has become increasingly important, especially with the emergence of antibiotic-resistant pathogens.

Current Challenges in Plant Eco-Metabolomics

PubMed Central

Peters, Kristian; Worrich, Anja; Alka, Oliver; Balcke, Gerd; Bruelheide, Helge; Dietz, Sophie; Dührkop, Kai; Heinig, Uwe; Kücklich, Marlen; Müller, Caroline; Poeschl, Yvonne; Pohnert, Georg; Ruttkies, Christoph; Schweiger, Rabea; Shahaf, Nir; Tortosa, Maria; Ueberschaar, Nico; Velasco, Pablo; Weiß, Brigitte M.; van Dam, Nicole M.

2018-01-01

The relatively new research discipline of Eco-Metabolomics is the application of metabolomics techniques to ecology with the aim to characterise biochemical interactions of organisms across different spatial and temporal scales. Metabolomics is an untargeted biochemical approach to measure many thousands of metabolites in different species, including plants and animals. Changes in metabolite concentrations can provide mechanistic evidence for biochemical processes that are relevant at ecological scales. These include physiological, phenotypic and morphological responses of plants and communities to environmental changes and also interactions with other organisms. Traditionally, research in biochemistry and ecology comes from two different directions and is performed at distinct spatiotemporal scales. Biochemical studies most often focus on intrinsic processes in individuals at physiological and cellular scales. Generally, they take a bottom-up approach scaling up cellular processes from spatiotemporally fine to coarser scales. Ecological studies usually focus on extrinsic processes acting upon organisms at population and community scales and typically study top-down and bottom-up processes in combination. Eco-Metabolomics is a transdisciplinary research discipline that links biochemistry and ecology and connects the distinct spatiotemporal scales. In this review, we focus on approaches to study chemical and biochemical interactions of plants at various ecological levels, mainly plant–organismal interactions, and discuss related examples from other domains. We present recent developments and highlight advancements in Eco-Metabolomics over the last decade from various angles. We further address the five key challenges: (1) complex experimental designs and large variation of metabolite profiles; (2) feature extraction; (3) metabolite identification; (4) statistical analyses; and (5) bioinformatics software tools and workflows. The presented solutions to these challenges will advance connecting the distinct spatiotemporal scales and bridging biochemistry and ecology. PMID:29734799

Stochastic ecological network occupancy (SENO) models: a new tool for modeling ecological networks across spatial scales

USGS Publications Warehouse

Lafferty, Kevin D.; Dunne, Jennifer A.

2010-01-01

Stochastic ecological network occupancy (SENO) models predict the probability that species will occur in a sample of an ecological network. In this review, we introduce SENO models as a means to fill a gap in the theoretical toolkit of ecologists. As input, SENO models use a topological interaction network and rates of colonization and extinction (including consumer effects) for each species. A SENO model then simulates the ecological network over time, resulting in a series of sub-networks that can be used to identify commonly encountered community modules. The proportion of time a species is present in a patch gives its expected probability of occurrence, whose sum across species gives expected species richness. To illustrate their utility, we provide simple examples of how SENO models can be used to investigate how topological complexity, species interactions, species traits, and spatial scale affect communities in space and time. They can categorize species as biodiversity facilitators, contributors, or inhibitors, making this approach promising for ecosystem-based management of invasive, threatened, or exploited species.

Complex Behavior of Contaminant Flux and the Ecology of the Lower Mississippi River

NASA Astrophysics Data System (ADS)

Barton, C. C.; Manheim, F. T.; De Cola, L.; Bollinger, J. E.; Jenkins, J. A.

2001-12-01

This presentation is an overview of a collaborative NSF/USGS/Tulane funded multi-scale study of the Lower Mississippi River system. The study examines the system in three major dimensional realms: space, time, and complexity (systems and their hierarchies). Researchers at Tulane University and the U.S. Geological Survey have initiated a collaborative effort to undertake the study of interacting elements which directly or indirectly affect the water quality, ecology and physical condition of the Mississippi River. These researchers include experts in the fields of water quality chemistry, geochemistry, hydrologic modeling, bioengineering, biology, fish ecology, statistics, complexity analysis, epidemiology, and computer science. Underlying this research are large databases that permit quantitative analysis of the system over the past 40 years. Results to date show that the variation in discharge and the contaminant flux scale independently both exhibit fractal scaling, the signature geometry of nonlinear dynamical and complex systems. Public perception is that the Lower Mississippi River is a health hazard, but for the past decade, traditional water quality measurements show that contaminants are within current regulatory guidelines for human consumption. This difference between public perception and scientific reality represents a complex scientific and social issue. The connections and feedback within the ecological system and the Mississippi River are few because engineering structures isolate the lower Mississippi River from its surroundings. Investigation of the connections and feedback between human health and the ecological health of the River and the surrounding region as well as perceptions of these states of health - holds promise for explaining epidemiological patterns of human disease.

Feasibility and coexistence of large ecological communities.

PubMed

Grilli, Jacopo; Adorisio, Matteo; Suweis, Samir; Barabás, György; Banavar, Jayanth R; Allesina, Stefano; Maritan, Amos

2017-02-24

The role of species interactions in controlling the interplay between the stability of ecosystems and their biodiversity is still not well understood. The ability of ecological communities to recover after small perturbations of the species abundances (local asymptotic stability) has been well studied, whereas the likelihood of a community to persist when the conditions change (structural stability) has received much less attention. Our goal is to understand the effects of diversity, interaction strengths and ecological network structure on the volume of parameter space leading to feasible equilibria. We develop a geometrical framework to study the range of conditions necessary for feasible coexistence. We show that feasibility is determined by few quantities describing the interactions, yielding a nontrivial complexity-feasibility relationship. Analysing more than 100 empirical networks, we show that the range of coexistence conditions in mutualistic systems can be analytically predicted. Finally, we characterize the geometric shape of the feasibility domain, thereby identifying the direction of perturbations that are more likely to cause extinctions.

"Generality of mis-fit"? The real-life difficulty of matching scales in an interconnected world.

PubMed

Keskitalo, E Carina H; Horstkotte, Tim; Kivinen, Sonja; Forbes, Bruce; Käyhkö, Jukka

2016-10-01

A clear understanding of processes at multiple scales and levels is of special significance when conceiving strategies for human-environment interactions. However, understanding and application of the scale concept often differ between administrative-political and ecological disciplines. These mirror major differences in potential solutions whether and how scales can, at all, be made congruent. As a result, opportunities of seeking "goodness-of-fit" between different concepts of governance should perhaps be reconsidered in the light of a potential "generality of mis-fit." This article reviews the interdisciplinary considerations inherent in the concept of scale in its ecological, as well as administrative-political, significance and argues that issues of how to manage "mis-fit" should be awarded more emphasis in social-ecological research and management practices. These considerations are exemplified by the case of reindeer husbandry in Fennoscandia. Whilst an indigenous small-scale practice, reindeer husbandry involves multi-level ecological and administrative-political complexities-complexities that we argue may arise in any multi-level system.

Navigating the Perfect Storm: Research Strategies for Socialecological Systems in a Rapidly Evolving World

NASA Astrophysics Data System (ADS)

Dearing, John A.; Bullock, Seth; Costanza, Robert; Dawson, Terry P.; Edwards, Mary E.; Poppy, Guy M.; Smith, Graham M.

2012-04-01

The `Perfect Storm' metaphor describes a combination of events that causes a surprising or dramatic impact. It lends an evolutionary perspective to how social-ecological interactions change. Thus, we argue that an improved understanding of how social-ecological systems have evolved up to the present is necessary for the modelling, understanding and anticipation of current and future social-ecological systems. Here we consider the implications of an evolutionary perspective for designing research approaches. One desirable approach is the creation of multi-decadal records produced by integrating palaeoenvironmental, instrument and documentary sources at multiple spatial scales. We also consider the potential for improved analytical and modelling approaches by developing system dynamical, cellular and agent-based models, observing complex behaviour in social-ecological systems against which to test systems dynamical theory, and drawing better lessons from history. Alongside these is the need to find more appropriate ways to communicate complex systems, risk and uncertainty to the public and to policy-makers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whicker, Jeffrey J; Field, Jason P; Belnap, Jayne

Emission and redistribution of dust due to wind erosion in drylands drives major biogeochemical dynamics and provides important aeolian environmental connectivity at scales from individual plants up to the global scale. Yet, perhaps because most relevant research on aeolian processes has been presented in a geosciences rather than ecological context, most ecological studies do not explicitly consider dust-driven processes. To bridge this disciplinary gap, we provide a general overview of the ecological importance of dust, examine complex interactions between wind erosion and ecosystem dynamics from the plant-interspace scale to regional and global scales, and highlight specific examples of how disturbancemore » affects these interactions and their consequences. Changes in climate and intensification of land use will both likely lead to increased dust production. To address these challenges, environmental scientists, land managers and policy makers need to more explicitly consider dust in resource management decisions.« less

Dynamic Plant-Plant-Herbivore Interactions Govern Plant Growth-Defence Integration.

PubMed

de Vries, Jorad; Evers, Jochem B; Poelman, Erik H

2017-04-01

Plants downregulate their defences against insect herbivores upon impending competition for light. This has long been considered a resource trade-off, but recent advances in plant physiology and ecology suggest this mechanism is more complex. Here we propose that to understand why plants regulate and balance growth and defence, the complex dynamics in plant-plant competition and plant-herbivore interactions needs to be considered. Induced growth-defence responses affect plant competition and herbivore colonisation in space and time, which has consequences for the adaptive value of these responses. Assessing these complex interactions strongly benefits from advanced modelling tools that can model multitrophic interactions in space and time. Such an exercise will allow a critical re-evaluation why and how plants integrate defence and competition for light. Copyright © 2016 Elsevier Ltd. All rights reserved.

[From anthropocentrism to ecocentrism: educating for ecological care in health].

PubMed

Backes, Marli Terezinha Stein; Backes, Dirce Stein; Drago, Lívia Crespo; Koerich, Magda Santos; Erdmann, Alacoque Lorenzini

2011-06-01

The focus of the paper is the meaning of ecological care as understood by students and educators and how this issue is addressed in programs in the fields of health sciences and health care in a federal public institution in southern Brazil. Our goal is to discuss the central category. The methodology adopted was Grounded Theory. Ten interviews were carried out among two sample groups between September, 2008, and April, 2009. The results led to the design of the theory: considering ecological care as broad and complex phenomenon, and the core category: the ecological care that results from relations, interactions and associations within the global environment. We concluded that rejecting anthropocentrism is not enough for the survival of all forms of life in the planet. This survival demands educating for ecocentrism and for systemic-functional interactivity and adaptability. We must go beyond speeches and world conferences and redo the web of interdependence of all beings and elements of nature.

Spatial ecological processes and local factors predict the distribution and abundance of spawning by steelhead (Oncorhynchus mykiss) across a complex riverscape

Treesearch

Jeffrey A. Falke; Jason B. Dunham; Christopher E. Jordan; Kristina M. McNyset; Gordon H. Reeves

2013-01-01

Processes that influence habitat selection in landscapes involve the interaction of habitat composition and configuration and are particularly important for species with complex life cycles. We assessed the relative influence of landscape spatial processes and local habitat characteristics on patterns in the distribution and abundance of spawning steelhead (...

A walk on the tundra: Host-parasite interactions in an extreme environment.

PubMed

Kutz, Susan J; Hoberg, Eric P; Molnár, Péter K; Dobson, Andy; Verocai, Guilherme G

2014-08-01

Climate change is occurring very rapidly in the Arctic, and the processes that have taken millions of years to evolve in this very extreme environment are now changing on timescales as short as decades. These changes are dramatic, subtle and non-linear. In this article, we discuss the evolving insights into host-parasite interactions for wild ungulate species, specifically, muskoxen and caribou, in the North American Arctic. These interactions occur in an environment that is characterized by extremes in temperature, high seasonality, and low host species abundance and diversity. We believe that lessons learned in this system can guide wildlife management and conservation throughout the Arctic, and can also be generalized to more broadly understand host-parasite interactions elsewhere. We specifically examine the impacts of climate change on host-parasite interactions and focus on: (I) the direct temperature effects on parasites; (II) the importance of considering the intricacies of host and parasite ecology for anticipating climate change impacts; and (III) the effect of shifting ecological barriers and corridors. Insights gained from studying the history and ecology of host-parasite systems in the Arctic will be central to understanding the role that climate change is playing in these more complex systems.

A walk on the tundra: Host–parasite interactions in an extreme environment

PubMed Central

Kutz, Susan J.; Hoberg, Eric P.; Molnár, Péter K.; Dobson, Andy; Verocai, Guilherme G.

2014-01-01

Climate change is occurring very rapidly in the Arctic, and the processes that have taken millions of years to evolve in this very extreme environment are now changing on timescales as short as decades. These changes are dramatic, subtle and non-linear. In this article, we discuss the evolving insights into host–parasite interactions for wild ungulate species, specifically, muskoxen and caribou, in the North American Arctic. These interactions occur in an environment that is characterized by extremes in temperature, high seasonality, and low host species abundance and diversity. We believe that lessons learned in this system can guide wildlife management and conservation throughout the Arctic, and can also be generalized to more broadly understand host–parasite interactions elsewhere. We specifically examine the impacts of climate change on host–parasite interactions and focus on: (I) the direct temperature effects on parasites; (II) the importance of considering the intricacies of host and parasite ecology for anticipating climate change impacts; and (III) the effect of shifting ecological barriers and corridors. Insights gained from studying the history and ecology of host–parasite systems in the Arctic will be central to understanding the role that climate change is playing in these more complex systems. PMID:25180164

Restoring fish ecological quality in estuaries: Implication of interactive and cumulative effects among anthropogenic stressors.

PubMed

Teichert, Nils; Borja, Angel; Chust, Guillem; Uriarte, Ainhize; Lepage, Mario

2016-01-15

Estuaries are subjected to multiple anthropogenic stressors, which have additive, antagonistic or synergistic effects. Current challenges include the use of large databases of biological monitoring surveys (e.g. the European Water Framework Directive) to help environmental managers prioritizing restoration measures. This study investigated the impact of nine stressor categories on the fish ecological status derived from 90 estuaries of the North East Atlantic countries. We used a random forest model to: 1) detect the dominant stressors and their non-linear effects; 2) evaluate the ecological benefits expected from reducing pressure from stressors; and 3) investigate the interactions among stressors. Results showed that largest restoration benefits were expected when mitigating water pollution and oxygen depletion. Non-additive effects represented half of pairwise interactions among stressors, and antagonisms were the most common. Dredged sediments, flow changes and oxygen depletion were predominantly implicated in non-additive interactions, whereas the remainder stressors often showed additive impacts. The prevalence of interactive impacts reflects a complex scenario for estuaries management; hence, we proposed a step-by-step restoration scheme focusing on the mitigation of stressors providing the maximum of restoration benefits under a multi-stress context. Copyright © 2015 Elsevier B.V. All rights reserved.

Patients as Patches: Ecology and Epidemiology in Healthcare Environments.

PubMed

Lofgren, Eric T; Egizi, Andrea M; Fefferman, Nina H

2016-12-01

The modern healthcare system involves complex interactions among microbes, patients, providers, and the built environment. It represents a unique and challenging setting for control of the emergence and spread of infectious diseases. We examine an extension of the perspectives and methods from ecology (and especially urban ecology) to address these unique issues, and we outline 3 examples: (1) viewing patients as individual microbial ecosystems; (2) the altered ecology of infectious diseases specifically within hospitals; and (3) ecosystem management perspectives for infection surveillance and control. In each of these cases, we explore the accuracy and relevance of analogies to existing urban ecological perspectives, and we demonstrate a few of the potential direct uses of this perspective for altering research into the control of healthcare-associated infections. Infect Control Hosp Epidemiol. 2016;1507-1512.

Application of network methods for understanding evolutionary dynamics in discrete habitats.

PubMed

Greenbaum, Gili; Fefferman, Nina H

2017-06-01

In populations occupying discrete habitat patches, gene flow between habitat patches may form an intricate population structure. In such structures, the evolutionary dynamics resulting from interaction of gene-flow patterns with other evolutionary forces may be exceedingly complex. Several models describing gene flow between discrete habitat patches have been presented in the population-genetics literature; however, these models have usually addressed relatively simple settings of habitable patches and have stopped short of providing general methodologies for addressing nontrivial gene-flow patterns. In the last decades, network theory - a branch of discrete mathematics concerned with complex interactions between discrete elements - has been applied to address several problems in population genetics by modelling gene flow between habitat patches using networks. Here, we present the idea and concepts of modelling complex gene flows in discrete habitats using networks. Our goal is to raise awareness to existing network theory applications in molecular ecology studies, as well as to outline the current and potential contribution of network methods to the understanding of evolutionary dynamics in discrete habitats. We review the main branches of network theory that have been, or that we believe potentially could be, applied to population genetics and molecular ecology research. We address applications to theoretical modelling and to empirical population-genetic studies, and we highlight future directions for extending the integration of network science with molecular ecology. © 2017 John Wiley & Sons Ltd.

Complex adaptive behavior and dexterous action

PubMed Central

Harrison, Steven J.; Stergiou, Nicholas

2016-01-01

Dexterous action, as conceptualized by Bernstein in his influential ecological analysis of human behavior, is revealed in the ability to flexibly generate behaviors that are adaptively tailored to the demands of the context in which they are embedded. Conceived as complex adaptive behavior, dexterity depends upon the qualities of robustness and degeneracy, and is supported by the functional complexity of the agent-environment system. Using Bernstein’s and Gibson’s ecological analyses of behavior situated in natural environments as conceptual touchstones, we consider the hypothesis that complex adaptive behavior capitalizes upon general principles of self-organization. Here, we outline a perspective in which the complex interactivity of nervous-system, body, and environment is revealed as an essential resource for adaptive behavior. From this perspective, we consider the implications for interpreting the functionality and dysfunctionality of human behavior. This paper demonstrates that, optimal variability, the topic of this special issue, is a logical consequence of interpreting the functionality of human behavior as complex adaptive behavior. PMID:26375932

Cross-immunity between strains explains the dynamical pattern of paramyxoviruses

PubMed Central

Bhattacharyya, Samit; Gesteland, Per H.; Korgenski, Kent; Bjørnstad, Ottar N.; Adler, Frederick R.

2015-01-01

Viral respiratory tract diseases pose serious public health problems. Our ability to predict and thus, be able to prepare for outbreaks is strained by the complex factors driving the prevalence and severity of these diseases. The abundance of diseases and transmission dynamics of strains are not only affected by external factors, such as weather, but also driven by interactions among viruses mediated by human behavior and immunity. To untangle the complex out-of-phase annual and biennial pattern of three common paramyxoviruses, Respiratory Syncytial Virus (RSV), Human Parainfluenza Virus (HPIV), and Human Metapneumovirus (hMPV), we adopt a theoretical approach that integrates ecological and immunological mechanisms of disease interactions. By estimating parameters from multiyear time series of laboratory-confirmed cases from the intermountain west region of the United States and using statistical inference, we show that models of immune-mediated interactions better explain the data than those based on ecological competition by convalescence. The strength of cross-protective immunity among viruses is correlated with their genetic distance in the phylogenetic tree of the paramyxovirus family. PMID:26460003

Relationships between soil and leaf mineral composition are element-specific, environment-dependent and geographically structured in the emerging model Arabidopsis halleri.

PubMed

Stein, Ricardo J; Höreth, Stephan; de Melo, J Romário F; Syllwasschy, Lara; Lee, Gwonjin; Garbin, Mário L; Clemens, Stephan; Krämer, Ute

2017-02-01

Leaf mineral composition, the leaf ionome, reflects the complex interaction between a plant and its environment including local soil composition, an influential factor that can limit species distribution and plant productivity. Here we addressed within-species variation in plant-soil interactions and edaphic adaptation using Arabidopsis halleri, a well-suited model species as a facultative metallophyte and metal hyperaccumulator. We conducted multi-element analysis of 1972 paired leaf and soil samples from 165 European populations of A. halleri, at individual resolution to accommodate soil heterogeneity. Results were further confirmed under standardized conditions upon cultivation of 105 field-collected genotypes on an artificially metal-contaminated soil in growth chamber experiments. Soil-independent between- and within-population variation set apart leaf accumulation of zinc, cadmium and lead from all other nutrient and nonessential elements, concurring with differential hypothesized ecological roles in either biotic interaction or nutrition. For these metals, soil-leaf relationships were element-specific, differed between metalliferous and nonmetalliferous soils and were geographically structured both in the field and under standardized growth conditions, implicating complex scenarios of recent ecological adaptation. Our study provides an example and a reference for future related work and will serve as a basis for the molecular-genetic dissection and ecological analysis of the observed phenotypic variation. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Colonization resistance and microbial ecophysiology: using gnotobiotic mouse models and single-cell technology to explore the intestinal jungle.

PubMed

Stecher, Bärbel; Berry, David; Loy, Alexander

2013-09-01

The highly diverse intestinal microbiota forms a structured community engaged in constant communication with itself and its host and is characterized by extensive ecological interactions. A key benefit that the microbiota affords its host is its ability to protect against infections in a process termed colonization resistance (CR), which remains insufficiently understood. In this review, we connect basic concepts of CR with new insights from recent years and highlight key technological advances in the field of microbial ecology. We present a selection of statistical and bioinformatics tools used to generate hypotheses about synergistic and antagonistic interactions in microbial ecosystems from metagenomic datasets. We emphasize the importance of experimentally testing these hypotheses and discuss the value of gnotobiotic mouse models for investigating specific aspects related to microbiota-host-pathogen interactions in a well-defined experimental system. We further introduce new developments in the area of single-cell analysis using fluorescence in situ hybridization in combination with metabolic stable isotope labeling technologies for studying the in vivo activities of complex community members. These approaches promise to yield novel insights into the mechanisms of CR and intestinal ecophysiology in general, and give researchers the means to experimentally test hypotheses in vivo at varying levels of biological and ecological complexity. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Regime shifts and panarchies in regional scale social ...

EPA Pesticide Factsheets

In this article we summarize histories of nonlinear, complex interactions among societal, legal, and ecosystem dynamics in six North American water basins, as they respond to changing climate. These case studies were chosen to explore the conditions for emergence of adaptive governance in heavily regulated and developed social-ecological systems nested within a hierarchical governmental system. We summarize resilience assessments conducted in each system to provide a synthesis and reference by the other articles in this special feature. We also present a general framework used to evaluate the interactions between society and ecosystem regimes and the governance regimes chosen to mediate those interactions. The case studies show different ways that adaptive governance may be triggered, facilitated, or constrained by ecological and/or legal processes. The resilience assessments indicate that complex interactions among the governance and ecosystem components of these systems can produce different trajectories, which include patterns of (a) development and stabilization, (b) cycles of crisis and recovery, which includes lurches in adaptation and learning, and (3) periods of innovation, novelty, and transformation. Exploration of cross scale (Panarchy) interactions among levels and sectors of government and society illustrate that they may constrain development trajectories, but may also provide stability during crisis or innovation at smaller scales; create crises,

Sustainability and Resilience in the Urban Environment

EPA Science Inventory

Urban systems are formed by a diversity of actors and activities, and consist of complex interactions involving financial, information, energy, ecological, and material stocks and flows that operate on different spatial and temporal scales. The urban systems that emerge from thes...

Using HexSim to simulate complex species, landscape, and stressor interactions

EPA Science Inventory

Background / Question / Methods The use of simulation models in conservation biology, landscape ecology, and other disciplines is increasing. Models are essential tools for researchers who, for example, need to forecast future conditions, weigh competing recovery and mitigation...

An integrative model of evolutionary covariance: a symposium on body shape in fishes.

PubMed

Walker, Jeffrey A

2010-12-01

A major direction of current and future biological research is to understand how multiple, interacting functional systems coordinate in producing a body that works. This understanding is complicated by the fact that organisms need to work well in multiple environments, with both predictable and unpredictable environmental perturbations. Furthermore, organismal design reflects a history of past environments and not a plan for future environments. How complex, interacting functional systems evolve, then, is a truly grand challenge. In accepting the challenge, an integrative model of evolutionary covariance is developed. The model combines quantitative genetics, functional morphology/physiology, and functional ecology. The model is used to convene scientists ranging from geneticists, to physiologists, to ecologists, to engineers to facilitate the emergence of body shape in fishes as a model system for understanding how complex, interacting functional systems develop and evolve. Body shape of fish is a complex morphology that (1) results from many developmental paths and (2) functions in many different behaviors. Understanding the coordination and evolution of the many paths from genes to body shape, body shape to function, and function to a working fish body in a dynamic environment is now possible given new technologies from genetics to engineering and new theoretical models that integrate the different levels of biological organization (from genes to ecology).

Ecological, biogeochemical and salinity changes in coastal lakes and wetlands over the last 200 years

NASA Astrophysics Data System (ADS)

Roberts, Lucy; Holmes, Jonathan; Horne, David

2016-04-01

Shallow lakes provide extensive ecosystem services and are ecologically important aquatic resources supporting a diverse flora and fauna. In marginal-marine areas, where such lakes are subjected to the multiple pressures of coastal erosion, sea level rise, increasing sea surface temperature and increasing frequency and intensity of storm surges, environments are complex and unstable. They are characterised by physico-chemical variations due to climatic (precipitation/evaporation cycles) and dynamic factors (tides, currents, freshwater drainage and sea level changes). Combined with human activity in the catchment these processes can alter the salinity, habitat and ecology of coastal fresh- to brackish water ecosystems. In this study the chemical and biological stability of coastal lakes forming the Upper Thurne catchment in the NE of the Norfolk Broads, East Anglia, UK are seriously threatened by long-term changes in salinity resulting from storm surges, complex hydrogeology and anthropogenic activity in the catchment. Future management decisions depend on a sound understanding of the potential ecological impacts, but such understanding is limited by short-term observations and measurements. This research uses palaeolimnological approaches, which can be validated and calibrated with historical records, to reconstruct changes in the aquatic environment on a longer time scale than can be achieved by observations alone. Here, salinity is quantitatively reconstructed using the trace-element geochemistry (Sr/Ca and Mg/Ca) of low Mg-calcite shells of Ostracoda (microscopic bivalved crustaceans) and macrophyte and macroinvertebrate macrofossil remains are used as a proxy to assess ecological change in response to variations in salinity. δ13C values of Cladocera (which are potentially outcompeted by the mysid Neomysis integer with increasing salinity and eutrophication) can be used to reconstruct carbon cycling and energy pathways in lake food webs, which alongside reconstructions of salinity and eutrophication can aid the disentanglement of environmental drivers and increase understanding on the interactions between ecology and biogeochemical cycles within the lake. Previous palaeolimnological work on the Thurne Broads system has suggested shifts between macrophyte abundance and loss within a framework of rising salinity (varying between 1.8-8.7‰ and eutrophication (phosphorus loading greater than 100μg-1). A complex combination of salinity, eutrophication, toxicity and associated changes in habitat have acted as drivers for ecological change over the past 200 years, but these interactions have not previously been well understood. By combining reconstructions of palaeosalinity, biodiversity, food web dynamics, redox conditions and eutrophication, the interaction between and controls on long-term variations in shallow lake environments can be further explored.

Decay of interspecific avian flock networks along a disturbance gradient in Amazonia.

PubMed

Mokross, Karl; Ryder, Thomas B; Côrtes, Marina Corrêa; Wolfe, Jared D; Stouffer, Philip C

2014-02-07

Our understanding of how anthropogenic habitat change shapes species interactions is in its infancy. This is in large part because analytical approaches such as network theory have only recently been applied to characterize complex community dynamics. Network models are a powerful tool for quantifying how ecological interactions are affected by habitat modification because they provide metrics that quantify community structure and function. Here, we examine how large-scale habitat alteration has affected ecological interactions among mixed-species flocking birds in Amazonian rainforest. These flocks provide a model system for investigating how habitat heterogeneity influences non-trophic interactions and the subsequent social structure of forest-dependent mixed-species bird flocks. We analyse 21 flock interaction networks throughout a mosaic of primary forest, fragments of varying sizes and secondary forest (SF) at the Biological Dynamics of Forest Fragments Project in central Amazonian Brazil. Habitat type had a strong effect on network structure at the levels of both species and flock. Frequency of associations among species, as summarized by weighted degree, declined with increasing levels of forest fragmentation and SF. At the flock level, clustering coefficients and overall attendance positively correlated with mean vegetation height, indicating a strong effect of habitat structure on flock cohesion and stability. Prior research has shown that trophic interactions are often resilient to large-scale changes in habitat structure because species are ecologically redundant. By contrast, our results suggest that behavioural interactions and the structure of non-trophic networks are highly sensitive to environmental change. Thus, a more nuanced, system-by-system approach may be needed when thinking about the resiliency of ecological networks.

Deciphering microbial interactions and detecting keystone species with co-occurrence networks.

PubMed

Berry, David; Widder, Stefanie

2014-01-01

Co-occurrence networks produced from microbial survey sequencing data are frequently used to identify interactions between community members. While this approach has potential to reveal ecological processes, it has been insufficiently validated due to the technical limitations inherent in studying complex microbial ecosystems. Here, we simulate multi-species microbial communities with known interaction patterns using generalized Lotka-Volterra dynamics. We then construct co-occurrence networks and evaluate how well networks reveal the underlying interactions and how experimental and ecological parameters can affect network inference and interpretation. We find that co-occurrence networks can recapitulate interaction networks under certain conditions, but that they lose interpretability when the effects of habitat filtering become significant. We demonstrate that networks suffer from local hot spots of spurious correlation in the neighborhood of hub species that engage in many interactions. We also identify topological features associated with keystone species in co-occurrence networks. This study provides a substantiated framework to guide environmental microbiologists in the construction and interpretation of co-occurrence networks from microbial survey datasets.

Ant-Plant Interaction in a Tropical Savanna: May the Network Structure Vary over Time and Influence on the Outcomes of Associations?

PubMed Central

Lange, Denise; Del-Claro, Kleber

2014-01-01

Plant-animal interactions occur in a community context of dynamic and complex ecological interactive networks. The understanding of who interacts with whom is a basic information, but the outcomes of interactions among associates are fundamental to draw valid conclusions about the functional structure of the network. Ecological networks studies in general gave little importance to know the true outcomes of interactions and how they may change over time. We evaluate the dynamic of an interaction network between ants and plants with extrafloral nectaries, by verifying the temporal variation in structure and outcomes of mutualism for the plant community (leaf herbivory). To reach this goal, we used two tools: bipartite network analysis and experimental manipulation. The networks exhibited the same general pattern as other mutualistic networks: nestedness, asymmetry and low specialization and this pattern was maintained over time, but with internal changes (species degree, connectance and ant abundance). These changes influenced the protection effectiveness of plants by ants, which varied over time. Our study shows that interaction networks between ants and plants are dynamic over time, and that these alterations affect the outcomes of mutualisms. In addition, our study proposes that the set of single systems that shape ecological networks can be manipulated for a greater understanding of the entire system. PMID:25141007

Dealing with femtorisks in international relations

PubMed Central

Frank, Aaron Benjamin; Collins, Margaret Goud; Levin, Simon A.; Lo, Andrew W.; Ramo, Joshua; Dieckmann, Ulf; Kremenyuk, Victor; Kryazhimskiy, Arkady; Linnerooth-Bayer, JoAnne; Ramalingam, Ben; Roy, J. Stapleton; Saari, Donald G.; Thurner, Stefan; von Winterfeldt, Detlof

2014-01-01

The contemporary global community is increasingly interdependent and confronted with systemic risks posed by the actions and interactions of actors existing beneath the level of formal institutions, often operating outside effective governance structures. Frequently, these actors are human agents, such as rogue traders or aggressive financial innovators, terrorists, groups of dissidents, or unauthorized sources of sensitive or secret information about government or private sector activities. In other instances, influential “actors” take the form of climate change, communications technologies, or socioeconomic globalization. Although these individual forces may be small relative to state governments or international institutions, or may operate on long time scales, the changes they catalyze can pose significant challenges to the analysis and practice of international relations through the operation of complex feedbacks and interactions of individual agents and interconnected systems. We call these challenges “femtorisks,” and emphasize their importance for two reasons. First, in isolation, they may be inconsequential and semiautonomous; but when embedded in complex adaptive systems, characterized by individual agents able to change, learn from experience, and pursue their own agendas, the strategic interaction between actors can propel systems down paths of increasing, even global, instability. Second, because their influence stems from complex interactions at interfaces of multiple systems (e.g., social, financial, political, technological, ecological, etc.), femtorisks challenge standard approaches to risk assessment, as higher-order consequences cascade across the boundaries of socially constructed complex systems. We argue that new approaches to assessing and managing systemic risk in international relations are required, inspired by principles of evolutionary theory and development of resilient ecological systems. PMID:25404317

Dealing with femtorisks in international relations.

PubMed

Frank, Aaron Benjamin; Collins, Margaret Goud; Levin, Simon A; Lo, Andrew W; Ramo, Joshua; Dieckmann, Ulf; Kremenyuk, Victor; Kryazhimskiy, Arkady; Linnerooth-Bayer, JoAnne; Ramalingam, Ben; Roy, J Stapleton; Saari, Donald G; Thurner, Stefan; von Winterfeldt, Detlof

2014-12-09

The contemporary global community is increasingly interdependent and confronted with systemic risks posed by the actions and interactions of actors existing beneath the level of formal institutions, often operating outside effective governance structures. Frequently, these actors are human agents, such as rogue traders or aggressive financial innovators, terrorists, groups of dissidents, or unauthorized sources of sensitive or secret information about government or private sector activities. In other instances, influential "actors" take the form of climate change, communications technologies, or socioeconomic globalization. Although these individual forces may be small relative to state governments or international institutions, or may operate on long time scales, the changes they catalyze can pose significant challenges to the analysis and practice of international relations through the operation of complex feedbacks and interactions of individual agents and interconnected systems. We call these challenges "femtorisks," and emphasize their importance for two reasons. First, in isolation, they may be inconsequential and semiautonomous; but when embedded in complex adaptive systems, characterized by individual agents able to change, learn from experience, and pursue their own agendas, the strategic interaction between actors can propel systems down paths of increasing, even global, instability. Second, because their influence stems from complex interactions at interfaces of multiple systems (e.g., social, financial, political, technological, ecological, etc.), femtorisks challenge standard approaches to risk assessment, as higher-order consequences cascade across the boundaries of socially constructed complex systems. We argue that new approaches to assessing and managing systemic risk in international relations are required, inspired by principles of evolutionary theory and development of resilient ecological systems.

Ecological Challenges for Closed Systems

NASA Astrophysics Data System (ADS)

Nelson, Mark; Dempster, William; Allen, John P.

2012-07-01

Closed ecological systems are desirable for a number of purposes. In space life support systems, material closure allows precious life-supporting resources to be kept inside and recycled. Closure in small biospheric systems facilitates detailed measurement of global ecological processes and biogeochemical cycles. Closed testbeds facilitate research topics which require isolation from the outside (e.g. genetically modified organisms; radioisotopes) so their ecological interactions and fluxes can be studied separate from interactions with the outside environment. But to achieve and maintain closure entails solving complex ecological challenges. These challenges include being able to handle faster cycling rates and accentuated daily and seasonal fluxes of critical life elements such as carbon dioxide, oxygen, water, macro- and mico-nutrients. The problems of achieving sustainability in closed systems for life support include how to handle atmospheric dynamics including trace gases, producing a complete human diet and recycling nutrients and maintaining soil fertility, the sustaining of healthy air and water and preventing the loss of crucial elements from active circulation. In biospheric facilities the challenge is also to produce analogues to natural biomes and ecosystems, studying processes of self-organization and adaptation in systems that allow specification or determination of state variables and cycles which may be followed through all interactions from atmosphere to soils. Other challenges include the dynamics and genetics of small populations, the psychological challenges for small isolated human groups and measures and options which may be necessary to ensure long-term operation of closed ecological systems.

Key ecological challenges for closed systems facilities

NASA Astrophysics Data System (ADS)

Nelson, Mark; Dempster, William F.; Allen, John P.

2013-07-01

Closed ecological systems are desirable for a number of purposes. In space life support systems, material closure allows precious life-supporting resources to be kept inside and recycled. Closure in small biospheric systems facilitates detailed measurement of global ecological processes and biogeochemical cycles. Closed testbeds facilitate research topics which require isolation from the outside (e.g. genetically modified organisms; radioisotopes) so their ecological interactions and fluxes can be studied separate from interactions with the outside environment. But to achieve and maintain closure entails solving complex ecological challenges. These challenges include being able to handle faster cycling rates and accentuated daily and seasonal fluxes of critical life elements such as carbon dioxide, oxygen, water, macro- and mico-nutrients. The problems of achieving sustainability in closed systems for life support include how to handle atmospheric dynamics including trace gases, producing a complete human diet, recycling nutrients and maintaining soil fertility, the maintenance of healthy air and water and preventing the loss of critical elements from active circulation. In biospheric facilities, the challenge is also to produce analogues to natural biomes and ecosystems, studying processes of self-organization and adaptation in systems that allow specification or determination of state variables and cycles which may be followed through all interactions from atmosphere to soils. Other challenges include the dynamics and genetics of small populations, the psychological challenges for small isolated human groups and backup technologies and strategic options which may be necessary to ensure long-term operation of closed ecological systems.

Intrinsic incompatibilities evolving as a by-product of divergent ecological selection: Considering them in empirical studies on divergence with gene flow.

PubMed

Kulmuni, J; Westram, A M

2017-06-01

The possibility of intrinsic barriers to gene flow is often neglected in empirical research on local adaptation and speciation with gene flow, for example when interpreting patterns observed in genome scans. However, we draw attention to the fact that, even with gene flow, divergent ecological selection may generate intrinsic barriers involving both ecologically selected and other interacting loci. Mechanistically, the link between the two types of barriers may be generated by genes that have multiple functions (i.e., pleiotropy), and/or by gene interaction networks. Because most genes function in complex networks, and their evolution is not independent of other genes, changes evolving in response to ecological selection can generate intrinsic barriers as a by-product. A crucial question is to what extent such by-product barriers contribute to divergence and speciation-that is whether they stably reduce gene flow. We discuss under which conditions by-product barriers may increase isolation. However, we also highlight that, depending on the conditions (e.g., the amount of gene flow and the strength of selection acting on the intrinsic vs. the ecological barrier component), the intrinsic incompatibility may actually destabilize barriers to gene flow. In practice, intrinsic barriers generated as a by-product of divergent ecological selection may generate peaks in genome scans that cannot easily be interpreted. We argue that empirical studies on divergence with gene flow should consider the possibility of both ecological and intrinsic barriers. Future progress will likely come from work combining population genomic studies, experiments quantifying fitness and molecular studies on protein function and interactions. © 2017 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Reconnecting cities to the biosphere: stewardship of green infrastructure and urban ecosystem services.

PubMed

Andersson, Erik; Barthel, Stephan; Borgström, Sara; Colding, Johan; Elmqvist, Thomas; Folke, Carl; Gren, Åsa

2014-05-01

Within-city green infrastructure can offer opportunities and new contexts for people to become stewards of ecosystem services. We analyze cities as social-ecological systems, synthesize the literature, and provide examples from more than 15 years of research in the Stockholm urban region, Sweden. The social-ecological approach spans from investigating ecosystem properties to the social frameworks and personal values that drive and shape human interactions with nature. Key findings demonstrate that urban ecosystem services are generated by social-ecological systems and that local stewards are critically important. However, land-use planning and management seldom account for their role in the generation of urban ecosystem services. While the small scale patchwork of land uses in cities stimulates intense interactions across borders much focus is still on individual patches. The results highlight the importance and complexity of stewardship of urban biodiversity and ecosystem services and of the planning and governance of urban green infrastructure.

Ecological community integration increases with added trophic complexity

USGS Publications Warehouse

Wright, Christopher K.

2008-01-01

The existence of functional biological organization at the level of multi-species communities has long been contested in ecology and evolutionary biology. I found that adding a trophic level to simulated ecological communities enhanced their ability to compete at the community level, increasing the likelihood of one community forcing all or most species in a second community to extinction. Community-level identity emerged within systems of interacting ecological networks, while competitive ability at the community level was enhanced by intense within-community selection pressure. These results suggest a reassessment of the nature of biological organization above the level of species, indicating that the drive toward biological integration, so prominent throughout the history of life, might extend to multi-species communities.

"Crown of thorns" of Daphnia: an exceptional inducible defense discovered by DNA barcoding.

PubMed

Laforsch, Christian; Haas, Andreas; Jung, Nina; Schwenk, Klaus; Tollrian, Ralph; Petrusek, Adam

2009-09-01

DNA barcoding has emerged as valuable tool to document global biodiversity. Mitochondrial cytochrome oxidase I (COI) sequences serve as genetic markers to catalogue species richness in the animal kingdom and to identify cryptic and polymorphic animal species. Furthermore, DNA barcoding data serve as a fuel for ecological studies, as they provide the opportunity to unravel species interactions among hosts and parasites, predators and prey, and among competitors in unprecedented detail. In a recent paper we described how DNA barcoding in combination with morphological and ecological data unravelled a striking predator-prey interaction of organisms from temporary aquatic habitats, the predatory notostracan Triops and its prey, cladocerans of the Daphnia atkinsoni complex.

Multidimensional approaches for studying plant defence against insects: from ecology to omics and synthetic biology.

PubMed

Barah, Pankaj; Bones, Atle M

2015-02-01

The biggest challenge for modern biology is to integrate multidisciplinary approaches towards understanding the organizational and functional complexity of biological systems at different hierarchies, starting from the subcellular molecular mechanisms (microscopic) to the functional interactions of ecological communities (macroscopic). The plant-insect interaction is a good model for this purpose with the availability of an enormous amount of information at the molecular and the ecosystem levels. Changing global climatic conditions are abruptly resetting plant-insect interactions. Integration of discretely located heterogeneous information from the ecosystem to genes and pathways will be an advantage to understand the complexity of plant-insect interactions. This review will present the recent developments in omics-based high-throughput experimental approaches, with particular emphasis on studying plant defence responses against insect attack. The review highlights the importance of using integrative systems approaches to study plant-insect interactions from the macroscopic to the microscopic level. We analyse the current efforts in generating, integrating and modelling multiomics data to understand plant-insect interaction at a systems level. As a future prospect, we highlight the growing interest in utilizing the synthetic biology platform for engineering insect-resistant plants. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Meeting the challenge of interacting threats in freshwater ecosystems: A call to scientists and managers

USGS Publications Warehouse

Craig, Laura S.; Olden, Julian D.; Arthington, Angela; Entrekin, Sally; Hawkins, Charles P.; Kelly, John J.; Kennedy, Theodore A.; Maitland, Bryan M.; Rosi, Emma J.; Roy, Allison; Strayer, David L.; Tank, Jennifer L.; West, Amie O.; Wooten, Matthew S.

2017-01-01

Human activities create threats that have consequences for freshwater ecosystems and, in most watersheds, observed ecological responses are the result of complex interactions among multiple threats and their associated ecological alterations. Here we discuss the value of considering multiple threats in research and management, offer suggestions for filling knowledge gaps, and provide guidance for addressing the urgent management challenges posed by multiple threats in freshwater ecosystems. There is a growing literature assessing responses to multiple alterations, and we build off this background to identify three areas that require greater attention: linking observed alterations to threats, understanding when and where threats overlap, and choosing metrics that best quantify the effects of multiple threats. Advancing science in these areas will help us understand existing ecosystem conditions and predict future risk from multiple threats. Because addressing the complex issues and novel ecosystems that arise from the interaction of multiple threats in freshwater ecosystems represents a significant management challenge, and the risks of management failure include loss of biodiversity, ecological goods, and ecosystem services, we also identify actions that could improve decision-making and management outcomes. These actions include drawing insights from management of individual threats, using threat attributes (e.g., causes and spatio-temporal dynamics) to identify suitable management approaches, testing management strategies that are likely to be successful despite uncertainties about the nature of interactions among threats, avoiding unintended consequences, and maximizing conservation benefits. We also acknowledge the broadly applicable challenges of decision-making within a socio-political and economic framework, and suggest that multidisciplinary teams will be needed to innovate solutions to meet the current and future challenge of interacting threats in freshwater ecosystems. 

Integrating research tools to support the management of social-ecological systems under climate change

USGS Publications Warehouse

Miller, Brian W.; Morisette, Jeffrey T.

2014-01-01

Developing resource management strategies in the face of climate change is complicated by the considerable uncertainty associated with projections of climate and its impacts and by the complex interactions between social and ecological variables. The broad, interconnected nature of this challenge has resulted in calls for analytical frameworks that integrate research tools and can support natural resource management decision making in the face of uncertainty and complex interactions. We respond to this call by first reviewing three methods that have proven useful for climate change research, but whose application and development have been largely isolated: species distribution modeling, scenario planning, and simulation modeling. Species distribution models provide data-driven estimates of the future distributions of species of interest, but they face several limitations and their output alone is not sufficient to guide complex decisions for how best to manage resources given social and economic considerations along with dynamic and uncertain future conditions. Researchers and managers are increasingly exploring potential futures of social-ecological systems through scenario planning, but this process often lacks quantitative response modeling and validation procedures. Simulation models are well placed to provide added rigor to scenario planning because of their ability to reproduce complex system dynamics, but the scenarios and management options explored in simulations are often not developed by stakeholders, and there is not a clear consensus on how to include climate model outputs. We see these strengths and weaknesses as complementarities and offer an analytical framework for integrating these three tools. We then describe the ways in which this framework can help shift climate change research from useful to usable.

Wildfire and forest disease interaction lead to greater loss of soil nutrients and carbon

Treesearch

Richard C. Cobb; Ross K. Meentemeyer; David M. Rizzo

2016-01-01

Fire and forest disease have significant ecological impacts, but the interactions of these two disturbances are rarely studied. We measured soil C, N, Ca, P, and pH in forests of the Big Sur region of California impacted by the exotic pathogen Phytophthora ramorum, cause of sudden oak death, and the 2008 Basin wildfire complex. In Big Sur,...

Integrating ecological risk assessments across levels of organization using the Franklin-Noss model of biodiversity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brugger, K.E.; Tiebout, H.M. III

1994-12-31

Wildlife toxicologists pioneered methodologies for assessing ecological risk to nontarget species. Historically, ecological risk assessments (ERAS) focused on a limited array of species and were based on a relatively few population-level endpoints (mortality, reproduction). Currently, risk assessment models are becoming increasingly complex that factor in multi-species interactions (across trophic levels) and utilize an increasingly diverse number of ecologically significant endpoints. This trend suggests the increasing importance of safeguarding not only populations of individual species, but also the overall integrity of the larger biotic systems that support them. In this sense, ERAs are in alignment with Conservation Biology, an applied sciencemore » of ecological knowledge used to conserve biodiversity. A theoretical conservation biology model could be incorporated in ERAs to quantify impacts to biodiversity (structure, function or composition across levels of biological organization). The authors suggest that the Franklin-Noss model for evaluating biodiversity, with its nested, hierarchical approach, may provide a suitable paradigm for assessing and integrating the ecological risk that chemical contaminants pose to biological systems from the simplest levels (genotypes, individual organisms) to the most complex levels of organization (communities and ecosystems). The Franklin-Noss model can accommodate the existing ecotoxicological database and, perhaps more importantly, indicate new areas in which critical endpoints should be identified and investigated.« less

Stabilization of Large Generalized Lotka-Volterra Foodwebs By Evolutionary Feedback

NASA Astrophysics Data System (ADS)

Ackland, G. J.; Gallagher, I. D.

2004-10-01

Conventional ecological models show that complexity destabilizes foodwebs, suggesting that foodwebs should have neither large numbers of species nor a large number of interactions. However, in nature the opposite appears to be the case. Here we show that if the interactions between species are allowed to evolve within a generalized Lotka-Volterra model such stabilizing feedbacks and weak interactions emerge automatically. Moreover, we show that trophic levels also emerge spontaneously from the evolutionary approach, and the efficiency of the unperturbed ecosystem increases with time. The key to stability in large foodwebs appears to arise not from complexity perse but from evolution at the level of the ecosystem which favors stabilizing (negative) feedbacks.

Stabilization of large generalized Lotka-Volterra foodwebs by evolutionary feedback.

PubMed

Ackland, G J; Gallagher, I D

2004-10-08

Conventional ecological models show that complexity destabilizes foodwebs, suggesting that foodwebs should have neither large numbers of species nor a large number of interactions. However, in nature the opposite appears to be the case. Here we show that if the interactions between species are allowed to evolve within a generalized Lotka-Volterra model such stabilizing feedbacks and weak interactions emerge automatically. Moreover, we show that trophic levels also emerge spontaneously from the evolutionary approach, and the efficiency of the unperturbed ecosystem increases with time. The key to stability in large foodwebs appears to arise not from complexity per se but from evolution at the level of the ecosystem which favors stabilizing (negative) feedbacks.

Resilience and challenges of marine social-ecological systems under complex and interconnected drivers.

PubMed

Villasante, Sebastián; Macho, Gonzalo; Antelo, Manel; Rodríguez-González, David; Kaiser, Michel J

2013-12-01

In this paper, we summarize the contributions made by an interdisciplinary group of researchers from different disciplines (biology, ecology, economics, and law) that deal with key dimensions of marine social-ecological systems. Particularly, the local and global seafood provision; the feasibility and management of marine protected areas; the use of marine ecosystem services; the institutional dimension in European fisheries, and the affordable models for providing scientific advice to small-scale fisheries. This Special Issue presents key findings from selected case studies around the world available to educators, policy makers, and the technical community. Together, these papers show that a range of diverse ecological, economic, social, and institutional components often mutually interact at spatial and temporal scales, which evidence that managing marine social-ecological systems needs a continuous adaptability to navigate into new governance systems.

Defining the Core Microbiome in Corals' Microbial Soup.

PubMed

Hernandez-Agreda, Alejandra; Gates, Ruth D; Ainsworth, Tracy D

2017-02-01

Corals are considered one of the most complex microbial biospheres studied to date, hosting thousands of bacterial phylotypes in species-specific associations. There are, however, substantial knowledge gaps and challenges in understanding the functional significance of bacterial communities and bacterial symbioses of corals. The ubiquitous nature of some bacterial interactions has only recently been investigated and an accurate differentiation between the healthy (symbiotic) and unhealthy (dysbiotic) microbial state has not yet been determined. Here we review the complexity of the coral holobiont, coral microbiome diversity, and recently proposed bacterial symbioses of corals. We provide insight into coupling the core microbiome framework with community ecology principals, and draw on the theoretical insights from other complex systems, to build a framework to aid in deciphering ecologically significant microbes within a corals' microbial soup. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reconceptualizing synergism and antagonism among multiple stressors.

PubMed

Piggott, Jeremy J; Townsend, Colin R; Matthaei, Christoph D

2015-04-01

The potential for complex synergistic or antagonistic interactions between multiple stressors presents one of the largest uncertainties when predicting ecological change but, despite common use of the terms in the scientific literature, a consensus on their operational definition is still lacking. The identification of synergism or antagonism is generally straightforward when stressors operate in the same direction, but if individual stressor effects oppose each other, the definition of synergism is paradoxical because what is synergistic to one stressor's effect direction is antagonistic to the others. In their highly cited meta-analysis, Crain et al. (Ecology Letters, 11, 2008: 1304) assumed in situations with opposing individual effects that synergy only occurs when the cumulative effect is more negative than the additive sum of the opposing individual effects. We argue against this and propose a new systematic classification based on an additive effects model that combines the magnitude and response direction of the cumulative effect and the interaction effect. A new class of "mitigating synergism" is identified, where cumulative effects are reversed and enhanced. We applied our directional classification to the dataset compiled by Crain et al. (Ecology Letters, 11, 2008: 1304) to determine the prevalence of synergistic, antagonistic, and additive interactions. Compared to their original analysis, we report differences in the representation of interaction classes by interaction type and we document examples of mitigating synergism, highlighting the importance of incorporating individual stressor effect directions in the determination of synergisms and antagonisms. This is particularly pertinent given a general bias in ecology toward investigating and reporting adverse multiple stressor effects (double negative). We emphasize the need for reconsideration by the ecological community of the interpretation of synergism and antagonism in situations where individual stressor effects oppose each other or where cumulative effects are reversed and enhanced.

Cooperation and coexpression: How coexpression networks shift in response to multiple mutualists.

PubMed

Palakurty, Sathvik X; Stinchcombe, John R; Afkhami, Michelle E

2018-04-01

A mechanistic understanding of community ecology requires tackling the nonadditive effects of multispecies interactions, a challenge that necessitates integration of ecological and molecular complexity-namely moving beyond pairwise ecological interaction studies and the "gene at a time" approach to mechanism. Here, we investigate the consequences of multispecies mutualisms for the structure and function of genomewide differential coexpression networks for the first time, using the tractable and ecologically important interaction between legume Medicago truncatula, rhizobia and mycorrhizal fungi. First, we found that genes whose expression is affected nonadditively by multiple mutualists are more highly connected in gene networks than expected by chance and had 94% greater network centrality than genes showing additive effects, suggesting that nonadditive genes may be key players in the widespread transcriptomic responses to multispecies symbioses. Second, multispecies mutualisms substantially changed coexpression network structure of 18 modules of host plant genes and 22 modules of the fungal symbionts' genes, indicating that third-party mutualists can cause significant rewiring of plant and fungal molecular networks. Third, we found that 60% of the coexpressed gene sets that explained variation in plant performance had coexpression structures that were altered by interactive effects of rhizobia and fungi. Finally, an "across-symbiosis" approach identified sets of plant and mycorrhizal genes whose coexpression structure was unique to the multiple mutualist context and suggested coupled responses across the plant-mycorrhizal interaction to rhizobial mutualists. Taken together, these results show multispecies mutualisms have substantial effects on the molecular interactions in host plants, microbes and across symbiotic boundaries. © 2018 John Wiley & Sons Ltd.

Ecological Patterns Among Bacteria and Microbial Eukaryotes Derived from Network Analyses in a Low-Salinity Lake.

PubMed

Jones, Adriane Clark; Hambright, K David; Caron, David A

2018-05-01

Microbial communities are comprised of complex assemblages of highly interactive taxa. We employed network analyses to identify and describe microbial interactions and co-occurrence patterns between microbial eukaryotes and bacteria at two locations within a low salinity (0.5-3.5 ppt) lake over an annual cycle. We previously documented that the microbial diversity and community composition within Lake Texoma, southwest USA, were significantly affected by both seasonal forces and a site-specific bloom of the harmful alga, Prymnesium parvum. We used network analyses to answer ecological questions involving both the bacterial and microbial eukaryotic datasets and to infer ecological relationships within the microbial communities. Patterns of connectivity at both locations reflected the seasonality of the lake including a large rain disturbance in May, while a comparison of the communities between locations revealed a localized response to the algal bloom. A network built from shared nodes (microbial operational taxonomic units and environmental variables) and correlations identified conserved associations at both locations within the lake. Using network analyses, we were able to detect disturbance events, characterize the ecological extent of a harmful algal bloom, and infer ecological relationships not apparent from diversity statistics alone.

Applying Movement Ecology to Marine Animals with Complex Life Cycles.

PubMed

Allen, Richard M; Metaxas, Anna; Snelgrove, Paul V R

2018-01-03

Marine animals with complex life cycles may move passively or actively for fertilization, dispersal, predator avoidance, resource acquisition, and migration, and over scales from micrometers to thousands of kilometers. This diversity has catalyzed idiosyncratic and unfocused research, creating unsound paradigms regarding the role of movement in ecology and evolution. The emerging movement ecology paradigm offers a framework to consolidate movement research independent of taxon, life-history stage, scale, or discipline. This review applies the framework to movement among life-history stages in marine animals with complex life cycles to consolidate marine movement research and offer insights for scientists working in aquatic and terrestrial realms. Irrespective of data collection or simulation strategy, breaking each life-history stage down into the fundamental units of movement allows each unit to be studied independently or interactively with other units. Understanding these underlying mechanisms of movement within each life-history stage can then be used to construct lifetime movement paths. These paths can allow further investigation of the relative contributions and interdependencies of steps and phases across a lifetime and how these paths influence larger research topics, such as population-level movements.

Applying Movement Ecology to Marine Animals with Complex Life Cycles

NASA Astrophysics Data System (ADS)

Allen, Richard M.; Metaxas, Anna; Snelgrove, Paul V. R.

2018-01-01

Marine animals with complex life cycles may move passively or actively for fertilization, dispersal, predator avoidance, resource acquisition, and migration, and over scales from micrometers to thousands of kilometers. This diversity has catalyzed idiosyncratic and unfocused research, creating unsound paradigms regarding the role of movement in ecology and evolution. The emerging movement ecology paradigm offers a framework to consolidate movement research independent of taxon, life-history stage, scale, or discipline. This review applies the framework to movement among life-history stages in marine animals with complex life cycles to consolidate marine movement research and offer insights for scientists working in aquatic and terrestrial realms. Irrespective of data collection or simulation strategy, breaking each life-history stage down into the fundamental units of movement allows each unit to be studied independently or interactively with other units. Understanding these underlying mechanisms of movement within each life-history stage can then be used to construct lifetime movement paths. These paths can allow further investigation of the relative contributions and interdependencies of steps and phases across a lifetime and how these paths influence larger research topics, such as population-level movements.

Combining Costs and Benefits of Animal Activities to Assess Net Yield Outcomes in Apple Orchards

PubMed Central

Luck, Gary W.

2016-01-01

Diverse animal communities influence ecosystem function in agroecosystems through positive and negative plant-animal interactions. Yet, past research has largely failed to examine multiple interactions that can have opposing impacts on agricultural production in a given context. We collected data on arthropod communities and yield quality and quantity parameters (fruit set, yield loss and net outcomes) in three major apple-growing regions in south-eastern Australia. We quantified the net yield outcome (accounting for positive and negative interactions) of multiple animal activities (pollination, fruit damage, biological control) across the entire growing season on netted branches, which excluded vertebrate predators of arthropods, and open branches. Net outcome was calculated as the number of undamaged fruit at harvest as a proportion of the number of blossoms (i.e., potential fruit yield). Vertebrate exclusion resulted in lower levels of fruit set and higher levels of arthropod damage to apples, but did not affect net outcomes. Yield quality and quantity parameters (fruit set, yield loss, net outcomes) were not directly associated with arthropod functional groups. Model variance and significant differences between the ratio of pest to beneficial arthropods between regions indicated that complex relationships between environmental factors and multiple animal interactions have a combined effect on yield. Our results show that focusing on a single crop stage, species group or ecosystem function/service can overlook important complexity in ecological processes within the system. Accounting for this complexity and quantifying the net outcome of ecological interactions within the system, is more informative for research and management of biodiversity and ecosystem services in agricultural landscapes. PMID:27391022

Combining Costs and Benefits of Animal Activities to Assess Net Yield Outcomes in Apple Orchards.

PubMed

Saunders, Manu E; Luck, Gary W

2016-01-01

Diverse animal communities influence ecosystem function in agroecosystems through positive and negative plant-animal interactions. Yet, past research has largely failed to examine multiple interactions that can have opposing impacts on agricultural production in a given context. We collected data on arthropod communities and yield quality and quantity parameters (fruit set, yield loss and net outcomes) in three major apple-growing regions in south-eastern Australia. We quantified the net yield outcome (accounting for positive and negative interactions) of multiple animal activities (pollination, fruit damage, biological control) across the entire growing season on netted branches, which excluded vertebrate predators of arthropods, and open branches. Net outcome was calculated as the number of undamaged fruit at harvest as a proportion of the number of blossoms (i.e., potential fruit yield). Vertebrate exclusion resulted in lower levels of fruit set and higher levels of arthropod damage to apples, but did not affect net outcomes. Yield quality and quantity parameters (fruit set, yield loss, net outcomes) were not directly associated with arthropod functional groups. Model variance and significant differences between the ratio of pest to beneficial arthropods between regions indicated that complex relationships between environmental factors and multiple animal interactions have a combined effect on yield. Our results show that focusing on a single crop stage, species group or ecosystem function/service can overlook important complexity in ecological processes within the system. Accounting for this complexity and quantifying the net outcome of ecological interactions within the system, is more informative for research and management of biodiversity and ecosystem services in agricultural landscapes.

The Role of Model Complexity in Determining Patterns of Chlorophyll Variability in the Coastal Northwest North Atlantic

NASA Astrophysics Data System (ADS)

Kuhn, A. M.; Fennel, K.; Bianucci, L.

2016-02-01

A key feature of the North Atlantic Ocean's biological dynamics is the annual phytoplankton spring bloom. In the region comprising the continental shelf and adjacent deep ocean of the northwest North Atlantic, we identified two patterns of bloom development: 1) locations with cold temperatures and deep winter mixed layers, where the spring bloom peaks around April and the annual chlorophyll cycle has a large amplitude, and 2) locations with warmer temperatures and shallow winter mixed layers, where the spring bloom peaks earlier in the year, sometimes indiscernible from the fall bloom. These patterns result from a combination of limiting environmental factors and interactions among planktonic groups with different optimal requirements. Simple models that represent the ecosystem with a single phytoplankton (P) and a single zooplankton (Z) group are challenged to reproduce these ecological interactions. Here we investigate the effect that added complexity has on determining spatio-temporal chlorophyll. We compare two ecosystem models, one that contains one P and one Z group, and one with two P and three Z groups. We consider three types of changes in complexity: 1) added dependencies among variables (e.g., temperature dependent rates), 2) modified structural pathways, and 3) added pathways. Subsets of the most sensitive parameters are optimized in each model to replicate observations in the region. For computational efficiency, the parameter optimization is performed using 1D surrogates of a 3D model. We evaluate how model complexity affects model skill, and whether the optimized parameter sets found for each model modify the interpretation of ecosystem functioning. Spatial differences in the parameter sets that best represent different areas hint at the existence of different ecological communities or at physical-biological interactions that are not represented in the simplest model. Our methodology emphasizes the combined use of observations, 1D models to help identifying patterns, and 3D models able to simulate the environment modre realistically, as a means to acquire predictive understanding of the ocean's ecology.

Regime shifts and panarchies in regional scale social-ecological water systems

EPA Science Inventory

In this article we summarize histories of nonlinear, complex interactions among societal, legal, and ecosystem dynamics in six North American water basins, as they respond to changing climate. These case studies were chosen to explore the conditions for emergence of adaptive gove...

Hydrological modeling of upper Indus Basin and assessment of deltaic ecology

USDA-ARS?s Scientific Manuscript database

Managing water resources is mostly required at watershed scale where the complex hydrology processes and interactions linking land surface, climatic factors and human activities can be studied. Geographical Information System based watershed model; Soil and Water Assessment Tool (SWAT) is applied f...

Climate Change, Nutrition, and Bottom-Up and Top-Down Food Web Processes.

PubMed

Rosenblatt, Adam E; Schmitz, Oswald J

2016-12-01

Climate change ecology has focused on climate effects on trophic interactions through the lenses of temperature effects on organismal physiology and phenological asynchronies. Trophic interactions are also affected by the nutrient content of resources, but this topic has received less attention. Using concepts from nutritional ecology, we propose a conceptual framework for understanding how climate affects food webs through top-down and bottom-up processes impacted by co-occurring environmental drivers. The framework integrates climate effects on consumer physiology and feeding behavior with effects on resource nutrient content. It illustrates how studying responses of simplified food webs to simplified climate change might produce erroneous predictions. We encourage greater integrative complexity of climate change research on trophic interactions to resolve patterns and enhance predictive capacities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Detection of time delays and directional interactions based on time series from complex dynamical systems

NASA Astrophysics Data System (ADS)

Ma, Huanfei; Leng, Siyang; Tao, Chenyang; Ying, Xiong; Kurths, Jürgen; Lai, Ying-Cheng; Lin, Wei

2017-07-01

Data-based and model-free accurate identification of intrinsic time delays and directional interactions is an extremely challenging problem in complex dynamical systems and their networks reconstruction. A model-free method with new scores is proposed to be generally capable of detecting single, multiple, and distributed time delays. The method is applicable not only to mutually interacting dynamical variables but also to self-interacting variables in a time-delayed feedback loop. Validation of the method is carried out using physical, biological, and ecological models and real data sets. Especially, applying the method to air pollution data and hospital admission records of cardiovascular diseases in Hong Kong reveals the major air pollutants as a cause of the diseases and, more importantly, it uncovers a hidden time delay (about 30-40 days) in the causal influence that previous studies failed to detect. The proposed method is expected to be universally applicable to ascertaining and quantifying subtle interactions (e.g., causation) in complex systems arising from a broad range of disciplines.

Predator and prey functional traits: understanding the adaptive machinery driving predator–prey interactions

PubMed Central

Schmitz, Oswald

2017-01-01

Predator–prey relationships are a central component of community dynamics. Classic approaches have tried to understand and predict these relationships in terms of consumptive interactions between predator and prey species, but characterizing the interaction this way is insufficient to predict the complexity and context dependency inherent in predator–prey relationships. Recent approaches have begun to explore predator–prey relationships in terms of an evolutionary-ecological game in which predator and prey adapt to each other through reciprocal interactions involving context-dependent expression of functional traits that influence their biomechanics. Functional traits are defined as any morphological, behavioral, or physiological trait of an organism associated with a biotic interaction. Such traits include predator and prey body size, predator and prey personality, predator hunting mode, prey mobility, prey anti-predator behavior, and prey physiological stress. Here, I discuss recent advances in this functional trait approach. Evidence shows that the nature and strength of many interactions are dependent upon the relative magnitude of predator and prey functional traits. Moreover, trait responses can be triggered by non-consumptive predator–prey interactions elicited by responses of prey to risk of predation. These interactions in turn can have dynamic feedbacks that can change the context of the predator–prey interaction, causing predator and prey to adapt their traits—through phenotypically plastic or rapid evolutionary responses—and the nature of their interaction. Research shows that examining predator–prey interactions through the lens of an adaptive evolutionary-ecological game offers a foundation to explain variety in the nature and strength of predator–prey interactions observed in different ecological contexts. PMID:29043073

Predator and prey functional traits: understanding the adaptive machinery driving predator-prey interactions.

PubMed

Schmitz, Oswald

2017-01-01

Predator-prey relationships are a central component of community dynamics. Classic approaches have tried to understand and predict these relationships in terms of consumptive interactions between predator and prey species, but characterizing the interaction this way is insufficient to predict the complexity and context dependency inherent in predator-prey relationships. Recent approaches have begun to explore predator-prey relationships in terms of an evolutionary-ecological game in which predator and prey adapt to each other through reciprocal interactions involving context-dependent expression of functional traits that influence their biomechanics. Functional traits are defined as any morphological, behavioral, or physiological trait of an organism associated with a biotic interaction. Such traits include predator and prey body size, predator and prey personality, predator hunting mode, prey mobility, prey anti-predator behavior, and prey physiological stress. Here, I discuss recent advances in this functional trait approach. Evidence shows that the nature and strength of many interactions are dependent upon the relative magnitude of predator and prey functional traits. Moreover, trait responses can be triggered by non-consumptive predator-prey interactions elicited by responses of prey to risk of predation. These interactions in turn can have dynamic feedbacks that can change the context of the predator-prey interaction, causing predator and prey to adapt their traits-through phenotypically plastic or rapid evolutionary responses-and the nature of their interaction. Research shows that examining predator-prey interactions through the lens of an adaptive evolutionary-ecological game offers a foundation to explain variety in the nature and strength of predator-prey interactions observed in different ecological contexts.

Describing and understanding behavioral responses to multiple stressors and multiple stimuli.

PubMed

Hale, Robin; Piggott, Jeremy J; Swearer, Stephen E

2017-01-01

Understanding the effects of environmental change on natural ecosystems is a major challenge, particularly when multiple stressors interact to produce unexpected "ecological surprises" in the form of complex, nonadditive effects that can amplify or reduce their individual effects. Animals often respond behaviorally to environmental change, and multiple stressors can have both population-level and community-level effects. However, the individual, not combined, effects of stressors on animal behavior are commonly studied. There is a need to understand how animals respond to the more complex combinations of stressors that occur in nature, which requires a systematic and rigorous approach to quantify the various potential behavioral responses to the independent and interactive effects of stressors. We illustrate a robust, systematic approach for understanding behavioral responses to multiple stressors based on integrating schemes used to quantitatively classify interactions in multiple-stressor research and to qualitatively view interactions between multiple stimuli in behavioral experiments. We introduce and unify the two frameworks, highlighting their conceptual and methodological similarities, and use four case studies to demonstrate how this unification could improve our interpretation of interactions in behavioral experiments and guide efforts to manage the effects of multiple stressors. Our unified approach: (1) provides behavioral ecologists with a more rigorous and systematic way to quantify how animals respond to interactions between multiple stimuli, an important theoretical advance, (2) helps us better understand how animals behave when they encounter multiple, potentially interacting stressors, and (3) contributes more generally to the understanding of "ecological surprises" in multiple stressors research.

Animal behaviour shapes the ecological effects of ocean acidification and warming: moving from individual to community-level responses.

PubMed

Nagelkerken, Ivan; Munday, Philip L

2016-03-01

Biological communities are shaped by complex interactions between organisms and their environment as well as interactions with other species. Humans are rapidly changing the marine environment through increasing greenhouse gas emissions, resulting in ocean warming and acidification. The first response by animals to environmental change is predominantly through modification of their behaviour, which in turn affects species interactions and ecological processes. Yet, many climate change studies ignore animal behaviour. Furthermore, our current knowledge of how global change alters animal behaviour is mostly restricted to single species, life phases and stressors, leading to an incomplete view of how coinciding climate stressors can affect the ecological interactions that structure biological communities. Here, we first review studies on the effects of warming and acidification on the behaviour of marine animals. We demonstrate how pervasive the effects of global change are on a wide range of critical behaviours that determine the persistence of species and their success in ecological communities. We then evaluate several approaches to studying the ecological effects of warming and acidification, and identify knowledge gaps that need to be filled, to better understand how global change will affect marine populations and communities through altered animal behaviours. Our review provides a synthesis of the far-reaching consequences that behavioural changes could have for marine ecosystems in a rapidly changing environment. Without considering the pervasive effects of climate change on animal behaviour we will limit our ability to forecast the impacts of ocean change and provide insights that can aid management strategies. © 2015 John Wiley & Sons Ltd.

What can music tell us about social interaction?

PubMed

D'Ausilio, Alessandro; Novembre, Giacomo; Fadiga, Luciano; Keller, Peter E

2015-03-01

Humans are innately social creatures, but cognitive neuroscience, that has traditionally focused on individual brains, is only now beginning to investigate social cognition through realistic interpersonal interaction. Music provides an ideal domain for doing so because it offers a promising solution for balancing the trade-off between ecological validity and experimental control when testing cognitive and brain functions. Musical ensembles constitute a microcosm that provides a platform for parametrically modeling the complexity of human social interaction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Morphological similarity and ecological overlap in two rotifer species.

PubMed

Gabaldón, Carmen; Montero-Pau, Javier; Serra, Manuel; Carmona, María José

2013-01-01

Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention), these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology-some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1) functional response, expressed by clearance rates; (2) tolerance to starvation, measured by growth and reproduction; and (3) vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not based on differentiation related to biotic niche axes.

Morphological Similarity and Ecological Overlap in Two Rotifer Species

PubMed Central

Gabaldón, Carmen; Montero-Pau, Javier; Serra, Manuel; Carmona, María José

2013-01-01

Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention), these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology—some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1) functional response, expressed by clearance rates; (2) tolerance to starvation, measured by growth and reproduction; and (3) vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not based on differentiation related to biotic niche axes. PMID:23451154

Predicting ecological roles in the rhizosphere using metabolome and transportome modeling

DOE PAGES

Larsen, Peter E.; Collart, Frank R.; Dai, Yang; ...

2015-09-02

The ability to obtain complete genome sequences from bacteria in environmental samples, such as soil samples from the rhizosphere, has highlighted the microbial diversity and complexity of environmental communities. New algorithms to analyze genome sequence information in the context of community structure are needed to enhance our understanding of the specific ecological roles of these organisms in soil environments. We present a machine learning approach using sequenced Pseudomonad genomes coupled with outputs of metabolic and transportomic computational models for identifying the most predictive molecular mechanisms indicative of a Pseudomonad’s ecological role in the rhizosphere: a biofilm, biocontrol agent, promoter ofmore » plant growth, or plant pathogen. Computational predictions of ecological niche were highly accurate overall with models trained on transportomic model output being the most accurate (Leave One Out Validation F-scores between 0.82 and 0.89). The strongest predictive molecular mechanism features for rhizosphere ecological niche overlap with many previously reported analyses of Pseudomonad interactions in the rhizosphere, suggesting that this approach successfully informs a system-scale level understanding of how Pseudomonads sense and interact with their environments. The observation that an organism’s transportome is highly predictive of its ecological niche is a novel discovery and may have implications in our understanding microbial ecology. The framework developed here can be generalized to the analysis of any bacteria across a wide range of environments and ecological niches making this approach a powerful tool for providing insights into functional predictions from bacterial genomic data.« less

Predicting Ecological Roles in the Rhizosphere Using Metabolome and Transportome Modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larsen, Peter E.; Collart, Frank R.; Dai, Yang

2015-09-02

The ability to obtain complete genome sequences from bacteria in environmental samples, such as soil samples from the rhizosphere, has highlighted the microbial diversity and complexity of environmental communities. However, new algorithms to analyze genome sequence information in the context of community structure are needed to enhance our understanding of the specific ecological roles of these organisms in soil environments. We present a machine learning approach using sequenced Pseudomonad genomes coupled with outputs of metabolic and transportomic computational models for identifying the most predictive molecular mechanisms indicative of a Pseudomonad's ecological role in the rhizosphere: a biofilm, biocontrol agent, promotermore » of plant growth, or plant pathogen. Computational predictions of ecological niche were highly accurate overall with models trained on transportomic model output being the most accurate (Leave One Out Validation F-scores between 0.82 and 0.89). The strongest predictive molecular mechanism features for rhizosphere ecological niche overlap with many previously reported analyses of Pseudomonad interactions in the rhizosphere, suggesting that this approach successfully informs a system-scale level understanding of how Pseudomonads sense and interact with their environments. The observation that an organism's transportome is highly predictive of its ecological niche is a novel discovery and may have implications in our understanding microbial ecology. The framework developed here can be generalized to the analysis of any bacteria across a wide range of environments and ecological niches making this approach a powerful tool for providing insights into functional predictions from bacterial genomic data.« less

Introduction to the Special Issue: Beyond traits: integrating behaviour into plant ecology and biology.

PubMed

Cahill, James F

2015-10-26

The way that plants are conceptualized in the context of ecological understanding is changing. In one direction, a reductionist school is pulling plants apart into a list of measured 'traits', from which ecological function and outcomes of species interactions may be inferred. This special issue offers an alternative, and more holistic, view: that the ecological functions performed by a plant will be a consequence not only of their complement of traits but also of the ways in which their component parts are used in response to environmental and social conditions. This is the realm of behavioural ecology, a field that has greatly advanced our understanding of animal biology, ecology and evolution. Included in this special issue are 10 articles focussing not on the tried and true metaphor that plant growth is similar to animal movement, but instead on how application of principles from animal behaviour can improve our ability to understand plant biology and ecology. The goals are not to draw false parallels, nor to anthropomorphize plant biology, but instead to demonstrate how existing and robust theory based on fundamental principles can provide novel understanding for plants. Key to this approach is the recognition that behaviour and intelligence are not the same. Many organisms display complex behaviours despite a lack of cognition (as it is traditionally understood) or any hint of a nervous system. The applicability of behavioural concepts to plants is further enhanced with the realization that all organisms face the same harsh forces of natural selection in the context of finding resources, mates and coping with neighbours. As these ecological realities are often highly variable in space and time, it is not surprising that all organisms-even plants-exhibit complex behaviours to handle this variability. The articles included here address diverse topics in behavioural ecology, as applied to plants: general conceptual understanding, plant nutrient foraging, root-root interactions, and using and helping others. As a group, the articles in this special issue demonstrate how plant ecological understanding can be enhanced through incorporation of behavioural ideas and set the stage for future research in the emerging discipline of plant behavioural ecology. Published by Oxford University Press on behalf of the Annals of Botany Company.

Cancer: a missing link in ecosystem functioning?

PubMed

Vittecoq, Marion; Roche, Benjamin; Daoust, Simon P; Ducasse, Hugo; Missé, Dorothée; Abadie, Jérome; Labrut, Sophie; Renaud, François; Gauthier-Clerc, Michel; Thomas, Frédéric

2013-11-01

Cancer is a disease that affects the majority of metazoan species and, before directly causing host death, is likely to influence the competitive abilities of individuals, their susceptibility to pathogens, their vulnerability to predators, and their ability to disperse. Despite the potential importance of these ecological impacts, cancer is rarely incorporated into model ecosystems. We describe here the diversity of ways in which oncogenic phenomena, from precancerous lesions to generalized metastatic cancers, may affect ecological processes that govern biotic interactions. We argue that oncogenic phenomena, despite their complexity, can have significant and sometimes predictable ecological consequences. Our aim is to provide a new perspective on the ecological and evolutionary significance of cancer in wildlife, and to stimulate research on this topic. Copyright © 2013 Elsevier Ltd. All rights reserved.

Neuroendocrine-Immune Circuits, Phenotypes, and Interactions

PubMed Central

Ashley, Noah T.; Demas, Gregory E.

2016-01-01

Multidirectional interactions among the immune, endocrine, and nervous systems have been demonstrated in humans and non-human animal models for many decades by the biomedical community, but ecological and evolutionary perspectives are lacking. Neuroendocrine-immune interactions can be conceptualized using a series of feedback loops, which culminate into distinct neuroendocrine-immune phenotypes. Behavior can exert profound influences on these phenotypes, which can in turn reciprocally modulate behavior. For example, the behavioral aspects of reproduction, including courtship, aggression, mate selection and parental behaviors can impinge upon neuroendocrine-immune interactions. One classic example is the immunocompetence handicap hypothesis (ICHH), which proposes that steroid hormones act as mediators of traits important for female choice while suppressing the immune system. Reciprocally, neuroendocrine-immune pathways can promote the development of altered behavioral states, such as sickness behavior. Understanding the energetic signals that mediate neuroendocrine-immune crosstalk is an active area of research. Although the field of psychoneuroimmunology (PNI) has begun to explore this crosstalk from a biomedical standpoint, the neuroendocrine-immune-behavior nexus has been relatively underappreciated in comparative species. The field of ecoimmunology, while traditionally emphasizing the study of non-model systems from an ecological evolutionary perspective, often under natural conditions, has focused less on the physiological mechanisms underlying behavioral responses. This review summarizes neuroendocrine-immune interactions using a comparative framework to understand the ecological and evolutionary forces that shape these complex physiological interactions. PMID:27765499

Neuroendocrine-immune circuits, phenotypes, and interactions.

PubMed

Ashley, Noah T; Demas, Gregory E

2017-01-01

Multidirectional interactions among the immune, endocrine, and nervous systems have been demonstrated in humans and non-human animal models for many decades by the biomedical community, but ecological and evolutionary perspectives are lacking. Neuroendocrine-immune interactions can be conceptualized using a series of feedback loops, which culminate into distinct neuroendocrine-immune phenotypes. Behavior can exert profound influences on these phenotypes, which can in turn reciprocally modulate behavior. For example, the behavioral aspects of reproduction, including courtship, aggression, mate selection and parental behaviors can impinge upon neuroendocrine-immune interactions. One classic example is the immunocompetence handicap hypothesis (ICHH), which proposes that steroid hormones act as mediators of traits important for female choice while suppressing the immune system. Reciprocally, neuroendocrine-immune pathways can promote the development of altered behavioral states, such as sickness behavior. Understanding the energetic signals that mediate neuroendocrine-immune crosstalk is an active area of research. Although the field of psychoneuroimmunology (PNI) has begun to explore this crosstalk from a biomedical standpoint, the neuroendocrine-immune-behavior nexus has been relatively underappreciated in comparative species. The field of ecoimmunology, while traditionally emphasizing the study of non-model systems from an ecological evolutionary perspective, often under natural conditions, has focused less on the physiological mechanisms underlying behavioral responses. This review summarizes neuroendocrine-immune interactions using a comparative framework to understand the ecological and evolutionary forces that shape these complex physiological interactions. Copyright © 2016 Elsevier Inc. All rights reserved.

Ecology of the oral microbiome: beyond bacteria

PubMed Central

Baker, Jonathon L.; Bor, Batbileg; Agnello, Melissa; Shi, Wenyuan; He, Xuesong

2017-01-01

Although great strides have been made in understanding the complex bacterial community inhabiting the human oral cavity, for a variety of (mainly technical) reasons the ecological contributions of oral fungi, viruses, phages, and the candidate phyla radiation (CPR) group of ultra-small bacteria have remained understudied. Several recent reports have illustrated the diversity and importance of these organisms in the oral cavity, while TM7x and Candida albicans have served as crucial paradigms for CPR species and oral fungi, respectively. A comprehensive understanding of the oral microbiota and its influence on host health and disease will require a holistic view that emphasizes interactions among different residents within the oral community, as well as their interaction with the host. PMID:28089325

Modeling ecological synergies and trade-offs in livestock production systems in Kenya

NASA Astrophysics Data System (ADS)

Kowal, V. A.; Chaplin-Kramer, R.; Hamel, P.

2016-12-01

Livestock production is critical to maintaining livelihoods in many of the world's rural economies, and interacts with complex ecological processes in ways that present both opportunities and risks for ecosystems and the benefits they provide to people. We present a new dynamic simulation model to examine cattle production in the savannas of East Africa, and its synergies and trade-offs with co-benefits such as wildlife conservation and related tourism. The InVEST rangeland production model couples biomass production from the CENTURY model with diet selection and herbivore physiology from the GRAZPLAN animal biology model. This powerful and flexible model demonstrates that through their interactions mediated by forage availability and tick-borne disease, cattle and wildlife may benefit from integration.

Food Web Designer: a flexible tool to visualize interaction networks.

PubMed

Sint, Daniela; Traugott, Michael

Species are embedded in complex networks of ecological interactions and assessing these networks provides a powerful approach to understand what the consequences of these interactions are for ecosystem functioning and services. This is mandatory to develop and evaluate strategies for the management and control of pests. Graphical representations of networks can help recognize patterns that might be overlooked otherwise. However, there is a lack of software which allows visualizing these complex interaction networks. Food Web Designer is a stand-alone, highly flexible and user friendly software tool to quantitatively visualize trophic and other types of bipartite and tripartite interaction networks. It is offered free of charge for use on Microsoft Windows platforms. Food Web Designer is easy to use without the need to learn a specific syntax due to its graphical user interface. Up to three (trophic) levels can be connected using links cascading from or pointing towards the taxa within each level to illustrate top-down and bottom-up connections. Link width/strength and abundance of taxa can be quantified, allowing generating fully quantitative networks. Network datasets can be imported, saved for later adjustment and the interaction webs can be exported as pictures for graphical display in different file formats. We show how Food Web Designer can be used to draw predator-prey and host-parasitoid food webs, demonstrating that this software is a simple and straightforward tool to graphically display interaction networks for assessing pest control or any other type of interaction in both managed and natural ecosystems from an ecological network perspective.

Pest control of aphids depends on landscape complexity and natural enemy interactions

PubMed Central

Reineking, Björn; Seo, Bumsuk; Steffan-Dewenter, Ingolf

2015-01-01

Aphids are a major concern in agricultural crops worldwide, and control by natural enemies is an essential component of the ecological intensification of agriculture. Although the complexity of agricultural landscapes is known to influence natural enemies of pests, few studies have measured the degree of pest control by different enemy guilds across gradients in landscape complexity. Here, we use multiple natural-enemy exclosures replicated in 18 fields across a gradient in landscape complexity to investigate (1) the strength of natural pest control across landscapes, measured as the difference between pest pressure in the presence and in the absence of natural enemies; (2) the differential contributions of natural enemy guilds to pest control, and the nature of their interactions across landscapes. We show that natural pest control of aphids increased up to six-fold from simple to complex landscapes. In the absence of pest control, aphid population growth was higher in complex than simple landscapes, but was reduced by natural enemies to similar growth rates across all landscapes. The effects of enemy guilds were landscape-dependent. Particularly in complex landscapes, total pest control was supplied by the combined contribution of flying insects and ground-dwellers. Birds had little overall impact on aphid control. Despite evidence for intraguild predation of flying insects by ground-dwellers and birds, the overall effect of enemy guilds on aphid control was complementary. Understanding pest control services at large spatial scales is critical to increase the success of ecological intensification schemes. Our results suggest that, where aphids are the main pest of concern, interactions between natural enemies are largely complementary and lead to a strongly positive effect of landscape complexity on pest control. Increasing the availability of seminatural habitats in agricultural landscapes may thus benefit not only natural enemies, but also the effectiveness of aphid natural pest control. PMID:26734497

Pest control of aphids depends on landscape complexity and natural enemy interactions.

PubMed

Martin, Emily A; Reineking, Björn; Seo, Bumsuk; Steffan-Dewenter, Ingolf

2015-01-01

Aphids are a major concern in agricultural crops worldwide, and control by natural enemies is an essential component of the ecological intensification of agriculture. Although the complexity of agricultural landscapes is known to influence natural enemies of pests, few studies have measured the degree of pest control by different enemy guilds across gradients in landscape complexity. Here, we use multiple natural-enemy exclosures replicated in 18 fields across a gradient in landscape complexity to investigate (1) the strength of natural pest control across landscapes, measured as the difference between pest pressure in the presence and in the absence of natural enemies; (2) the differential contributions of natural enemy guilds to pest control, and the nature of their interactions across landscapes. We show that natural pest control of aphids increased up to six-fold from simple to complex landscapes. In the absence of pest control, aphid population growth was higher in complex than simple landscapes, but was reduced by natural enemies to similar growth rates across all landscapes. The effects of enemy guilds were landscape-dependent. Particularly in complex landscapes, total pest control was supplied by the combined contribution of flying insects and ground-dwellers. Birds had little overall impact on aphid control. Despite evidence for intraguild predation of flying insects by ground-dwellers and birds, the overall effect of enemy guilds on aphid control was complementary. Understanding pest control services at large spatial scales is critical to increase the success of ecological intensification schemes. Our results suggest that, where aphids are the main pest of concern, interactions between natural enemies are largely complementary and lead to a strongly positive effect of landscape complexity on pest control. Increasing the availability of seminatural habitats in agricultural landscapes may thus benefit not only natural enemies, but also the effectiveness of aphid natural pest control.

Deciphering microbial interactions and detecting keystone species with co-occurrence networks

PubMed Central

Berry, David; Widder, Stefanie

2014-01-01

Co-occurrence networks produced from microbial survey sequencing data are frequently used to identify interactions between community members. While this approach has potential to reveal ecological processes, it has been insufficiently validated due to the technical limitations inherent in studying complex microbial ecosystems. Here, we simulate multi-species microbial communities with known interaction patterns using generalized Lotka-Volterra dynamics. We then construct co-occurrence networks and evaluate how well networks reveal the underlying interactions and how experimental and ecological parameters can affect network inference and interpretation. We find that co-occurrence networks can recapitulate interaction networks under certain conditions, but that they lose interpretability when the effects of habitat filtering become significant. We demonstrate that networks suffer from local hot spots of spurious correlation in the neighborhood of hub species that engage in many interactions. We also identify topological features associated with keystone species in co-occurrence networks. This study provides a substantiated framework to guide environmental microbiologists in the construction and interpretation of co-occurrence networks from microbial survey datasets. PMID:24904535

Geography. Focus on Economics.

ERIC Educational Resources Information Center

Watson, George C., Jr.; Domingo, Vernon; Landman, Margaret; Miller, Glenn; Watson, Carlyjane D.; Hopkins, Martha C.

This book allows students to use two specific geographic perspectives - spatial and ecological - to help them understand spatial patterns and processes and the interaction of living and nonliving elements in complex webs of relationships within nature and between nature and society. The set of 12 lessons include: (1) "Where in the World?…

A Scaffolding Framework to Support Learning of Emergent Phenomena Using Multi-Agent-Based Simulation Environments

ERIC Educational Resources Information Center

Basu, Satabdi; Sengupta, Pratim; Biswas, Gautam

2015-01-01

Students from middle school to college have difficulties in interpreting and understanding complex systems such as ecological phenomena. Researchers have suggested that students experience difficulties in reconciling the relationships between individuals, populations, and species, as well as the interactions between organisms and their environment…

Teaching complex ecological concepts through a demonstration garden Biodiversity, invasions and conservation in practice

USDA-ARS?s Scientific Manuscript database

Biodiversity encompasses the variety within and between species in an environment. Native communities host a diverse array of species and interactions between members. Invasions by non-native species reduce biodiversity and a community’s ability to support diverse assemblages, and are one of the lar...

Person-Oriented Approaches to Profiling Learners in Technology-Rich Learning Environments for Ecological Learner Modeling

ERIC Educational Resources Information Center

Jang, Eunice Eunhee; Lajoie, Susanne P.; Wagner, Maryam; Xu, Zhenhua; Poitras, Eric; Naismith, Laura

2017-01-01

Technology-rich learning environments (TREs) provide opportunities for learners to engage in complex interactions involving a multitude of cognitive, metacognitive, and affective states. Understanding learners' distinct learning progressions in TREs demand inquiry approaches that employ well-conceived theoretical accounts of these multiple facets.…

Operationalising a social-ecological system perspective on the Arctic Ocean.

PubMed

Crépin, Anne-Sophie; Gren, Åsa; Engström, Gustav; Ospina, Daniel

2017-12-01

We propose a framework to support management that builds on a social-ecological system perspective on the Arctic Ocean. We illustrate the framework's application for two policy-relevant scenarios of climate-driven change, picturing a shift in zooplankton composition and alternatively a crab invasion. We analyse archetypical system dynamics between the socio-economic, the natural, and the governance systems in these scenarios. Our holistic approach can help managers identify looming problems arising from complex system interactions and prioritise among problems and solutions, even when available data are limited.

Nonlinear Relaxation in Population Dynamics

NASA Astrophysics Data System (ADS)

Cirone, Markus A.; de Pasquale, Ferdinando; Spagnolo, Bernardo

We analyze the nonlinear relaxation of a complex ecosystem composed of many interacting species. The ecological system is described by generalized Lotka-Volterra equations with a multiplicative noise. The transient dynamics is studied in the framework of the mean field theory and with random interaction between the species. We focus on the statistical properties of the asymptotic behaviour of the time integral of the ith population and on the distribution of the population and of the local field.

Distribution of phytoplankton functional types in high-nitrate, low-chlorophyll waters in a new diagnostic ecological indicator model

NASA Astrophysics Data System (ADS)

Palacz, A. P.; St. John, M. A.; Brewin, R. J. W.; Hirata, T.; Gregg, W. W.

2013-11-01

Modeling and monitoring plankton functional types (PFTs) is challenged by the insufficient amount of field measurements of ground truths in both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs and focus on resolving the question of diatom-coccolithophore coexistence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high-latitude areas and indicate seasonal coexistence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, has so far not been captured by state-of-the-art dynamic models, which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources.

Distribution of phytoplankton functional types in high-nitrate low-chlorophyll waters in a new diagnostic ecological indicator model

NASA Astrophysics Data System (ADS)

Palacz, A. P.; St. John, M. A.; Brewin, R. J. W.; Hirata, T.; Gregg, W. W.

2013-05-01

Modeling and monitoring plankton functional types (PFTs) is challenged by insufficient amount of field measurements to ground-truth both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically-sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs, and focus on resolving the question of diatom-coccolithophore co-existence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high latitude areas, and indicate seasonal co-existence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, was so far not captured by state-of-the-art dynamic models which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources.

Matching consumer feeding behaviours and resource traits: a fourth-corner problem in food-web theory.

PubMed

Monteiro, Angelo Barbosa; Faria, Lucas Del Bianco

2018-06-06

For decades, food web theory has proposed phenomenological models for the underlying structure of ecological networks. Generally, these models rely on latent niche variables that match the feeding behaviour of consumers with their resource traits. In this paper, we used a comprehensive database to evaluate different hypotheses on the best dependency structure of trait-matching patterns between consumers and resource traits. We found that consumer feeding behaviours had complex interactions with resource traits; however, few dimensions (i.e. latent variables) could reproduce the trait-matching patterns. We discuss our findings in the light of three food web models designed to reproduce the multidimensionality of food web data; additionally, we discuss how using species traits clarify food webs beyond species pairwise interactions and enable studies to infer ecological generality at larger scales, despite potential taxonomic differences, variations in ecological conditions and differences in species abundance between communities. © 2018 John Wiley & Sons Ltd/CNRS.

Lessons from Philippines MPA Management: Social Ecological Interactions, Participation, and MPA Performance

NASA Astrophysics Data System (ADS)

Twichell, Julia; Pollnac, Richard; Christie, Patrick

2018-06-01

International interest in increasing marine protected area (MPA) coverage reflects broad recognition of the MPA as a key tool for marine ecosystems and fisheries management. Nevertheless, effective management remains a significant challenge. The present study contributes to enriching an understanding of best practices for MPA management through analysis of archived community survey data collected in the Philippines by the Learning Project (LP), a collaboration with United States Coral Triangle Initiative (USCTI), United States Agency for International Development (USAID), and partners. We evaluate stakeholder participation and social ecological interactions among resource users in MPA programs in the Palawan, Occidental Mindoro, and Batangas provinces in the Philippines. Analysis indicates that a complex suite of social ecological factors, including demographics, conservation beliefs, and scientifically correct knowledge influence participation, which in turn is related to perceived MPA performance. Findings indicate positive feedbacks within the system that have potential to strengthen perceptions of MPA success. The results of this evaluation provide empirical reinforcement to current inquiries concerning the role of participation in influencing MPA performance.

The Ecological Role of Volatile and Soluble Secondary Metabolites Produced by Soil Bacteria.

PubMed

Tyc, Olaf; Song, Chunxu; Dickschat, Jeroen S; Vos, Michiel; Garbeva, Paolina

2017-04-01

The rich diversity of secondary metabolites produced by soil bacteria has been appreciated for over a century, and advances in chemical analysis and genome sequencing continue to greatly advance our understanding of this biochemical complexity. However, we are just at the beginning of understanding the physicochemical properties of bacterial metabolites, the factors that govern their production and ecological roles. Interspecific interactions and competitor sensing are among the main biotic factors affecting the production of bacterial secondary metabolites. Many soil bacteria produce both volatile and soluble compounds. In contrast to soluble compounds, volatile organic compounds can diffuse easily through air- and gas-filled pores in the soil and likely play an important role in long-distance microbial interactions. In this review we provide an overview of the most important soluble and volatile classes of secondary metabolites produced by soil bacteria, their ecological roles, and their possible synergistic effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

A stress ecology framework for comprehensive risk assessment of diffuse pollution.

PubMed

van Straalen, Nico M; van Gestel, Cornelis A M

2008-12-01

Environmental pollution is traditionally classified as either localized or diffuse. Local pollution comes from a point source that emits a well-defined cocktail of chemicals, distributed in the environment in the form of a gradient around the source. Diffuse pollution comes from many sources, small and large, that cause an erratic distribution of chemicals, interacting with those from other sources into a complex mixture of low to moderate concentrations over a large area. There is no good method for ecological risk assessment of such types of pollution. We argue that effects of diffuse contamination in the field must be analysed in the wider framework of stress ecology. A multivariate approach can be applied to filter effects of contaminants from the many interacting factors at the ecosystem level. Four case studies are discussed (1) functional and structural properties of terrestrial model ecosystems, (2) physiological profiles of microbial communities, (3) detritivores in reedfield litter, and (4) benthic invertebrates in canal sediment. In each of these cases the data were analysed by multivariate statistics and associations between ecological variables and the levels of contamination were established. We argue that the stress ecology framework is an appropriate assessment instrument for discriminating effects of pollution from other anthropogenic disturbances and naturally varying factors.

The Socio-ecological Fit of Human Responses to Environmental Degradation: An Integrated Assessment Methodology.

PubMed

Briassoulis, Helen

2015-12-01

The scientific and policy interest in the human responses to environmental degradation usually focuses on responses sensu stricto and 'best practices' that potentially abate degradation in affected areas. The transfer of individual, discrete instruments and 'best practices' to different contexts is challenging, however, because socio-ecological systems are complex and environmental degradation is contextual and contingent. To sensibly assess the effectiveness of formal and informal interventions to combat environmental degradation, the paper proposes an integrative, non-reductionist analytic, the 'response assemblage', for the study of 'responses-in-context,' i.e., products of human decisions to utilize environmental resources to satisfy human needs in socio-ecological systems. Response assemblages are defined as geographically and historically unique, provisional, open, territorial wholes, complex compositions emerging from processes of assembling biophysical and human components, including responses sensu stricto, from affected focal and other socio-ecological systems, to serve human goals, one of which may be combatting environmental degradation. The degree of match among the components, called the socio-ecological fit of the response assemblage, indicates how effectively their contextual and contingent interactions maintain the socio-ecological resilience, promote sustainable development, and secure the continuous provision of ecosystem services in a focal socio-ecological system. The paper presents a conceptual approach to the analysis of the socio-ecological fit of response assemblages and details an integrated assessment methodology synthesizing the resilience, assemblage, and 'problem of fit' literature. Lastly, it summarizes the novelty, value, and policy relevance of conceptualizing human responses as response assemblages and of the integrated assessment methodology, reconsiders 'best practices' and suggests selected future research directions.

The Socio-ecological Fit of Human Responses to Environmental Degradation: An Integrated Assessment Methodology

NASA Astrophysics Data System (ADS)

Briassoulis, Helen

2015-12-01

The scientific and policy interest in the human responses to environmental degradation usually focuses on responses sensu stricto and `best practices' that potentially abate degradation in affected areas. The transfer of individual, discrete instruments and `best practices' to different contexts is challenging, however, because socio-ecological systems are complex and environmental degradation is contextual and contingent. To sensibly assess the effectiveness of formal and informal interventions to combat environmental degradation, the paper proposes an integrative, non-reductionist analytic, the `response assemblage', for the study of `responses-in-context,' i.e., products of human decisions to utilize environmental resources to satisfy human needs in socio-ecological systems. Response assemblages are defined as geographically and historically unique, provisional, open, territorial wholes, complex compositions emerging from processes of assembling biophysical and human components, including responses sensu stricto, from affected focal and other socio-ecological systems, to serve human goals, one of which may be combatting environmental degradation. The degree of match among the components, called the socio- ecological fit of the response assemblage, indicates how effectively their contextual and contingent interactions maintain the socio-ecological resilience, promote sustainable development, and secure the continuous provision of ecosystem services in a focal socio-ecological system. The paper presents a conceptual approach to the analysis of the socio-ecological fit of response assemblages and details an integrated assessment methodology synthesizing the resilience, assemblage, and `problem of fit' literature. Lastly, it summarizes the novelty, value, and policy relevance of conceptualizing human responses as response assemblages and of the integrated assessment methodology, reconsiders `best practices' and suggests selected future research directions.

FORUM: Effective management of ecological resilience – are we there yet?

USGS Publications Warehouse

Spears, Bryan M.; Ives, Stephen C.; Angeler, David G.; Allen, Craig R.; Birk, Sebastian; Carvalho, Laurence; Cavers, Stephen; Daunt, Francis; Morton, R. Daniel; Pocock, Michael J. O.; Rhodes, Glenn; Thackeray, Stephen J.

2015-01-01

Ecological resilience is developing into a credible paradigm for policy development and environmental management for preserving natural capital in a rapidly changing world. However, resilience emerges from complex interactions, limiting the translation of theory into practice.Main limitations include the following: (i) difficulty in quantification and detection of changes in ecological resilience, (ii) a lack of empirical evidence to support preventative or proactive management and (iii) difficulties in managing processes operating across socio-ecological systems that vary in space and time.We highlight recent research with the potential to address these limitations including new and/or improved indicators of resilience and tools to assess scale as a driver of resilience.Synthesis and applications. Effective resilience-based management must be adaptive in nature. To support this, we propose an operational model using resilience-based iterative management actions operating across scales.

NetCooperate: a network-based tool for inferring host-microbe and microbe-microbe cooperation.

PubMed

Levy, Roie; Carr, Rogan; Kreimer, Anat; Freilich, Shiri; Borenstein, Elhanan

2015-05-17

Host-microbe and microbe-microbe interactions are often governed by the complex exchange of metabolites. Such interactions play a key role in determining the way pathogenic and commensal species impact their host and in the assembly of complex microbial communities. Recently, several studies have demonstrated how such interactions are reflected in the organization of the metabolic networks of the interacting species, and introduced various graph theory-based methods to predict host-microbe and microbe-microbe interactions directly from network topology. Using these methods, such studies have revealed evolutionary and ecological processes that shape species interactions and community assembly, highlighting the potential of this reverse-ecology research paradigm. NetCooperate is a web-based tool and a software package for determining host-microbe and microbe-microbe cooperative potential. It specifically calculates two previously developed and validated metrics for species interaction: the Biosynthetic Support Score which quantifies the ability of a host species to supply the nutritional requirements of a parasitic or a commensal species, and the Metabolic Complementarity Index which quantifies the complementarity of a pair of microbial organisms' niches. NetCooperate takes as input a pair of metabolic networks, and returns the pairwise metrics as well as a list of potential syntrophic metabolic compounds. The Biosynthetic Support Score and Metabolic Complementarity Index provide insight into host-microbe and microbe-microbe metabolic interactions. NetCooperate determines these interaction indices from metabolic network topology, and can be used for small- or large-scale analyses. NetCooperate is provided as both a web-based tool and an open-source Python module; both are freely available online at http://elbo.gs.washington.edu/software_netcooperate.html.

Using a social-ecological framework to inform the implementation of conservation plans.

PubMed

Guerrero, Angela M; Wilson, Kerrie A

2017-04-01

One of the key determinants of success in biodiversity conservation is how well conservation planning decisions account for the social system in which actions are to be implemented. Understanding elements of how the social and ecological systems interact can help identify opportunities for implementation. Utilizing data from a large-scale conservation initiative in southwestern of Australia, we explored how a social-ecological system framework can be applied to identify how social and ecological factors interact to influence the opportunities for conservation. Using data from semistructured interviews, an online survey, and publicly available data, we developed a conceptual model of the social-ecological system associated with the conservation of the Fitz-Stirling region. We used this model to identify the relevant variables (remnants of vegetation, stakeholder presence, collaboration between stakeholders, and their scale of management) that affect the implementation of conservation actions in the region. We combined measures for these variables to ascertain how areas associated with different levels of ecological importance coincided with areas associated with different levels of stakeholder presence, stakeholder collaboration, and scales of management. We identified areas that could benefit from different implementation strategies, from those suitable for immediate conservation action to areas requiring implementation over the long term to increase on-the-ground capacity and identify mechanisms to incentivize implementation. The application of a social-ecological framework can help conservation planners and practitioners facilitate the integration of ecological and social data to inform the translation of priorities for action into implementation strategies that account for the complexities of conservation problems in a focused way. © 2016 Society for Conservation Biology.

Contact structure, mobility, environmental impact and behaviour: the importance of social forces to infectious disease dynamics and disease ecology

PubMed Central

Gurley, Emily S.

2017-01-01

Human factors, including contact structure, movement, impact on the environment and patterns of behaviour, can have significant influence on the emergence of novel infectious diseases and the transmission and amplification of established ones. As anthropogenic climate change alters natural systems and global economic forces drive land-use and land-cover change, it becomes increasingly important to understand both the ecological and social factors that impact infectious disease outcomes for human populations. While the field of disease ecology explicitly studies the ecological aspects of infectious disease transmission, the effects of the social context on zoonotic pathogen spillover and subsequent human-to-human transmission are comparatively neglected in the literature. The social sciences encompass a variety of disciplines and frameworks for understanding infectious diseases; however, here we focus on four primary areas of social systems that quantitatively and qualitatively contribute to infectious diseases as social–ecological systems. These areas are social mixing and structure, space and mobility, geography and environmental impact, and behaviour and behaviour change. Incorporation of these social factors requires empirical studies for parametrization, phenomena characterization and integrated theoretical modelling of social–ecological interactions. The social–ecological system that dictates infectious disease dynamics is a complex system rich in interacting variables with dynamically significant heterogeneous properties. Future discussions about infectious disease spillover and transmission in human populations need to address the social context that affects particular disease systems by identifying and measuring qualitatively important drivers. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289265

Biomechanics of plant-insect interactions.

PubMed

Whitney, Heather M; Federle, Walter

2013-02-01

Plant-insect interactions are determined by both chemical and physical mechanisms. Biomechanical factors play an important role across many ecological situations, including pollination, herbivory and plant carnivory, and have led to complex adaptations in both plants and insects. However, while mechanical factors involved in some highly specific interactions have been elucidated, more generalised effects may be widespread but are more difficult to isolate, due to the multifunctional properties of the plant surfaces and tissues where interactions occur. Novel methodologies are being developed to investigate the mechanisms of biomechanical interactions and discover to what extent adaptive structures could be exploited via biomimetics. Copyright © 2012 Elsevier Ltd. All rights reserved.

Encyrtid parasitoids of soft scale insects: biology, behavior, and their use in biological control.

PubMed

Kapranas, Apostolos; Tena, Alejandro

2015-01-07

Parasitoids of the hymenopterous family Encyrtidae are one of the most important groups of natural enemies of soft scale insects and have been used extensively in biological control. We summarize existing knowledge of the biology, ecology, and behavior of these parasitoids and how it relates to biological control. Soft scale stage/size and phenology are important determinants of host range and host utilization, which are key aspects in understanding how control by these parasitoids is exerted. Furthermore, the nutritional ecology of encyrtids and their physiological interactions with their hosts affect soft scale insect population dynamics. Lastly, the interactions among encyrtids, heteronomous parasitoids, and ants shape parasitoid species complexes and consequently have a direct impact on the biological control of soft scale insects.

Interactions of social, terrestrial, and marine sub-systems in the Galapagos Islands, Ecuador.

PubMed

Walsh, Stephen J; Mena, Carlos F

2016-12-20

Galapagos is often cited as an example of the conflicts that are emerging between resource conservation and economic development in island ecosystems, as the pressures associated with tourism threaten nature, including the iconic and emblematic species, unique terrestrial landscapes, and special marine environments. In this paper, two projects are described that rely upon dynamic systems models and agent-based models to examine human-environment interactions. We use a theoretical context rooted in complexity theory to guide the development of our models that are linked to social-ecological dynamics. The goal of this paper is to describe key elements, relationships, and processes to inform and enhance our understanding of human-environment interactions in the Galapagos Islands of Ecuador. By formalizing our knowledge of how systems operate and the manner in which key elements are linked in coupled human-natural systems, we specify rules, relationships, and rates of exchange between social and ecological features derived through statistical functions and/or functions specified in theory or practice. The processes described in our models also have practical applications in that they emphasize how political policies generate different human responses and model outcomes, many detrimental to the social-ecological sustainability of the Galapagos Islands.

Interactions of social, terrestrial, and marine sub-systems in the Galapagos Islands, Ecuador

PubMed Central

Walsh, Stephen J.; Mena, Carlos F.

2016-01-01

Galapagos is often cited as an example of the conflicts that are emerging between resource conservation and economic development in island ecosystems, as the pressures associated with tourism threaten nature, including the iconic and emblematic species, unique terrestrial landscapes, and special marine environments. In this paper, two projects are described that rely upon dynamic systems models and agent-based models to examine human–environment interactions. We use a theoretical context rooted in complexity theory to guide the development of our models that are linked to social–ecological dynamics. The goal of this paper is to describe key elements, relationships, and processes to inform and enhance our understanding of human–environment interactions in the Galapagos Islands of Ecuador. By formalizing our knowledge of how systems operate and the manner in which key elements are linked in coupled human–natural systems, we specify rules, relationships, and rates of exchange between social and ecological features derived through statistical functions and/or functions specified in theory or practice. The processes described in our models also have practical applications in that they emphasize how political policies generate different human responses and model outcomes, many detrimental to the social–ecological sustainability of the Galapagos Islands. PMID:27791072

Evolutionary Game Theory Analysis of Tumor Progression

NASA Astrophysics Data System (ADS)

Wu, Amy; Liao, David; Sturm, James; Austin, Robert

2014-03-01

Evolutionary game theory applied to two interacting cell populations can yield quantitative prediction of the future densities of the two cell populations based on the initial interaction terms. We will discuss how in a complex ecology that evolutionary game theory successfully predicts the future densities of strains of stromal and cancer cells (multiple myeloma), and discuss the possible clinical use of such analysis for predicting cancer progression. Supported by the National Science Foundation and the National Cancer Institute.

Local shifts in floral biotic interactions in habitat edges and their effect on quantity and quality of plant offspring

PubMed Central

Fenu, Giuseppe; Bernardo, Liliana

2017-01-01

Abstract Spatial shifts in insect fauna due to ecological heterogeneity can severely constrain plant reproduction. Nonetheless, data showing effects of insect visit patterns and intensity of mutualistic and/or antagonistic plant–insect interactions on plant reproduction over structured ecological gradients remain scarce. We investigated how changes in flower-visitor abundance, identity and behaviour over a forest-open habitat gradient affect plant biotic interactions, and quantitative and qualitative fitness in the edge-specialist Dianthus balbisii. Composition and behaviour of the insects visiting flowers of D. balbisii strongly varied over the study gradient, influencing strength and patterns of plant biotic interactions (i.e. herbivory and pollination likelihood). Seed set comparison in free- and manually pollinated flowers suggested spatial variations in the extent of quantitative pollen limitation, which appeared more pronounced at the gradient extremes. Such variations were congruent to patterns of flower visit and plant biotic interactions. The analyses on seed and seedling viability evidenced that spatial variation in amount and type of pollinators, and frequency of herbivory affected qualitative fitness of D. balbisii by influencing selfing and outcrossing rates. Our work emphasizes the role of plant biotic interactions as a fine-scale mediator of plant fitness in ecotones, highlighting that optimal plant reproduction can take place into a restricted interval of the ecological gradients occurring at forest edges. Reducing the habitat complexity typical of such transition contexts can threat edge-adapted plants. PMID:28775831

A method for estimating vulnerability of Douglas-fir growth to climate change in the Northwestern U.S.

Treesearch

J.S. Littell; D.L. Peterson

2005-01-01

Borrowing from landscape ecology, atmospheric science, and integrated assessment, we aim to understand the complex interactions that determine productivity in montane forests and utilize such relationships to forecast montane forest vulnerability under global climate change. Specifically, we identify relationships for precipitation and temperature that govern the...

Chemical-gene interaction networks and causal reasoning for biological effects prediction and prioritization of contaminants for environmental monitoring and surveillance

EPA Science Inventory

Evaluating the potential human health and ecological risks associated with exposures to complex chemical mixtures in the environment is one of the main challenges of chemical safety assessment and environmental protection. There is a need for approaches that can help to integrat...

Incidental Learning of Melodic Structure of North Indian Music

ERIC Educational Resources Information Center

Rohrmeier, Martin; Widdess, Richard

2017-01-01

Musical knowledge is largely implicit. It is acquired without awareness of its complex rules, through interaction with a large number of samples during musical enculturation. Whereas several studies explored implicit learning of mostly abstract and less ecologically valid features of Western music, very little work has been done with respect to…

Wood and Chemistry – or How to Combine Bob Heath's Two Passions into Entomology Research

USDA-ARS?s Scientific Manuscript database

Plants generally produce complex mixtures of terpenoids that may differ greatly among species. Terpenoids, such C10 monoterpenes and C15 sesquiterpenes, are known to play an important role in the biology and ecology of plants, directly or indirectly influencing their interactions with their biotic e...

Challenges to interdisciplinary discourse

Treesearch

David N. Wear

1999-01-01

Many of the world's critical problems involve hu­man interactions with nature and their long-term implications for environmental quality and the sustainability of resource/ecological systems. These problems are complex defined by the collective behaviors of people as well as by the structure and function of ecosystems suggesting that both the social and the...

Recruitment dynamics in complex life cycles. [of organisms living in marine rocky zone

NASA Technical Reports Server (NTRS)

Roughgarden, Jonathan; Possingham, Hugh; Gaines, Steven

1988-01-01

Factors affecting marine population fluctuations are discussed with particular attention given to a common barnacle species of the Pacific coast of North America. It is shown how models combining larval circulation with adult interactions can potentially forecast population fluctuations. These findings demonstrate how processes in different ecological habitats are coupled.

Modeling dynamic interactions and coherence between marine zooplankton and fishes linked to environmental variability

NASA Astrophysics Data System (ADS)

Liu, Hui; Fogarty, Michael J.; Hare, Jonathan A.; Hsieh, Chih-hao; Glaser, Sarah M.; Ye, Hao; Deyle, Ethan; Sugihara, George

2014-03-01

The dynamics of marine fishes are closely related to lower trophic levels and the environment. Quantitatively understanding ecosystem dynamics linking environmental variability and prey resources to exploited fishes is crucial for ecosystem-based management of marine living resources. However, standard statistical models typically grounded in the concept of linear system may fail to capture the complexity of ecological processes. We have attempted to model ecosystem dynamics using a flexible, nonparametric class of nonlinear forecasting models. We analyzed annual time series of four environmental indices, 22 marine copepod taxa, and four ecologically and commercially important fish species during 1977 to 2009 on Georges Bank, a highly productive and intensively studied area of the northeast U.S. continental shelf ecosystem. We examined the underlying dynamic features of environmental indices and copepods, quantified the dynamic interactions and coherence with fishes, and explored the potential control mechanisms of ecosystem dynamics from a nonlinear perspective. We found: (1) the dynamics of marine copepods and environmental indices exhibiting clear nonlinearity; (2) little evidence of complex dynamics across taxonomic levels of copepods; (3) strong dynamic interactions and coherence between copepods and fishes; and (4) the bottom-up forcing of fishes and top-down control of copepods coexisting as target trophic levels vary. These findings highlight the nonlinear interactions among ecosystem components and the importance of marine zooplankton to fish populations which point to two forcing mechanisms likely interactively regulating the ecosystem dynamics on Georges Bank under a changing environment.

Stable isotope views on ecosystem function: challenging or challenged?

PubMed

Resco, Víctor; Querejeta, José I; Ogle, Kiona; Voltas, Jordi; Sebastià, Maria-Teresa; Serrano-Ortiz, Penélope; Linares, Juan C; Moreno-Gutiérrez, Cristina; Herrero, Asier; Carreira, José A; Torres-Cañabate, Patricia; Valladares, Fernando

2010-06-23

Stable isotopes and their potential for detecting various and complex ecosystem processes are attracting an increasing number of scientists. Progress is challenging, particularly under global change scenarios, but some established views have been challenged. The IX meeting of the Spanish Association of Terrestrial Ecology (AAET, Ubeda, 18-22 October 2009) hosted a symposium on the ecology of stable isotopes where the linear mixing model approach of partitioning sinks and sources of carbon and water fluxes within an ecosystem was challenged, and new applications of stable isotopes for the study of plant interactions were evaluated. Discussion was also centred on the need for networks that monitor ecological processes using stable isotopes and key ideas for fostering future research with isotopes.

Stable isotope views on ecosystem function: challenging or challenged?

PubMed Central

Resco, Víctor; Querejeta, José I.; Ogle, Kiona; Voltas, Jordi; Sebastià, Maria-Teresa; Serrano-Ortiz, Penélope; Linares, Juan C.; Moreno-Gutiérrez, Cristina; Herrero, Asier; Carreira, José A.; Torres-Cañabate, Patricia; Valladares, Fernando

2010-01-01

Stable isotopes and their potential for detecting various and complex ecosystem processes are attracting an increasing number of scientists. Progress is challenging, particularly under global change scenarios, but some established views have been challenged. The IX meeting of the Spanish Association of Terrestrial Ecology (AAET, Úbeda, 18–22 October 2009) hosted a symposium on the ecology of stable isotopes where the linear mixing model approach of partitioning sinks and sources of carbon and water fluxes within an ecosystem was challenged, and new applications of stable isotopes for the study of plant interactions were evaluated. Discussion was also centred on the need for networks that monitor ecological processes using stable isotopes and key ideas for fostering future research with isotopes. PMID:20015858

Time-dependent extinction rate and species abundance in a tangled-nature model of biological evolution.

PubMed

Hall, Matt; Christensen, Kim; di Collobiano, Simone A; Jensen, Henrik Jeldtoft

2002-07-01

We present a model of evolutionary ecology consisting of a web of interacting individuals, a tangle-nature model. The reproduction rate of individuals characterized by their genome depends on the composition of the population in genotype space. Ecological features such as the taxonomy and the macroevolutionary mode of the dynamics are emergent properties. The macrodynamics exhibit intermittent two-mode switching with a gradually decreasing extinction rate. The generated ecologies become gradually better adapted as well as more complex in a collective sense. The form of the species abundance curve compares well with observed functional forms. The model's error threshold can be understood in terms of the characteristics of the two dynamical modes of the system.

Trophic redundancy reduces vulnerability to extinction cascades

PubMed Central

Sanders, Dirk; Thébault, Elisa; Kehoe, Rachel; Frank van Veen, F. J.

2018-01-01

Current species extinction rates are at unprecedentedly high levels. While human activities can be the direct cause of some extinctions, it is becoming increasingly clear that species extinctions themselves can be the cause of further extinctions, since species affect each other through the network of ecological interactions among them. There is concern that the simplification of ecosystems, due to the loss of species and ecological interactions, increases their vulnerability to such secondary extinctions. It is predicted that more complex food webs will be less vulnerable to secondary extinctions due to greater trophic redundancy that can buffer against the effects of species loss. Here, we demonstrate in a field experiment with replicated plant-insect communities, that the probability of secondary extinctions is indeed smaller in food webs that include trophic redundancy. Harvesting one species of parasitoid wasp led to secondary extinctions of other, indirectly linked, species at the same trophic level. This effect was markedly stronger in simple communities than for the same species within a more complex food web. We show that this is due to functional redundancy in the more complex food webs and confirm this mechanism with a food web simulation model by highlighting the importance of the presence and strength of trophic links providing redundancy to those links that were lost. Our results demonstrate that biodiversity loss, leading to a reduction in redundant interactions, can increase the vulnerability of ecosystems to secondary extinctions, which, when they occur, can then lead to further simplification and run-away extinction cascades. PMID:29467292

The role of fire in UK peatland and moorland management: the need for informed, unbiased debate

PubMed Central

Davies, G. Matt; Kettridge, Nicholas; Stoof, Cathelijne R.; Gray, Alan; Ascoli, Davide; Fernandes, Paulo M.; Marrs, Rob; Clay, Gareth D.; McMorrow, Julia; Vandvik, Vigdis

2016-01-01

Fire has been used for centuries to generate and manage some of the UK's cultural landscapes. Despite its complex role in the ecology of UK peatlands and moorlands, there has been a trend of simplifying the narrative around burning to present it as an only ecologically damaging practice. That fire modifies peatland characteristics at a range of scales is clearly understood. Whether these changes are perceived as positive or negative depends upon how trade-offs are made between ecosystem services and the spatial and temporal scales of concern. Here we explore the complex interactions and trade-offs in peatland fire management, evaluating the benefits and costs of managed fire as they are currently understood. We highlight the need for (i) distinguishing between the impacts of fires occurring with differing severity and frequency, and (ii) improved characterization of ecosystem health that incorporates the response and recovery of peatlands to fire. We also explore how recent research has been contextualized within both scientific publications and the wider media and how this can influence non-specialist perceptions. We emphasize the need for an informed, unbiased debate on fire as an ecological management tool that is separated from other aspects of moorland management and from political and economic opinions. This article is part of the themed issue ‘The interaction of fire and mankind’. PMID:27216512

The role of fire in UK peatland and moorland management: the need for informed, unbiased debate.

PubMed

Davies, G Matt; Kettridge, Nicholas; Stoof, Cathelijne R; Gray, Alan; Ascoli, Davide; Fernandes, Paulo M; Marrs, Rob; Allen, Katherine A; Doerr, Stefan H; Clay, Gareth D; McMorrow, Julia; Vandvik, Vigdis

2016-06-05

Fire has been used for centuries to generate and manage some of the UK's cultural landscapes. Despite its complex role in the ecology of UK peatlands and moorlands, there has been a trend of simplifying the narrative around burning to present it as an only ecologically damaging practice. That fire modifies peatland characteristics at a range of scales is clearly understood. Whether these changes are perceived as positive or negative depends upon how trade-offs are made between ecosystem services and the spatial and temporal scales of concern. Here we explore the complex interactions and trade-offs in peatland fire management, evaluating the benefits and costs of managed fire as they are currently understood. We highlight the need for (i) distinguishing between the impacts of fires occurring with differing severity and frequency, and (ii) improved characterization of ecosystem health that incorporates the response and recovery of peatlands to fire. We also explore how recent research has been contextualized within both scientific publications and the wider media and how this can influence non-specialist perceptions. We emphasize the need for an informed, unbiased debate on fire as an ecological management tool that is separated from other aspects of moorland management and from political and economic opinions.This article is part of the themed issue 'The interaction of fire and mankind'. © 2016 The Authors.

Allometric scaling enhances stability in complex food webs.

PubMed

Brose, Ulrich; Williams, Richard J; Martinez, Neo D

2006-11-01

Classic local stability theory predicts that complex ecological networks are unstable and are unlikely to persist despite empiricists' abundant documentation of such complexity in nature. This contradiction has puzzled biologists for decades. While some have explored how stability may be achieved in small modules of a few interacting species, rigorous demonstrations of how large complex and ecologically realistic networks dynamically persist remain scarce and inadequately understood. Here, we help fill this void by combining structural models of complex food webs with nonlinear bioenergetic models of population dynamics parameterized by biological rates that are allometrically scaled to populations' average body masses. Increasing predator-prey body mass ratios increase population persistence up to a saturation level that is reached by invertebrate and ectotherm vertebrate predators when being 10 or 100 times larger than their prey respectively. These values are corroborated by empirical predator-prey body mass ratios from a global data base. Moreover, negative effects of diversity (i.e. species richness) on stability (i.e. population persistence) become neutral or positive relationships at these empirical ratios. These results demonstrate that the predator-prey body mass ratios found in nature may be key to enabling persistence of populations in complex food webs and stabilizing the diversity of natural ecosystems.

Fostering Environmental Literacy For A Changing Earth: Interactive and Participatory Outreach Programs at Biosphere 2

NASA Astrophysics Data System (ADS)

Pavao-Zuckerman, M.; Huxman, T.; Morehouse, B.

2008-12-01

Earth system and ecological sustainability problems are complex outcomes of biological, physical, social, and economic interactions. A common goal of outreach and education programs is to foster a scientifically literate community that possesses the knowledge to contribute to environmental policies and decision making. Uncertainty and variability that is both inherent in Earth system and ecological sciences can confound such goals of improved ecological literacy. Public programs provide an opportunity to engage lay-persons in the scientific method, allowing them to experience science in action and confront these uncertainties face-on. We begin with a definition of scientific literacy that expands its conceptualization of science beyond just a collection of facts and concepts to one that views science as a process to aid understanding of natural phenomena. A process-based scientific literacy allows the public, teachers, and students to assimilate new information, evaluate climate research, and to ultimately make decisions that are informed by science. The Biosphere 2 facility (B2) is uniquely suited for such outreach programs because it allows linking Earth system and ecological science research activities in a large scale controlled environment setting with outreach and education opportunities. A primary outreach goal is to demonstrate science in action to an audience that ranges from K-12 groups to retired citizens. Here we discuss approaches to outreach programs that focus on soil-water-atmosphere-plant interactions and their roles in the impacts and causes of global environmental change. We describe a suite of programs designed to vary the amount of participation a visitor has with the science process (from passive learning to data collection to helping design experiments) to test the hypothesis that active learning fosters increased scientific literacy and the creation of science advocates. We argue that a revised framing of the scientific method with a more open role for citizens in science will have greater success in fostering science literacy and produce a citizenry that is equipped to tackle complex environmental decision making.

Planting increases the abundance and structure complexity of soil core functional genes relevant to carbon and nitrogen cycling

PubMed Central

Wang, Feng; Liang, Yuting; Jiang, Yuji; Yang, Yunfeng; Xue, Kai; Xiong, Jinbo; Zhou, Jizhong; Sun, Bo

2015-01-01

Plants have an important impact on soil microbial communities and their functions. However, how plants determine the microbial composition and network interactions is still poorly understood. During a four-year field experiment, we investigated the functional gene composition of three types of soils (Phaeozem, Cambisols and Acrisol) under maize planting and bare fallow regimes located in cold temperate, warm temperate and subtropical regions, respectively. The core genes were identified using high-throughput functional gene microarray (GeoChip 3.0), and functional molecular ecological networks (fMENs) were subsequently developed with the random matrix theory (RMT)-based conceptual framework. Our results demonstrated that planting significantly (P < 0.05) increased the gene alpha-diversity in terms of richness and Shannon – Simpson’s indexes for all three types of soils and 83.5% of microbial alpha-diversity can be explained by the plant factor. Moreover, planting had significant impacts on the microbial community structure and the network interactions of the microbial communities. The calculated network complexity was higher under maize planting than under bare fallow regimes. The increase of the functional genes led to an increase in both soil respiration and nitrification potential with maize planting, indicating that changes in the soil microbial communities and network interactions influenced ecological functioning. PMID:26396042

Learning About Bird Species on the Primary Level

NASA Astrophysics Data System (ADS)

Randler, Christoph

2009-04-01

Animal species identification is often emphasized as a basic prerequisite for an understanding of ecology because ecological interactions are based on interactions between species at least as it is taught on the school level. Therefore, training identification skills or using identification books seems a worthwhile task in biology education, and should already start on the primary level. On the primary level, however, complex interactions could not be taught but pupils are often interested in basic knowledge about species. We developed a hands-on, group-based and self-determined learning phase organized in workstations. About 138 pupils (2nd-4th graders) participated in this study. The two groups received an identification treatment with six different bird species. These were presented either as soft toys or as taxidermy specimen. Both groups scored similar prior and after the treatment (posttest 1) and with a delay of 6-8 weeks (posttest 2). More complex general linear modeling revealed a significant influence of prior knowledge, treatment and of grade (2nd, 3rd or 4th grade) on the first posttest while in the retention test gender differences emerged. We suggest that soft toys may be of equal value for teaching species identification on the primary level compared to natural taxidermic specimen, especially when considering pricing, insensitivity to handling, and contamination with agents used for preservation.

Simulated tri-trophic networks reveal complex relationships between species diversity and interaction diversity

PubMed Central

Lumpkin, Will; Hurtado, Paul J.; Dyer, Lee A.

2018-01-01

Most of earth’s biodiversity is comprised of interactions among species, yet it is unclear what causes variation in interaction diversity across space and time. We define interaction diversity as the richness and relative abundance of interactions linking species together at scales from localized, measurable webs to entire ecosystems. Large-scale patterns suggest that two basic components of interaction diversity differ substantially and predictably between different ecosystems: overall taxonomic diversity and host specificity of consumers. Understanding how these factors influence interaction diversity, and quantifying the causes and effects of variation in interaction diversity are important goals for community ecology. While previous studies have examined the effects of sampling bias and consumer specialization on determining patterns of ecological networks, these studies were restricted to two trophic levels and did not incorporate realistic variation in species diversity and consumer diet breadth. Here, we developed a food web model to generate tri-trophic ecological networks, and evaluated specific hypotheses about how the diversity of trophic interactions and species diversity are related under different scenarios of species richness, taxonomic abundance, and consumer diet breadth. We investigated the accumulation of species and interactions and found that interactions accumulate more quickly; thus, the accumulation of novel interactions may require less sampling effort than sampling species in order to get reliable estimates of either type of diversity. Mean consumer diet breadth influenced the correlation between species and interaction diversity significantly more than variation in both species richness and taxonomic abundance. However, this effect of diet breadth on interaction diversity is conditional on the number of observed interactions included in the models. The results presented here will help develop realistic predictions of the relationships between consumer diet breadth, interaction diversity, and species diversity within multi-trophic communities, which is critical for the conservation of biodiversity in this period of accelerated global change. PMID:29579077

Simulated tri-trophic networks reveal complex relationships between species diversity and interaction diversity.

PubMed

Pardikes, Nicholas A; Lumpkin, Will; Hurtado, Paul J; Dyer, Lee A

2018-01-01

Most of earth's biodiversity is comprised of interactions among species, yet it is unclear what causes variation in interaction diversity across space and time. We define interaction diversity as the richness and relative abundance of interactions linking species together at scales from localized, measurable webs to entire ecosystems. Large-scale patterns suggest that two basic components of interaction diversity differ substantially and predictably between different ecosystems: overall taxonomic diversity and host specificity of consumers. Understanding how these factors influence interaction diversity, and quantifying the causes and effects of variation in interaction diversity are important goals for community ecology. While previous studies have examined the effects of sampling bias and consumer specialization on determining patterns of ecological networks, these studies were restricted to two trophic levels and did not incorporate realistic variation in species diversity and consumer diet breadth. Here, we developed a food web model to generate tri-trophic ecological networks, and evaluated specific hypotheses about how the diversity of trophic interactions and species diversity are related under different scenarios of species richness, taxonomic abundance, and consumer diet breadth. We investigated the accumulation of species and interactions and found that interactions accumulate more quickly; thus, the accumulation of novel interactions may require less sampling effort than sampling species in order to get reliable estimates of either type of diversity. Mean consumer diet breadth influenced the correlation between species and interaction diversity significantly more than variation in both species richness and taxonomic abundance. However, this effect of diet breadth on interaction diversity is conditional on the number of observed interactions included in the models. The results presented here will help develop realistic predictions of the relationships between consumer diet breadth, interaction diversity, and species diversity within multi-trophic communities, which is critical for the conservation of biodiversity in this period of accelerated global change.

Ecological interactions are evolutionarily conserved across the entire tree of life.

PubMed

Gómez, José M; Verdú, Miguel; Perfectti, Francisco

2010-06-17

Ecological interactions are crucial to understanding both the ecology and the evolution of organisms. Because the phenotypic traits regulating species interactions are largely a legacy of their ancestors, it is widely assumed that ecological interactions are phylogenetically conserved, with closely related species interacting with similar partners. However, the existing empirical evidence is inadequate to appropriately evaluate the hypothesis of phylogenetic conservatism in ecological interactions, because it is both ecologically and taxonomically biased. In fact, most studies on the evolution of ecological interactions have focused on specialized organisms, such as some parasites or insect herbivores, belonging to a limited subset of the overall tree of life. Here we study the evolution of host use in a large and diverse group of interactions comprising both specialist and generalist acellular, unicellular and multicellular organisms. We show that, as previously found for specialized interactions, generalized interactions can be evolutionarily conserved. Significant phylogenetic conservatism of interaction patterns was equally likely to occur in symbiotic and non-symbiotic interactions, as well as in mutualistic and antagonistic interactions. Host-use differentiation among species was higher in phylogenetically conserved clades, irrespective of their generalization degree and taxonomic position within the tree of life. Our findings strongly suggest a shared pattern in the organization of biological systems through evolutionary time, mediated by marked conservatism of ecological interactions among taxa.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konopka, Allan

The activities of complex communities of microbes affect biogeochemical transformations in natural, managed and engineered ecosystems. Meaningfully defining what constitutes a community of interacting microbial populations is not trivial, but is important for rigorous progress in the field. Important elements of research in microbial community ecology include the analysis of functional pathways for nutrient resource and energy flows, mechanistic understanding of interactions between microbial populations and their environment, and the emergent properties of the complex community. Some emergent properties mirror those analyzed by community ecologists who study plants and animals: biological diversity, functional redundancy and system stability. However, because microbesmore » possess mechanisms for the horizontal transfer of genetic information, the metagenome may also be considered a community property.« less

Predictors for reproductive isolation in a ring species complex following genetic and ecological divergence.

PubMed

Pereira, Ricardo J; Monahan, William B; Wake, David B

2011-07-06

Reproductive isolation (RI) is widely accepted as an important "check point" in the diversification process, since it defines irreversible evolutionary trajectories. Much less consensus exists about the processes that might drive RI. Here, we employ a formal quantitative analysis of genetic interactions at several stages of divergence within the ring species complex Ensatina eschscholtzii in order to assess the relative contribution of genetic and ecological divergence for the development of RI. By augmenting previous genetic datasets and adding new ecological data, we quantify levels of genetic and ecological divergence between populations and test how they correlate with a restriction of genetic admixture upon secondary contact. Our results indicate that the isolated effect of ecological divergence between parental populations does not result in reproductively isolated taxa, even when genetic transitions between parental taxa are narrow. Instead, processes associated with overall genetic divergence are the best predictors of reproductive isolation, and when parental taxa diverge in nuclear markers we observe a complete cessation of hybridization, even to sympatric occurrence of distinct evolutionary lineages. Although every parental population has diverged in mitochondrial DNA, its degree of divergence does not predict the extent of RI. These results show that in Ensatina, the evolutionary outcomes of ecological divergence differ from those of genetic divergence. While evident properties of taxa may emerge via ecological divergence, such as adaptation to local environment, RI is likely to be a byproduct of processes that contribute to overall genetic divergence, such as time in geographic isolation, rather than being a direct outcome of local adaptation.

Ecological networks to unravel the routes to horizontal transposon transfers.

PubMed

Venner, Samuel; Miele, Vincent; Terzian, Christophe; Biémont, Christian; Daubin, Vincent; Feschotte, Cédric; Pontier, Dominique

2017-02-01

Transposable elements (TEs) represent the single largest component of numerous eukaryotic genomes, and their activity and dispersal constitute an important force fostering evolutionary innovation. The horizontal transfer of TEs (HTT) between eukaryotic species is a common and widespread phenomenon that has had a profound impact on TE dynamics and, consequently, on the evolutionary trajectory of many species' lineages. However, the mechanisms promoting HTT remain largely unknown. In this article, we argue that network theory combined with functional ecology provides a robust conceptual framework and tools to delineate how complex interactions between diverse organisms may act in synergy to promote HTTs.

Towards a catchment-scale macro-ecological model to support integrated catchment management in Europe

NASA Astrophysics Data System (ADS)

Lerner, R. N.; Lerner, D. N.; Surridge, B.; Paetzold, A.; Harris, B.; Anderson, C. W.

2005-12-01

In Europe, the Water Framework Directive (WFD) is providing a powerful regulatory driver to adopt integrated catchment management, and so pressurizing researchers to build suitable supporting tools. The WFD requires agencies to drive towards `good ecological quality' by 2015. After the initial step of characterising water bodies and the pressures on them, the next substantive step is the preparation of river basin management plans and proposed programmes of measures by 2009. Ecological quality is a complex concept and poorly defined, unless it is taken as a simple measure such as the abundance of a particular species of organism. There is clearly substantial work to do to build a practical but sound definition of ecological quality; practical in the sense of being easy to measure and explain to stakeholders, and sound in the sense that it reflects ecological complexity within catchments, the variability between catchments, and the conflicts demands for goods and services that human society places upon the ecological system. However ecological quality is defined, it will be driven by four interacting groups of factors. These represent the physical, chemical, ecological and socio-economic environments within and encompassing the catchment. Some of these groupings are better understood than others, for example hydrological processes and the transport of solutes are reasonably understood, even though they remain research areas in their own right. There are much larger gaps in our understanding at the interfaces, i.e. predicting how, for example, hydrological processes such as flow and river morphology influence ecological quality. Overall, it is clear we are not yet in a position to build deterministic models of the overall ecological behaviour of catchment. But we need predictive tools to support catchment management agencies in preparing robust plans. This poster describes our current exploration of soft modelling options to build a comprehensive macro-ecological model of UK catchments. This is taking place within the Catchment Science Centre, a joint venture between the University of Sheffield and the Environment Agency.

Nonlinear dynamics in ecosystem response to climatic change: Case studies and policy implications

USGS Publications Warehouse

Burkett, Virginia R.; Wilcox, Douglas A.; Stottlemyer, Robert; Barrow, Wylie; Fagre, Dan; Baron, Jill S.; Price, Jeff; Nielsen, Jennifer L.; Allen, Craig D.; Peterson, David L.; Ruggerone, Greg; Doyle, Thomas

2005-01-01

Many biological, hydrological, and geological processes are interactively linked in ecosystems. These ecological phenomena normally vary within bounded ranges, but rapid, nonlinear changes to markedly different conditions can be triggered by even small differences if threshold values are exceeded. Intrinsic and extrinsic ecological thresholds can lead to effects that cascade among systems, precluding accurate modeling and prediction of system response to climate change. Ten case studies from North America illustrate how changes in climate can lead to rapid, threshold-type responses within ecological communities; the case studies also highlight the role of human activities that alter the rate or direction of system response to climate change. Understanding and anticipating nonlinear dynamics are important aspects of adaptation planning since responses of biological resources to changes in the physical climate system are not necessarily proportional and sometimes, as in the case of complex ecological systems, inherently nonlinear.

Cooperation in microbial communities and their biotechnological applications

PubMed Central

Cavaliere, Matteo; Feng, Song; Soyer, Orkun S.

2017-01-01

Summary Microbial communities are increasingly utilized in biotechnology. Efficiency and productivity in many of these applications depends on the presence of cooperative interactions between members of the community. Two key processes underlying these interactions are the production of public goods and metabolic cross‐feeding, which can be understood in the general framework of ecological and evolutionary (eco‐evo) dynamics. In this review, we illustrate the relevance of cooperative interactions in microbial biotechnological processes, discuss their mechanistic origins and analyse their evolutionary resilience. Cooperative behaviours can be damaged by the emergence of ‘cheating’ cells that benefit from the cooperative interactions but do not contribute to them. Despite this, cooperative interactions can be stabilized by spatial segregation, by the presence of feedbacks between the evolutionary dynamics and the ecology of the community, by the role of regulatory systems coupled to the environmental conditions and by the action of horizontal gene transfer. Cooperative interactions enrich microbial communities with a higher degree of robustness against environmental stress and can facilitate the evolution of more complex traits. Therefore, the evolutionary resilience of microbial communities and their ability to constraint detrimental mutants should be considered to design robust biotechnological applications. PMID:28447371

Evolution in population parameters: density-dependent selection or density-dependent fitness?

PubMed

Travis, Joseph; Leips, Jeff; Rodd, F Helen

2013-05-01

Density-dependent selection is one of earliest topics of joint interest to both ecologists and evolutionary biologists and thus occupies an important position in the histories of these disciplines. This joint interest is driven by the fact that density-dependent selection is the simplest form of feedback between an ecological effect of an organism's own making (crowding due to sustained population growth) and the selective response to the resulting conditions. This makes density-dependent selection perhaps the simplest process through which we see the full reciprocity between ecology and evolution. In this article, we begin by tracing the history of studying the reciprocity between ecology and evolution, which we see as combining the questions of evolutionary ecology with the assumptions and approaches of ecological genetics. In particular, density-dependent fitness and density-dependent selection were critical concepts underlying ideas about adaptation to biotic selection pressures and the coadaptation of interacting species. However, theory points to a critical distinction between density-dependent fitness and density-dependent selection in their influences on complex evolutionary and ecological interactions among coexisting species. Although density-dependent fitness is manifestly evident in empirical studies, evidence of density-dependent selection is much less common. This leads to the larger question of how prevalent and important density-dependent selection might really be. Life-history variation in the least killifish Heterandria formosa appears to reflect the action of density-dependent selection, and yet compelling evidence is elusive, even in this well-studied system, which suggests some important challenges for understanding density-driven feedbacks between ecology and evolution.

Temperate Snake Community in South America: Is Diet Determined by Phylogeny or Ecology?

PubMed Central

Etchepare, Eduardo G.

2015-01-01

Communities are complex and dynamic systems that change with time. The first attempts to explain how they were structured involve contemporary phenomena like ecological interactions between species (e.g., competition and predation) and led to the competition-predation hypothesis. Recently, the deep history hypothesis has emerged, which suggests that profound differences in the evolutionary history of organisms resulted in a number of ecological features that remain largely on species that are part of existing communities. Nevertheless, both phylogenetic structure and ecological interactions can act together to determine the structure of a community. Because diet is one of the main niche axes, in this study we evaluated, for the first time, the impact of ecological and phylogenetic factors on the diet of Neotropical snakes from the subtropical-temperate region of South America. Additionally, we studied their relationship with morphological and environmental aspects to understand the natural history and ecology of this community. A canonical phylogenetical ordination analysis showed that phylogeny explained most of the variation in diet, whereas ecological characters explained very little of this variation. Furthermore, some snakes that shared the habitat showed some degree of diet convergence, in accordance with the competition-predation hypothesis, although phylogeny remained the major determinant in structuring this community. The clade with the greatest variability was the subfamily Dipsadinae, whose members had a very different type of diet, based on soft-bodied invertebrates. Our results are consistent with the deep history hypothesis, and we suggest that the community under study has a deep phylogenetic effect that explains most of the variation in the diet. PMID:25945501

Lineage diversification in a widespread species: roles for niche divergence and conservatism in the common kingsnake, Lampropeltis getula.

PubMed

Alexander Pyron, R; Burbrink, Frank T

2009-08-01

Niche conservatism and niche divergence are both important ecological mechanisms associated with promoting allopatric speciation across geographical barriers. However, the potential for variable responses in widely distributed organisms has not been fully investigated. For allopatric sister lineages, three patterns for the interaction of ecological niche preference and geographical barriers are possible: (i) niche conservatism at a physical barrier; (ii) niche divergence at a physical barrier; and (iii) niche divergence in the absence of a physical barrier. We test for the presence of these patterns in a transcontinentally distributed snake species, the common kingsnake (Lampropeltis getula), to determine the relative frequency of niche conservatism or divergence in a single species complex inhabiting multiple distinct ecoregions. We infer the phylogeographic structure of the kingsnake using a range-wide data set sampled for the mitochondrial gene cytochrome b. We use coalescent simulation methods to test for the presence of structured lineage formation vs. fragmentation of a widespread ancestor. Finally, we use statistical techniques for creating and evaluating ecological niche models to test for conservatism of ecological niche preferences. Significant geographical structure is present in the kingsnake, for which coalescent tests indicate structured population division. Surprisingly, we find evidence for all three patterns of conservatism and divergence. This suggests that ecological niche preferences may be labile on recent phylogenetic timescales, and that lineage formation in widespread species can result from an interaction between inertial tendencies of niche conservatism and natural selection on populations in ecologically divergent habitats.

Population-reaction model and microbial experimental ecosystems for understanding hierarchical dynamics of ecosystems.

PubMed

Hosoda, Kazufumi; Tsuda, Soichiro; Kadowaki, Kohmei; Nakamura, Yutaka; Nakano, Tadashi; Ishii, Kojiro

2016-02-01

Understanding ecosystem dynamics is crucial as contemporary human societies face ecosystem degradation. One of the challenges that needs to be recognized is the complex hierarchical dynamics. Conventional dynamic models in ecology often represent only the population level and have yet to include the dynamics of the sub-organism level, which makes an ecosystem a complex adaptive system that shows characteristic behaviors such as resilience and regime shifts. The neglect of the sub-organism level in the conventional dynamic models would be because integrating multiple hierarchical levels makes the models unnecessarily complex unless supporting experimental data are present. Now that large amounts of molecular and ecological data are increasingly accessible in microbial experimental ecosystems, it is worthwhile to tackle the questions of their complex hierarchical dynamics. Here, we propose an approach that combines microbial experimental ecosystems and a hierarchical dynamic model named population-reaction model. We present a simple microbial experimental ecosystem as an example and show how the system can be analyzed by a population-reaction model. We also show that population-reaction models can be applied to various ecological concepts, such as predator-prey interactions, climate change, evolution, and stability of diversity. Our approach will reveal a path to the general understanding of various ecosystems and organisms. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

To manage inland fisheries is to manage at the social-ecological watershed scale.

PubMed

Nguyen, Vivian M; Lynch, Abigail J; Young, Nathan; Cowx, Ian G; Beard, T Douglas; Taylor, William W; Cooke, Steven J

2016-10-01

Approaches to managing inland fisheries vary between systems and regions but are often based on large-scale marine fisheries principles and thus limited and outdated. Rarely do they adopt holistic approaches that consider the complex interplay among humans, fish, and the environment. We argue that there is an urgent need for a shift in inland fisheries management towards holistic and transdisciplinary approaches that embrace the principles of social-ecological systems at the watershed scale. The interconnectedness of inland fisheries with their associated watershed (biotic, abiotic, and humans) make them extremely complex and challenging to manage and protect. For this reason, the watershed is a logical management unit. To assist management at this scale, we propose a framework that integrates disparate concepts and management paradigms to facilitate inland fisheries management and sustainability. We contend that inland fisheries need to be managed as social-ecological watershed system (SEWS). The framework supports watershed-scale and transboundary governance to manage inland fisheries, and transdisciplinary projects and teams to ensure relevant and applicable monitoring and research. We discuss concepts of social-ecological feedback and interactions of multiple stressors and factors within/between the social-ecological systems. Moreover, we emphasize that management, monitoring, and research on inland fisheries at the watershed scale are needed to ensure long-term sustainable and resilient fisheries. Copyright © 2016. Published by Elsevier Ltd.

Ciguatera fish poisoning in la Habana, Cuba: a study of local social-ecological resilience.

PubMed

Morrison, Karen; Aguiar Prieto, Pablo; Castro Domínguez, Arnaldo; Waltner-Toews, David; Fitzgibbon, John

2008-09-01

Following the collapse of the Cuban economy in the early 1990s, epidemiologists in the Cuban Ministry of Health noticed dramatic increases in reported outbreaks of ciguatera fish poisoning (CFP) in some coastal communities. This article summarizes the results of a comparative case study which applied an ecosystem approach to human health to investigate this issue. Situated learning and complexity theories were used to interpret the results of the investigation. CFP outbreaks are influenced by a complex set of interactions between ecological and socioeconomic processes. This study found that the level of organization of the local sports fishing community and the degree of degradation of the local nearshore marine ecosystem appear to be key factors influencing the diverging levels of CFP outbreaks recorded in the 1990s in the communities studied.

Contact structure, mobility, environmental impact and behaviour: the importance of social forces to infectious disease dynamics and disease ecology.

PubMed

Arthur, Ronan F; Gurley, Emily S; Salje, Henrik; Bloomfield, Laura S P; Jones, James H

2017-05-05

Human factors, including contact structure, movement, impact on the environment and patterns of behaviour, can have significant influence on the emergence of novel infectious diseases and the transmission and amplification of established ones. As anthropogenic climate change alters natural systems and global economic forces drive land-use and land-cover change, it becomes increasingly important to understand both the ecological and social factors that impact infectious disease outcomes for human populations. While the field of disease ecology explicitly studies the ecological aspects of infectious disease transmission, the effects of the social context on zoonotic pathogen spillover and subsequent human-to-human transmission are comparatively neglected in the literature. The social sciences encompass a variety of disciplines and frameworks for understanding infectious diseases; however, here we focus on four primary areas of social systems that quantitatively and qualitatively contribute to infectious diseases as social-ecological systems. These areas are social mixing and structure, space and mobility, geography and environmental impact, and behaviour and behaviour change. Incorporation of these social factors requires empirical studies for parametrization, phenomena characterization and integrated theoretical modelling of social-ecological interactions. The social-ecological system that dictates infectious disease dynamics is a complex system rich in interacting variables with dynamically significant heterogeneous properties. Future discussions about infectious disease spillover and transmission in human populations need to address the social context that affects particular disease systems by identifying and measuring qualitatively important drivers.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'. © 2017 The Author(s).

The Ecological Domain of Warfare

DTIC Science & Technology

2004-06-01

of military performance in terms of e.g., unpredictability, nonlinearity and self organized criticality. [4] The issues of complex interactions...WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Kockums AB,SE-371 82 Karlskrona,Sweden, , 8. PERFORMING ORGANIZATION REPORT...by the architechture for Open Computational Systems itself [Alberts & Hayes (2003)] Author: Jens-Olof Lindh, Security class: UNCLASSIFIED Status

Wildfire Mitigation and Private Lands: Managing Long-Term Vulnerabilities

Treesearch

Brian Muller; Stacey Schulte

2006-01-01

Long-term management of wildfire vulnerability requires strategies that address complex interactions between fire ecology and human settlement. In this paper, we examine the integration of wildfire mitigation and land use planning in county governments in the western U.S. This research relies on data from two sources. First, we conducted a survey of land use...

Introduction: Ecosystem research in a human context [chapter 1

Treesearch

Deborah M. Finch; Joseph A. Tainter

1995-01-01

The Rio Grande/Rio Bravo Basin, which drains a 355,500 square mile area in the southwestern United States and northern Mexico (Fig. I), encompasses numerous land ownership boundaries, vegetation types, desert and woodland ecotones and edges, and urban and rural cultures, forming a complex array of interactive ecological systems. Historically known as the Southwest...

From Attack to Emergence: Interactions between Southern Pine Beetle, Mites, Microbes, and Trees

Treesearch

Kier D. Klepzig; Richard W. Hofstetter

2011-01-01

Bark beetles are among the most ecologically and economically influential organisms in forest ecosystems worldwide. These important organisms are consistently associated in complex symbioses with fungi. Despite this, little is known of the net impacts of the fungi on their vectors, and mites are often completely overlooked. In this chapter, we will describe...

System Thinking and Feeding Relations: Learning with a Live Ecosystem Model

ERIC Educational Resources Information Center

Eilam, Billie

2012-01-01

Considering well-documented difficulties in mastering ecology concepts and system thinking, the aim of the study was to examine 9th graders' understanding of the complex, multilevel, systemic construct of feeding relations, nested within a larger system of a live model. Fifty students interacted with the model and manipulated a variable within it…

The Relationship between School Belonging, Sibling Aggression and Bullying Involvement: Implications for Students with and without Disabilities

ERIC Educational Resources Information Center

Rose, Chad A.; Simpson, Cynthia G.; Ellis, Stephanie K.

2016-01-01

Bullying is grounded in the interactions between an individual and complex social-ecological systems. Therefore, bullying involvement is not just confined to the classroom or school. Recent research suggests that sibling aggression may be a predictor for peer-level aggression. These findings may be more relevant for students with disabilities…

Strand IV Environmental and Community Health, Ecology and Epidemiology of Health, Grades 10, 11, and 12.

ERIC Educational Resources Information Center

New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

A frame of reference concerning health implications, based on the interaction of numerous factors in the physical, social, and biological environments, is provided in this prototype curriculum for grades 10-12. Development of sound techniques in problem solving is encouraged, resulting from the need to understand the nature and complexities of…

Architecture of an Antagonistic Tree/Fungus Network: The Asymmetric Influence of Past Evolutionary History

PubMed Central

Vacher, Corinne; Piou, Dominique; Desprez-Loustau, Marie-Laure

2008-01-01

Background Compartmentalization and nestedness are common patterns in ecological networks. The aim of this study was to elucidate some of the processes shaping these patterns in a well resolved network of host/pathogen interactions. Methology/Principal Findings Based on a long-term (1972–2005) survey of forest health at the regional scale (all French forests; 15 million ha), we uncovered an almost fully connected network of 51 tree taxa and 157 parasitic fungal species. Our analyses revealed that the compartmentalization of the network maps out the ancient evolutionary history of seed plants, but not the ancient evolutionary history of fungal species. The very early divergence of the major fungal phyla may account for this asymmetric influence of past evolutionary history. Unlike compartmentalization, nestedness did not reflect any consistent phylogenetic signal. Instead, it seemed to reflect the ecological features of the current species, such as the relative abundance of tree species and the life-history strategies of fungal pathogens. We discussed how the evolution of host range in fungal species may account for the observed nested patterns. Conclusion/Significance Overall, our analyses emphasized how the current complexity of ecological networks results from the diversification of the species and their interactions over evolutionary times. They confirmed that the current architecture of ecological networks is not only dependant on recent ecological processes. PMID:18320058

Hamiltonian dynamics for complex food webs

NASA Astrophysics Data System (ADS)

Kozlov, Vladimir; Vakulenko, Sergey; Wennergren, Uno

2016-03-01

We investigate stability and dynamics of large ecological networks by introducing classical methods of dynamical system theory from physics, including Hamiltonian and averaging methods. Our analysis exploits the topological structure of the network, namely the existence of strongly connected nodes (hubs) in the networks. We reveal new relations between topology, interaction structure, and network dynamics. We describe mechanisms of catastrophic phenomena leading to sharp changes of dynamics and hence completely altering the ecosystem. We also show how these phenomena depend on the structure of interaction between species. We can conclude that a Hamiltonian structure of biological interactions leads to stability and large biodiversity.

No boundaries: genomes, organisms, and ecological interactions responsible for divergence and reproductive isolation.

PubMed

Etges, William J

2014-01-01

Revealing the genetic basis of traits that cause reproductive isolation, particularly premating or sexual isolation, usually involves the same challenges as most attempts at genotype-phenotype mapping and so requires knowledge of how these traits are expressed in different individuals, populations, and environments, particularly under natural conditions. Genetic dissection of speciation phenotypes thus requires understanding of the internal and external contexts in which underlying genetic elements are expressed. Gene expression is a product of complex interacting factors internal and external to the organism including developmental programs, the genetic background including nuclear-cytotype interactions, epistatic relationships, interactions among individuals or social effects, stochasticity, and prevailing variation in ecological conditions. Understanding of genomic divergence associated with reproductive isolation will be facilitated by functional expression analysis of annotated genomes in organisms with well-studied evolutionary histories, phylogenetic affinities, and known patterns of ecological variation throughout their life cycles. I review progress and prospects for understanding the pervasive role of host plant use on genetic and phenotypic expression of reproductive isolating mechanisms in cactophilic Drosophila mojavensis and suggest how this system can be used as a model for revealing the genetic basis for species formation in organisms where speciation phenotypes are under the joint influences of genetic and environmental factors. © The American Genetic Association. 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A Landscape Indicator Approach to the Identification and Articulation of the Ecological Consequences of Land Cover Change in the Chesapeake Bay Watershed, 1970-2000

USGS Publications Warehouse

Slonecker, Terrence

2008-01-01

The advancement of geographic science in the area of land surface status and trends and land cover change is at the core of the current geographic scientific research of the U.S. Geological Survey (USGS) (McMahon and others, 2005). Perhaps the least developed or articulated aspects of USGS land change science have been the identification and analysis of the ecological consequences of land cover change. Changes in land use and land cover significantly affect the ability of ecosystems to provide essential ecological goods and services, which, in turn, affect the economic, public health, and social benefits that these ecosystems provide. One of the great scientific challenges for geographic science is to understand and calibrate the effects of land use and land cover change and the complex interaction between human and biotic systems at a variety of natural, geographic, and political scales. Understanding the dynamics of land surface change requires an increased understanding of the complex nature of human-environmental systems and will require a suite of scientific tools that include traditional geographic data and analysis methods, such as remote sensing and geographic information systems (GIS), as well as innovative approaches to understanding the dynamics of complex systems. One such approach that has gained much recent scientific attention is the landscape indicator, or landscape assessment, approach, which has been developed with the emergence of the science of landscape ecology.

Forest, Trees, Dynamics: Results from a Novel Wisconsin Card Sorting Test Variant Protocol for Studying Global-Local Attention and Complex Cognitive Processes

PubMed Central

Cowley, Benjamin; Lukander, Kristian

2016-01-01

Background: Recognition of objects and their context relies heavily on the integrated functioning of global and local visual processing. In a realistic setting such as work, this processing becomes a sustained activity, implying a consequent interaction with executive functions. Motivation: There have been many studies of either global-local attention or executive functions; however it is relatively novel to combine these processes to study a more ecological form of attention. We aim to explore the phenomenon of global-local processing during a task requiring sustained attention and working memory. Methods: We develop and test a novel protocol for global-local dissociation, with task structure including phases of divided (“rule search”) and selective (“rule found”) attention, based on the Wisconsin Card Sorting Task (WCST). We test it in a laboratory study with 25 participants, and report on behavior measures (physiological data was also gathered, but not reported here). We develop novel stimuli with more naturalistic levels of information and noise, based primarily on face photographs, with consequently more ecological validity. Results: We report behavioral results indicating that sustained difficulty when participants test their hypotheses impacts matching-task performance, and diminishes the global precedence effect. Results also show a dissociation between subjectively experienced difficulty and objective dimension of performance, and establish the internal validity of the protocol. Contribution: We contribute an advance in the state of the art for testing global-local attention processes in concert with complex cognition. With three results we establish a connection between global-local dissociation and aspects of complex cognition. Our protocol also improves ecological validity and opens options for testing additional interactions in future work. PMID:26941689

Microbial Adhesion and Biofilm Formation on Microfiltration Membranes: A Detailed Characterization Using Model Organisms with Increasing Complexity

PubMed Central

Vanysacker, L.; Denis, C.; Declerck, P.; Piasecka, A.; Vankelecom, I. F. J.

2013-01-01

Since many years, membrane biofouling has been described as the Achilles heel of membrane fouling. In the present study, an ecological assay was performed using model systems with increasing complexity: a monospecies assay using Pseudomonas aeruginosa or Escherichia coli separately, a duospecies assay using both microorganisms, and a multispecies assay using activated sludge with or without spiked P. aeruginosa. The microbial adhesion and biofilm formation were evaluated in terms of bacterial cell densities, species richness, and bacterial community composition on polyvinyldifluoride, polyethylene, and polysulfone membranes. The data show that biofouling formation was strongly influenced by the kind of microorganism, the interactions between the organisms, and the changes in environmental conditions whereas the membrane effect was less important. The findings obtained in this study suggest that more knowledge in species composition and microbial interactions is needed in order to understand the complex biofouling process. This is the first report describing the microbial interactions with a membrane during the biofouling development. PMID:23986906

Using complexity science and negotiation theory to resolve boundary-crossing water issues

NASA Astrophysics Data System (ADS)

Islam, Shafiqul; Susskind, Lawrence

2018-07-01

Many water governance and management issues are complex. The complexity of these issues is related to crossing of multiple boundaries: political, social and jurisdictional, as well as physical, ecological and biogeochemical. Resolution of these issues usually requires interactions of many parties with conflicting values and interests operating across multiple boundaries and scales to make decisions. The interdependence and feedback among interacting variables, processes, actors and institutions are hard to model and difficult to forecast. Thus, decision-making related to complex water problems needs be contingent and adaptive. This paper draws on a number of ideas from complexity science and negotiation theory that may make it easier to cope with the complexities and difficulties of managing boundary crossing water disputes. It begins with the Water Diplomacy Framework that was developed and tested over the past several years. Then, it uses three key ideas from complexity science (interdependence and interconnectedness; uncertainty and feedback; emergence and adaptation) and three from negotiation theory (stakeholder identification and engagement; joint fact finding; and value creation through option generation) to show how application of these ideas can help enhance effectiveness of water management.

Response of Two Mytilids to a Heatwave: The Complex Interplay of Physiology, Behaviour and Ecological Interactions

PubMed Central

Gestoso, Ignacio; Lima, Fernando P.; Vázquez, Elsa; Comeau, Luc A.; Gomes, Filipa; Seabra, Rui

2016-01-01

Different combinations of behavioural and physiological responses may play a crucial role in the ecological success of species, notably in the context of biological invasions. The invasive mussel Xenostrobus securis has successfully colonised the inner part of the Galician Rias Baixas (NW Spain), where it co-occurs with the commercially-important mussel Mytilus galloprovincialis. This study investigated the effect of a heatwave on the physiological and behavioural responses in monospecific or mixed aggregations of these species. In a mesocosm experiment, mussels were exposed to simulated tidal cycles and similar temperature conditions to those experienced in the field during a heat-wave that occurred in the summer of 2013, when field robo-mussels registered temperatures up to 44.5°C at low tide. The overall responses to stress differed markedly between the two species. In monospecific aggregations M. galloprovincialis was more vulnerable than X. securis to heat exposure during emersion. However, in mixed aggregations, the presence of the invader was associated with lower mortality in M. galloprovincialis. The greater sensitivity of M. galloprovincialis to heat exposure was reflected in a higher mortality level, greater induction of Hsp70 protein and higher rates of respiration and gaping activity, which were accompanied by a lower heart rate (bradycardia). The findings show that the invader enhanced the physiological performance of M. galloprovincialis, highlighting the importance of species interactions in regulating responses to environmental stress. Understanding the complex interactions between ecological factors and physiological and behavioural responses of closely-related species is essential for predicting the impacts of invasions in the context of future climate change. PMID:27736896

From single steps to mass migration: the problem of scale in the movement ecology of the Serengeti wildebeest.

PubMed

Torney, Colin J; Hopcraft, J Grant C; Morrison, Thomas A; Couzin, Iain D; Levin, Simon A

2018-05-19

A central question in ecology is how to link processes that occur over different scales. The daily interactions of individual organisms ultimately determine community dynamics, population fluctuations and the functioning of entire ecosystems. Observations of these multiscale ecological processes are constrained by various technological, biological or logistical issues, and there are often vast discrepancies between the scale at which observation is possible and the scale of the question of interest. Animal movement is characterized by processes that act over multiple spatial and temporal scales. Second-by-second decisions accumulate to produce annual movement patterns. Individuals influence, and are influenced by, collective movement decisions, which then govern the spatial distribution of populations and the connectivity of meta-populations. While the field of movement ecology is experiencing unprecedented growth in the availability of movement data, there remain challenges in integrating observations with questions of ecological interest. In this article, we present the major challenges of addressing these issues within the context of the Serengeti wildebeest migration, a keystone ecological phenomena that crosses multiple scales of space, time and biological complexity.This article is part of the theme issue 'Collective movement ecology'. © 2018 The Author(s).

Ecological distribution and population physiology defined by proteomics in a natural microbial community

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muller, R; Denef, Vincent; Kalnejals, Linda

An important challenge in microbial ecology is developing methods that simultaneously examine the physiology of organisms at the molecular level and their ecosystem level interactions in complex natural systems.We integrated extensive proteomic, geochemical, and biological information from 28 microbial communities collected from an acid mine drainage environment and representing a range of biofilm development stages and geochemical conditions to evaluate how the physiologies of the dominant and less abundant organisms change along environmental gradients. The initial colonist dominates across all environments, but its proteome changes between two stable states as communities diversify, implying that interspecies interactions affect this organism smore » metabolism. Its overall physiology is robust to abiotic environmental factors, but strong correlations exist between these factors and certain subsets of proteins, possibly accounting for its wide environmental distribution. Lower abundance populations are patchier in their distribution, and proteomic data indicate that their environmental niches may be constrained by specific sets of abiotic environmental factors. This research establishes an effective strategy to investigate ecological relationships between microbial physiology and the environment for whole communities in situ« less

The History of Ecoimmunology and Its Integration with Disease Ecology

PubMed Central

Brock, Patrick M.; Murdock, Courtney C.; Martin, Lynn B.

2014-01-01

Ecoimmunology is an example of how fruitful integrative approaches to biology can be. Since its emergence, ecoimmunology has sparked constructive debate on a wide range of topics, from the molecular mechanics of immune responses to the role of immunity in shaping the evolution of life histories. To complement the symposium Methods and Mechanisms in Ecoimmunology and commemorate the inception of the Division of Ecoimmunology and Disease Ecology within the Society for Integrative and Comparative Biology, we appraise the origins of ecoimmunology, with a focus on its continuing and valuable integration with disease ecology. Arguably, the greatest contribution of ecoimmunology to wider biology has been the establishment of immunity as an integral part of organismal biology, one that may be regulated to maximize fitness in the context of costs, constraints, and complex interactions. We discuss historical impediments and ongoing progress in ecoimmunology, in particular the thorny issue of what ecoimmunologists should, should not, or cannot measure, and what novel contributions ecoimmunologists have made to the understanding of host–parasite interactions. Finally, we highlight some areas to which ecoimmunology is likely to contribute in the near future. PMID:24838746

Ecological distribution and population physiology defined by proteomics in a natural microbial community

USGS Publications Warehouse

Mueller, Ryan S.; Denef, Vincent J.; Kalnejais, Linda H.; Suttle, K. Blake; Thomas, Brian C.; Wilmes, Paul; Smith, Richard L.; Nordstrom, D. Kirk; McCleskey, R. Blaine; Shah, Menesh B.; VerBekmoes, Nathan C.; Hettich, Robert L.; Banfield, Jillian F.

2010-01-01

An important challenge in microbial ecology is developing methods that simultaneously examine the physiology of organisms at the molecular level and their ecosystem level interactions in complex natural systems. We integrated extensive proteomic, geochemical, and biological information from 28 microbial communities collected from an acid mine drainage environment and representing a range of biofilm development stages and geochemical conditions to evaluate how the physiologies of the dominant and less abundant organisms change along environmental gradients. The initial colonist dominates across all environments, but its proteome changes between two stable states as communities diversify, implying that interspecies interactions affect this organism's metabolism. Its overall physiology is robust to abiotic environmental factors, but strong correlations exist between these factors and certain subsets of proteins, possibly accounting for its wide environmental distribution. Lower abundance populations are patchier in their distribution, and proteomic data indicate that their environmental niches may be constrained by specific sets of abiotic environmental factors. This research establishes an effective strategy to investigate ecological relationships between microbial physiology and the environment for whole communities in situ.

Sustainable Deforestation Evaluation Model and System Dynamics Analysis

PubMed Central

Feng, Huirong; Lim, C. W.; Chen, Liqun; Zhou, Xinnian; Zhou, Chengjun; Lin, Yi

2014-01-01

The current study used the improved fuzzy analytic hierarchy process to construct a sustainable deforestation development evaluation system and evaluation model, which has refined a diversified system to evaluate the theory of sustainable deforestation development. Leveraging the visual image of the system dynamics causal and power flow diagram, we illustrated here that sustainable forestry development is a complex system that encompasses the interaction and dynamic development of ecology, economy, and society and has reflected the time dynamic effect of sustainable forestry development from the three combined effects. We compared experimental programs to prove the direct and indirect impacts of the ecological, economic, and social effects of the corresponding deforest techniques and fully reflected the importance of developing scientific and rational ecological harvesting and transportation technologies. Experimental and theoretical results illustrated that light cableway skidding is an ecoskidding method that is beneficial for the sustainable development of resources, the environment, the economy, and society and forecasted the broad potential applications of light cableway skidding in timber production technology. Furthermore, we discussed the sustainable development countermeasures of forest ecosystems from the aspects of causality, interaction, and harmony. PMID:25254225

Sustainable deforestation evaluation model and system dynamics analysis.

PubMed

Feng, Huirong; Lim, C W; Chen, Liqun; Zhou, Xinnian; Zhou, Chengjun; Lin, Yi

2014-01-01

The current study used the improved fuzzy analytic hierarchy process to construct a sustainable deforestation development evaluation system and evaluation model, which has refined a diversified system to evaluate the theory of sustainable deforestation development. Leveraging the visual image of the system dynamics causal and power flow diagram, we illustrated here that sustainable forestry development is a complex system that encompasses the interaction and dynamic development of ecology, economy, and society and has reflected the time dynamic effect of sustainable forestry development from the three combined effects. We compared experimental programs to prove the direct and indirect impacts of the ecological, economic, and social effects of the corresponding deforest techniques and fully reflected the importance of developing scientific and rational ecological harvesting and transportation technologies. Experimental and theoretical results illustrated that light cableway skidding is an ecoskidding method that is beneficial for the sustainable development of resources, the environment, the economy, and society and forecasted the broad potential applications of light cableway skidding in timber production technology. Furthermore, we discussed the sustainable development countermeasures of forest ecosystems from the aspects of causality, interaction, and harmony.

Comparing species interaction networks along environmental gradients.

PubMed

Pellissier, Loïc; Albouy, Camille; Bascompte, Jordi; Farwig, Nina; Graham, Catherine; Loreau, Michel; Maglianesi, Maria Alejandra; Melián, Carlos J; Pitteloud, Camille; Roslin, Tomas; Rohr, Rudolf; Saavedra, Serguei; Thuiller, Wilfried; Woodward, Guy; Zimmermann, Niklaus E; Gravel, Dominique

2018-05-01

Knowledge of species composition and their interactions, in the form of interaction networks, is required to understand processes shaping their distribution over time and space. As such, comparing ecological networks along environmental gradients represents a promising new research avenue to understand the organization of life. Variation in the position and intensity of links within networks along environmental gradients may be driven by turnover in species composition, by variation in species abundances and by abiotic influences on species interactions. While investigating changes in species composition has a long tradition, so far only a limited number of studies have examined changes in species interactions between networks, often with differing approaches. Here, we review studies investigating variation in network structures along environmental gradients, highlighting how methodological decisions about standardization can influence their conclusions. Due to their complexity, variation among ecological networks is frequently studied using properties that summarize the distribution or topology of interactions such as number of links, connectance, or modularity. These properties can either be compared directly or using a procedure of standardization. While measures of network structure can be directly related to changes along environmental gradients, standardization is frequently used to facilitate interpretation of variation in network properties by controlling for some co-variables, or via null models. Null models allow comparing the deviation of empirical networks from random expectations and are expected to provide a more mechanistic understanding of the factors shaping ecological networks when they are coupled with functional traits. As an illustration, we compare approaches to quantify the role of trait matching in driving the structure of plant-hummingbird mutualistic networks, i.e. a direct comparison, standardized by null models and hypothesis-based metaweb. Overall, our analysis warns against a comparison of studies that rely on distinct forms of standardization, as they are likely to highlight different signals. Fostering a better understanding of the analytical tools available and the signal they detect will help produce deeper insights into how and why ecological networks vary along environmental gradients. © 2017 Cambridge Philosophical Society.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Ye; Zhang, Ping; Qin, Yujia

When trying to discern network interactions among different species/populations in microbial communities interests have been evoked in recent years, but little information is available about temporal dynamics of microbial network interactions in response to environmental perturbations. We modified the random matrix theory-based network approach to discern network succession in groundwater microbial communities in response to emulsified vegetable oil (EVO) amendment for uranium bioremediation. Groundwater microbial communities from one control and seven monitor wells were analysed with a functional gene array (GeoChip 3.0), and functional molecular ecological networks (fMENs) at different time points were reconstructed. Our results showed that the networkmore » interactions were dramatically altered by EVO amendment. Dynamic and resilient succession was evident: fairly simple at the initial stage (Day 0), increasingly complex at the middle period (Days 4, 17, 31), most complex at Day 80, and then decreasingly complex at a later stage (140–269 days). Unlike previous studies in other habitats, negative interactions predominated in a time-series fMEN, suggesting strong competition among different microbial species in the groundwater systems after EVO injection. In particular, several keystone sulfate-reducing bacteria showed strong negative interactions with their network neighbours. These results provide mechanistic understanding of the decreased phylogenetic diversity during environmental perturbations.« less

Late Permian wood-borings reveal an intricate network of ecological relationships.

PubMed

Feng, Zhuo; Wang, Jun; Rößler, Ronny; Ślipiński, Adam; Labandeira, Conrad

2017-09-15

Beetles are the most diverse group of macroscopic organisms since the mid-Mesozoic. Much of beetle speciosity is attributable to myriad life habits, particularly diverse-feeding strategies involving interactions with plant substrates, such as wood. However, the life habits and early evolution of wood-boring beetles remain shrouded in mystery from a limited fossil record. Here we report new material from the upper Permian (Changhsingian Stage, ca. 254-252 million-years ago) of China documenting a microcosm of ecological associations involving a polyphagan wood-borer consuming cambial and wood tissues of the conifer Ningxiaites specialis. This earliest evidence for a component community of several trophically interacting taxa is frozen in time by exceptional preservation. The combination of an entry tunnel through bark, a cambium mother gallery, and up to 11 eggs placed in lateral niches-from which emerge multi-instar larval tunnels that consume cambium, wood and bark-is ecologically convergent with Early Cretaceous bark-beetle borings 120 million-years later.Numerous gaps remain in our knowledge of how groups of organisms interacted in ancient ecosystems. Here, Feng and colleagues describe a late Permian fossil wood-boring beetle microcosm, with the oldest known example of complex tunnel geometry, host tissue response, and the presence of fungi within.

The dual impact of ecology and management on social incentives in marine common-pool resource systems.

PubMed

Klein, E S; Barbier, M R; Watson, J R

2017-08-01

Understanding how and when cooperative human behaviour forms in common-pool resource systems is critical to illuminating social-ecological systems and designing governance institutions that promote sustainable resource use. Before assessing the full complexity of social dynamics, it is essential to understand, concretely and mechanistically, how resource dynamics and human actions interact to create incentives and pay-offs for social behaviours. Here, we investigated how such incentives for information sharing are affected by spatial dynamics and management in a common-pool resource system. Using interviews with fishermen to inform an agent-based model, we reveal generic mechanisms through which, for a given ecological setting characterized by the spatial dynamics of the resource, the two 'human factors' of information sharing and management may heterogeneously impact various members of a group for whom theory would otherwise predict the same strategy. When users can deplete the resource, these interactions are further affected by the management approach. Finally, we discuss the implications of alternative motivations, such as equity among fishermen and consistency of the fleet's output. Our results indicate that resource spatial dynamics, form of management and level of depletion can interact to alter the sociality of people in common-pool resource systems, providing necessary insight for future study of strategic decision processes.

Diversity Increases Indirect Interactions, Attenuates the Intensity of Competition, and Promotes Coexistence.

PubMed

Aschehoug, Erik T; Callaway, Ragan M

2015-10-01

A fundamental assumption of coexistence theory is that competition inevitably decreases species diversity. Consequently, in the quest to understand the ecological regulators of diversity, there has been a great deal of focus on processes with the potential to reduce competitive exclusion. However, the notion that competition must decrease diversity is largely based on the outcome of two-species interaction experiments and models, despite the fact that species rarely interact only in pairs in natural systems. In a field experiment, we found that competition among native perennial plants in multispecies assemblages was far weaker than competition between those same species in pairwise arrangements and that indirect interactions appeared to weaken direct competitive effects. These results suggest that community assembly theory based on pairwise approaches may overestimate the strength of competition and likelihood of competitive exclusion in species-rich communities. We also found that Centaurea stoebe, a North American invader, retained strong competitive effects when competing against North American natives in both pairwise and multispecies assemblages. Our experimental results support an emerging body of theory suggesting that complex networks of competing species may generate strong indirect interactions that can maintain diversity and that ecological differentiation may not be necessary to attenuate competition.

Counteraction of antibiotic production and degradation stabilizes microbial communities

PubMed Central

Kelsic, Eric D.; Zhao, Jeffrey; Vetsigian, Kalin; Kishony, Roy

2015-01-01

Summary A major challenge in theoretical ecology is understanding how natural microbial communities support species diversity1-8, and in particular how antibiotic producing, sensitive and resistant species coexist9-15. While cyclic “rock-paper-scissors” interactions can stabilize communities in spatial environments9-11, coexistence in unstructured environments remains an enigma12,16. Here, using simulations and analytical models, we show that the opposing actions of antibiotic production and degradation enable coexistence even in well-mixed environments. Coexistence depends on 3-way interactions where an antibiotic degrading species attenuates the inhibitory interactions between two other species. These 3-way interactions enable coexistence that is robust to substantial differences in inherent species growth rates and to invasion by “cheating” species that cease producing or degrading antibiotics. At least two antibiotics are required for stability, with greater numbers of antibiotics enabling more complex communities and diverse dynamical behaviors ranging from stable fixed-points to limit cycles and chaos. Together, these results show how multi-species antibiotic interactions can generate ecological stability in both spatial and mixed microbial communities, suggesting strategies for engineering synthetic ecosystems and highlighting the importance of toxin production and degradation for microbial biodiversity. PMID:25992546

Microbiomes: unifying animal and plant systems through the lens of community ecology theory

PubMed Central

Christian, Natalie; Whitaker, Briana K.; Clay, Keith

2015-01-01

The field of microbiome research is arguably one of the fastest growing in biology. Bacteria feature prominently in studies on animal health, but fungi appear to be the more prominent functional symbionts for plants. Despite the similarities in the ecological organization and evolutionary importance of animal-bacterial and plant–fungal microbiomes, there is a general failure across disciplines to integrate the advances made in each system. Researchers studying bacterial symbionts in animals benefit from greater access to efficient sequencing pipelines and taxonomic reference databases, perhaps due to high medical and veterinary interest. However, researchers studying plant–fungal symbionts benefit from the relative tractability of fungi under laboratory conditions and ease of cultivation. Thus each system has strengths to offer, but both suffer from the lack of a common conceptual framework. We argue that community ecology best illuminates complex species interactions across space and time. In this synthesis we compare and contrast the animal-bacterial and plant–fungal microbiomes using six core theories in community ecology (i.e., succession, community assembly, metacommunities, multi-trophic interactions, disturbance, restoration). The examples and questions raised are meant to spark discussion amongst biologists and lead to the integration of these two systems, as well as more informative, manipulatory experiments on microbiomes research. PMID:26441846

Dynamics and ecology of wood in world rivers

NASA Astrophysics Data System (ADS)

Picco, Lorenzo; Bertoldi, Walter; Comiti, Francesco

2017-02-01

Scientific investigation on fluvial wood (FW) has increased greatly during the last decades, mostly for the need to better comprehend and better manage the numerous and complex interactions between the river network and the riparian areas. Following the first two International Conferences on ;Wood in World Rivers;, held at the Oregon State University (USA) in October 2000 and at the University of Stirling (Scotland) in August 2006, the Third Conference was organized in Padova (Italy) in July 2015, by the University of Padova (Dept. Land and Agroforest Environment), University of Trento (Dept. Civil and Environmental Engineering) and Free University of Bolzano (Fac. Science and Technology). This Special Issue contains fifteen papers, thirteen presented during this third conference, which overall cover its main topics: (i) synthesis of the knowledge on physical dynamics and ecological interactions of wood in different geographical regions; (ii) building of a framework for interpreting and applying research results and management approaches; (iii) assessment of physical and biological responses of large wood in stream restoration processes; (iv) exploration of the links between physical and ecological dynamics of large wood, river management, and the communities and cultures in which they are; (v) promotion of a connection between geosciences and ecology which represents a challenge for restoration purposes.

Fractal Hypothesis of the Pelagic Microbial Ecosystem-Can Simple Ecological Principles Lead to Self-Similar Complexity in the Pelagic Microbial Food Web?

PubMed

Våge, Selina; Thingstad, T Frede

2015-01-01

Trophic interactions are highly complex and modern sequencing techniques reveal enormous biodiversity across multiple scales in marine microbial communities. Within the chemically and physically relatively homogeneous pelagic environment, this calls for an explanation beyond spatial and temporal heterogeneity. Based on observations of simple parasite-host and predator-prey interactions occurring at different trophic levels and levels of phylogenetic resolution, we present a theoretical perspective on this enormous biodiversity, discussing in particular self-similar aspects of pelagic microbial food web organization. Fractal methods have been used to describe a variety of natural phenomena, with studies of habitat structures being an application in ecology. In contrast to mathematical fractals where pattern generating rules are readily known, however, identifying mechanisms that lead to natural fractals is not straight-forward. Here we put forward the hypothesis that trophic interactions between pelagic microbes may be organized in a fractal-like manner, with the emergent network resembling the structure of the Sierpinski triangle. We discuss a mechanism that could be underlying the formation of repeated patterns at different trophic levels and discuss how this may help understand characteristic biomass size-spectra that hint at scale-invariant properties of the pelagic environment. If the idea of simple underlying principles leading to a fractal-like organization of the pelagic food web could be formalized, this would extend an ecologists mindset on how biological complexity could be accounted for. It may furthermore benefit ecosystem modeling by facilitating adequate model resolution across multiple scales.

Teleosts as Model Organisms To Understand Host-Microbe Interactions.

PubMed

Lescak, Emily A; Milligan-Myhre, Kathryn C

2017-08-01

Host-microbe interactions are influenced by complex host genetics and environment. Studies across animal taxa have aided our understanding of how intestinal microbiota influence vertebrate development, disease, and physiology. However, traditional mammalian studies can be limited by the use of isogenic strains, husbandry constraints that result in small sample sizes and limited statistical power, reliance on indirect characterization of gut microbial communities from fecal samples, and concerns of whether observations in artificial conditions are actually reflective of what occurs in the wild. Fish models are able to overcome many of these limitations. The extensive variation in the physiology, ecology, and natural history of fish enriches studies of the evolution and ecology of host-microbe interactions. They share physiological and immunological features common among vertebrates, including humans, and harbor complex gut microbiota, which allows identification of the mechanisms driving microbial community assembly. Their accelerated life cycles and large clutch sizes and the ease of sampling both internal and external microbial communities make them particularly well suited for robust statistical studies of microbial diversity. Gnotobiotic techniques, genetic manipulation of the microbiota and host, and transparent juveniles enable novel insights into mechanisms underlying development of the digestive tract and disease states. Many diseases involve a complex combination of genes which are difficult to manipulate in homogeneous model organisms. By taking advantage of the natural genetic variation found in wild fish populations, as well as of the availability of powerful genetic tools, future studies should be able to identify conserved genes and pathways that contribute to human genetic diseases characterized by dysbiosis. Copyright © 2017 Lescak and Milligan-Myhre.

Teleosts as Model Organisms To Understand Host-Microbe Interactions

PubMed Central

2017-01-01

ABSTRACT Host-microbe interactions are influenced by complex host genetics and environment. Studies across animal taxa have aided our understanding of how intestinal microbiota influence vertebrate development, disease, and physiology. However, traditional mammalian studies can be limited by the use of isogenic strains, husbandry constraints that result in small sample sizes and limited statistical power, reliance on indirect characterization of gut microbial communities from fecal samples, and concerns of whether observations in artificial conditions are actually reflective of what occurs in the wild. Fish models are able to overcome many of these limitations. The extensive variation in the physiology, ecology, and natural history of fish enriches studies of the evolution and ecology of host-microbe interactions. They share physiological and immunological features common among vertebrates, including humans, and harbor complex gut microbiota, which allows identification of the mechanisms driving microbial community assembly. Their accelerated life cycles and large clutch sizes and the ease of sampling both internal and external microbial communities make them particularly well suited for robust statistical studies of microbial diversity. Gnotobiotic techniques, genetic manipulation of the microbiota and host, and transparent juveniles enable novel insights into mechanisms underlying development of the digestive tract and disease states. Many diseases involve a complex combination of genes which are difficult to manipulate in homogeneous model organisms. By taking advantage of the natural genetic variation found in wild fish populations, as well as of the availability of powerful genetic tools, future studies should be able to identify conserved genes and pathways that contribute to human genetic diseases characterized by dysbiosis. PMID:28439034

Fractal Hypothesis of the Pelagic Microbial Ecosystem—Can Simple Ecological Principles Lead to Self-Similar Complexity in the Pelagic Microbial Food Web?

PubMed Central

Våge, Selina; Thingstad, T. Frede

2015-01-01

Trophic interactions are highly complex and modern sequencing techniques reveal enormous biodiversity across multiple scales in marine microbial communities. Within the chemically and physically relatively homogeneous pelagic environment, this calls for an explanation beyond spatial and temporal heterogeneity. Based on observations of simple parasite-host and predator-prey interactions occurring at different trophic levels and levels of phylogenetic resolution, we present a theoretical perspective on this enormous biodiversity, discussing in particular self-similar aspects of pelagic microbial food web organization. Fractal methods have been used to describe a variety of natural phenomena, with studies of habitat structures being an application in ecology. In contrast to mathematical fractals where pattern generating rules are readily known, however, identifying mechanisms that lead to natural fractals is not straight-forward. Here we put forward the hypothesis that trophic interactions between pelagic microbes may be organized in a fractal-like manner, with the emergent network resembling the structure of the Sierpinski triangle. We discuss a mechanism that could be underlying the formation of repeated patterns at different trophic levels and discuss how this may help understand characteristic biomass size-spectra that hint at scale-invariant properties of the pelagic environment. If the idea of simple underlying principles leading to a fractal-like organization of the pelagic food web could be formalized, this would extend an ecologists mindset on how biological complexity could be accounted for. It may furthermore benefit ecosystem modeling by facilitating adequate model resolution across multiple scales. PMID:26648929

Assessing spatial coupling in complex population dynamics using mutual prediction and continuity statistics

USGS Publications Warehouse

Nichols, J.M.; Moniz, L.; Nichols, J.D.; Pecora, L.M.; Cooch, E.

2005-01-01

A number of important questions in ecology involve the possibility of interactions or ?coupling? among potential components of ecological systems. The basic question of whether two components are coupled (exhibit dynamical interdependence) is relevant to investigations of movement of animals over space, population regulation, food webs and trophic interactions, and is also useful in the design of monitoring programs. For example, in spatially extended systems, coupling among populations in different locations implies the existence of redundant information in the system and the possibility of exploiting this redundancy in the development of spatial sampling designs. One approach to the identification of coupling involves study of the purported mechanisms linking system components. Another approach is based on time series of two potential components of the same system and, in previous ecological work, has relied on linear cross-correlation analysis. Here we present two different attractor-based approaches, continuity and mutual prediction, for determining the degree to which two population time series (e.g., at different spatial locations) are coupled. Both approaches are demonstrated on a one-dimensional predator?prey model system exhibiting complex dynamics. Of particular interest is the spatial asymmetry introduced into the model as linearly declining resource for the prey over the domain of the spatial coordinate. Results from these approaches are then compared to the more standard cross-correlation analysis. In contrast to cross-correlation, both continuity and mutual prediction are clearly able to discern the asymmetry in the flow of information through this system.

Integrating network ecology with applied conservation: a synthesis and guide to implementation.

PubMed

Kaiser-Bunbury, Christopher N; Blüthgen, Nico

2015-07-10

Ecological networks are a useful tool to study the complexity of biotic interactions at a community level. Advances in the understanding of network patterns encourage the application of a network approach in other disciplines than theoretical ecology, such as biodiversity conservation. So far, however, practical applications have been meagre. Here we present a framework for network analysis to be harnessed to advance conservation management by using plant-pollinator networks and islands as model systems. Conservation practitioners require indicators to monitor and assess management effectiveness and validate overall conservation goals. By distinguishing between two network attributes, the 'diversity' and 'distribution' of interactions, on three hierarchical levels (species, guild/group and network) we identify seven quantitative metrics to describe changes in network patterns that have implications for conservation. Diversity metrics are partner diversity, vulnerability/generality, interaction diversity and interaction evenness, and distribution metrics are the specialization indices d' and [Formula: see text] and modularity. Distribution metrics account for sampling bias and may therefore be suitable indicators to detect human-induced changes to plant-pollinator communities, thus indirectly assessing the structural and functional robustness and integrity of ecosystems. We propose an implementation pathway that outlines the stages that are required to successfully embed a network approach in biodiversity conservation. Most importantly, only if conservation action and study design are aligned by practitioners and ecologists through joint experiments, are the findings of a conservation network approach equally beneficial for advancing adaptive management and ecological network theory. We list potential obstacles to the framework, highlight the shortfall in empirical, mostly experimental, network data and discuss possible solutions. Published by Oxford University Press on behalf of the Annals of Botany Company.

An empirical model of the Baltic Sea reveals the importance of social dynamics for ecological regime shifts.

PubMed

Lade, Steven J; Niiranen, Susa; Hentati-Sundberg, Jonas; Blenckner, Thorsten; Boonstra, Wiebren J; Orach, Kirill; Quaas, Martin F; Österblom, Henrik; Schlüter, Maja

2015-09-01

Regime shifts triggered by human activities and environmental changes have led to significant ecological and socioeconomic consequences in marine and terrestrial ecosystems worldwide. Ecological processes and feedbacks associated with regime shifts have received considerable attention, but human individual and collective behavior is rarely treated as an integrated component of such shifts. Here, we used generalized modeling to develop a coupled social-ecological model that integrated rich social and ecological data to investigate the role of social dynamics in the 1980s Baltic Sea cod boom and collapse. We showed that psychological, economic, and regulatory aspects of fisher decision making, in addition to ecological interactions, contributed both to the temporary persistence of the cod boom and to its subsequent collapse. These features of the social-ecological system also would have limited the effectiveness of stronger fishery regulations. Our results provide quantitative, empirical evidence that incorporating social dynamics into models of natural resources is critical for understanding how resources can be managed sustainably. We also show that generalized modeling, which is well-suited to collaborative model development and does not require detailed specification of causal relationships between system variables, can help tackle the complexities involved in creating and analyzing social-ecological models.

An empirical model of the Baltic Sea reveals the importance of social dynamics for ecological regime shifts

PubMed Central

Lade, Steven J.; Niiranen, Susa; Hentati-Sundberg, Jonas; Blenckner, Thorsten; Boonstra, Wiebren J.; Orach, Kirill; Quaas, Martin F.; Österblom, Henrik; Schlüter, Maja

2015-01-01

Regime shifts triggered by human activities and environmental changes have led to significant ecological and socioeconomic consequences in marine and terrestrial ecosystems worldwide. Ecological processes and feedbacks associated with regime shifts have received considerable attention, but human individual and collective behavior is rarely treated as an integrated component of such shifts. Here, we used generalized modeling to develop a coupled social–ecological model that integrated rich social and ecological data to investigate the role of social dynamics in the 1980s Baltic Sea cod boom and collapse. We showed that psychological, economic, and regulatory aspects of fisher decision making, in addition to ecological interactions, contributed both to the temporary persistence of the cod boom and to its subsequent collapse. These features of the social–ecological system also would have limited the effectiveness of stronger fishery regulations. Our results provide quantitative, empirical evidence that incorporating social dynamics into models of natural resources is critical for understanding how resources can be managed sustainably. We also show that generalized modeling, which is well-suited to collaborative model development and does not require detailed specification of causal relationships between system variables, can help tackle the complexities involved in creating and analyzing social–ecological models. PMID:26283344

Historical Reflections on the Ascendancy of ADHD in North America, c. 1980 - c. 2005

ERIC Educational Resources Information Center

Neufeld, Paul; Foy, Michael

2006-01-01

An ecological niche framework (Hacking, 1998) is utilised to examine the growth of ADHD in North America. The analysis suggests ADHD flourishes, at least in part, due to a complex and historically situated interaction of factors that created a niche within which a particular kind of explanation and treatment for the troubling behaviours of…

The effects of seed dispersal on the simulation of long-term forest landscape change

Treesearch

Hong S. He; David J. Mladenoff

1999-01-01

The study of forest landscape change requires an understanding of the complex interactions of both spatial and temporal factors. Traditionally, forest gap models have been used to simulate change on small and independent plots. While gap models are useful in examining forest ecological dynamics across temporal scales, large, spatial processes, such as seed dispersal,...

Integrating models to investigate critical phenological overlaps in complex ecological interactions: The mountain pine beetle-fungus symbiosis

Treesearch

Audrey Addison; James A. Powell; Barbara J. Bentz; Diana L. Six

2015-01-01

The fates of individual species are often tied to synchronization of phenology, however, few methods have been developed for integrating phenological models involving linked species. In this paper, we focus on mountain pine beetle (MPB, Dendroctonus ponderosae) and its two obligate mutualistic fungi, Grosmannia clavigera and Ophiostoma montium. Growth rates of...

War and peace: social interactions in infections

PubMed Central

Leggett, Helen C.; Brown, Sam P.; Reece, Sarah E.

2014-01-01

One of the most striking facts about parasites and microbial pathogens that has emerged in the fields of social evolution and disease ecology in the past few decades is that these simple organisms have complex social lives, indulging in a variety of cooperative, communicative and coordinated behaviours. These organisms have provided elegant experimental tests of the importance of relatedness, kin discrimination, cooperation and competition, in driving the evolution of social strategies. Here, we briefly review the social behaviours of parasites and microbial pathogens, including their contributions to virulence, and outline how inclusive fitness theory has helped to explain their evolution. We then take a mechanistically inspired ‘bottom-up’ approach, discussing how key aspects of the ways in which parasites and pathogens exploit hosts, namely public goods, mobile elements, phenotypic plasticity, spatial structure and multi-species interactions, contribute to the emergent properties of virulence and transmission. We argue that unravelling the complexities of within-host ecology is interesting in its own right, and also needs to be better incorporated into theoretical evolution studies if social behaviours are to be understood and used to control the spread and severity of infectious diseases. PMID:24686936

Warming Climate and Changing Societies - a Challenge or an Opportunity for Reindeer Herding?

NASA Astrophysics Data System (ADS)

Käyhkö, J.; Horstkotte, T.; Kivinen, S.; Vehmas, J.; Oksanen, L.; Forbes, B. C.; Johansen, B.; Jepsen, J. U.; Markkola, A.; Pulliainen, J.; Olofsson, J.; Oksanen, T.; Utsi, T. A.; Korpimäki, E.; Menard, C.; Ericson, L.

2015-12-01

The Arctic region will warm more rapidly than the global mean, influencing dramatically the northern ecosystems. Simultaneously, our societies transform towards urbanized, highly educated, service-based culture, where a decreasing population will gain its livelihood from primary production. We study various ecosystem interactions in a changing climate and integrate these with reindeer husbandry and the indigenous Sámi culture dependent on it1. Potential climate impacts include the transformation of arctic-alpine tundra to dense scrubland with conceivable consequences to reindeer husbandry, but also global warming due to decreasing albedo. The social-ecological system (SES) of reindeer husbandry includes administrative and ecological processes that do not always correspond (Figure 1). Consequently, management priorities and administration may conflict with local social and ecological processes, bringing about risks of environmental degradation, loss of biodiversity and defeat of traditional livelihoods. We hypothesize the plausibility to support the indigenous reindeer herding livelihood against rapid external changes by utilizing the migratory reindeer grazing system of the Sámi as a management tool for sustaining the high-albedo tundra and mitigating global warming. Our first-of-a-kind satellite-based high resolution vegetation map covering Northern Fennoscandia allows detailed management plans. Our ecological research demonstrates the important role of herbivory on arctic vegetation communities. Interactive workshops with reindeer herders offer indigenous knowledge of state and changes of the ecosystems, and reflect the threats and expectations of the herders. We are currently building models of the complex social-ecological system of Northern Fennoscandia and will report the first findings of the exercise. 1 www.ncoetundra.utu.fi Figure 1. The scales of administrative and ecological processes do not always coincide. This may bring about challenges in managing the social-ecological systems.

Ecological characterization and molecular differentiation of Culex pipiens complex taxa and Culex torrentium in eastern Austria.

PubMed

Zittra, Carina; Flechl, Eva; Kothmayer, Michael; Vitecek, Simon; Rossiter, Heidemarie; Zechmeister, Thomas; Fuehrer, Hans-Peter

2016-04-11

Culex pipiens complex taxa differ in behaviour, ecophysiology and epidemiologic importance. Despite their epidemiologic significance, information on genetic diversity, occurrence and seasonal and spatial distribution patterns of the Cx. pipiens complex is still insufficient. Assessment of seasonal and spatial distribution patterns of Culex pipiens forms and their congener Cx. torrentium is crucial for the understanding of their vector-pathogen dynamics. Female mosquitoes were trapped from April-October 2014 twice a month for a 24-h time period with BG-sentinel traps at 24 sampling sites in eastern Austria, using carbon dioxide as attractant. Ecological forms of Cx. pipiens s.l. and their hybrids were differentiated using the CQ11 locus, and Cx. pipiens forms and their congener Cx. torrentium using the ACE-2 gene. Differential exploitation of ecological niches by Cx. pipiens forms and Cx. torrentium was analysed using likelihood ratio tests. Possible effects of environmental parameters on these taxa were tested using PERMANOVA based on distance matrices and, if significant, were modelled in nMDS ordination space to estimate non-linear relationships. For this study, 1476 Culex spp. were sampled. Culex pipiens f. pipiens representing 87.33 % of the total catch was most abundant, followed by hybrids of both forms (5.62 %), Cx. torrentium (3.79 %) and Cx. pipiens f. molestus (3.25 %). Differences in proportional abundances were found between land cover classes. Ecological parameters affecting seasonal and spatial distribution of these taxa in eastern Austria are precipitation duration, air temperature, sunlight and the interaction term of precipitation amount and the Danube water level, which can be interpreted as a proxy for breeding habitat availability. The Cx. pipiens complex of eastern Austria comprises both ecologically different forms, the mainly ornithophilic form pipiens and the mainly mammalophilic and anthropophilic form molestus. Heterogeneous agricultural areas as areas of coexistence may serve as hybridization zones, resulting in potential bridge vectors between birds and humans. Occurrence, seasonal and spatial distribution patterns of the Cx. pipiens complex and Cx. torrentium and the presence of hybrids between both forms were quantified for the first time in Austria. These findings will improve the knowledge of their vector-pathogen dynamics in this country.

Decoding molecular interactions in microbial communities

PubMed Central

Abreu, Nicole A.; Taga, Michiko E.

2016-01-01

Microbial communities govern numerous fundamental processes on earth. Discovering and tracking molecular interactions among microbes is critical for understanding how single species and complex communities impact their associated host or natural environment. While recent technological developments in DNA sequencing and functional imaging have led to new and deeper levels of understanding, we are limited now by our inability to predict and interpret the intricate relationships and interspecies dependencies within these communities. In this review, we highlight the multifaceted approaches investigators have taken within their areas of research to decode interspecies molecular interactions that occur between microbes. Understanding these principles can give us greater insight into ecological interactions in natural environments and within synthetic consortia. PMID:27417261

A standardized tritrophic small-scale system (TriCosm) for the assessment of stressor-induced effects on aquatic community dynamics.

PubMed

Riedl, Verena; Agatz, Annika; Benstead, Rachel; Ashauer, Roman

2018-04-01

Chemical impacts on the environment are routinely assessed in single-species tests. They are employed to measure direct effects on nontarget organisms, but indirect effects on ecological interactions can only be detected in multispecies tests. Micro- and mesocosms are more complex and environmentally realistic, yet they are less frequently used for environmental risk assessment because resource demand is high, whereas repeatability and statistical power are often low. Test systems fulfilling regulatory needs (i.e., standardization, repeatability, and replication) and the assessment of impacts on species interactions and indirect effects are lacking. In the present study we describe the development of the TriCosm, a repeatable aquatic multispecies test with 3 trophic levels and increased statistical power. High repeatability of community dynamics of 3 interacting aquatic populations (algae, Ceriodaphnia, and Hydra) was found with an average coefficient of variation of 19.5% and the ability to determine small effect sizes. The TriCosm combines benefits of both single-species tests (fulfillment of regulatory requirements) and complex multispecies tests (ecological relevance) and can be used, for instance, at an intermediate tier in environmental risk assessment. Furthermore, comparatively quickly generated population and community toxicity data can be useful for the development and testing of mechanistic effect models. Environ Toxicol Chem 2018;37:1051-1060. © 2017 SETAC. © 2017 SETAC.

Trading biodiversity for pest problems.

PubMed

Lundgren, Jonathan G; Fausti, Scott W

2015-07-01

Recent shifts in agricultural practices have resulted in altered pesticide use patterns, land use intensification, and landscape simplification, all of which threaten biodiversity in and near farms. Pests are major challenges to food security, and responses to pests can represent unintended socioeconomic and environmental costs. Characteristics of the ecological community influence pest populations, but the nature of these interactions remains poorly understood within realistic community complexities and on operating farms. We examine how species diversity and the topology of linkages in species' abundances affect pest abundance on maize farms across the Northern Great Plains. Our results show that increased species diversity, community evenness, and linkage strength and network centrality within a biological network all correlate with significantly reduced pest populations. This supports the assertion that reduced biological complexity on farms is associated with increased pest populations and provides a further justification for diversification of agroecosystems to improve the profitability, safety, and sustainability of food production systems. Bioinventories as comprehensive as the one conducted here are conspicuously absent for most agroecosystems but provide an important baseline for community and ecosystem ecology and the effects of food production on local biodiversity and ecosystem function. Network analyses of abundance correlations of entire communities (rather than focal interactions, for example, trophic interactions) can reveal key network characteristics, especially the importance and nature of network centrality, which aid in understanding how these communities function.

Trading biodiversity for pest problems

PubMed Central

Lundgren, Jonathan G.; Fausti, Scott W.

2015-01-01

Recent shifts in agricultural practices have resulted in altered pesticide use patterns, land use intensification, and landscape simplification, all of which threaten biodiversity in and near farms. Pests are major challenges to food security, and responses to pests can represent unintended socioeconomic and environmental costs. Characteristics of the ecological community influence pest populations, but the nature of these interactions remains poorly understood within realistic community complexities and on operating farms. We examine how species diversity and the topology of linkages in species’ abundances affect pest abundance on maize farms across the Northern Great Plains. Our results show that increased species diversity, community evenness, and linkage strength and network centrality within a biological network all correlate with significantly reduced pest populations. This supports the assertion that reduced biological complexity on farms is associated with increased pest populations and provides a further justification for diversification of agroecosystems to improve the profitability, safety, and sustainability of food production systems. Bioinventories as comprehensive as the one conducted here are conspicuously absent for most agroecosystems but provide an important baseline for community and ecosystem ecology and the effects of food production on local biodiversity and ecosystem function. Network analyses of abundance correlations of entire communities (rather than focal interactions, for example, trophic interactions) can reveal key network characteristics, especially the importance and nature of network centrality, which aid in understanding how these communities function. PMID:26601223

Predator functional response and prey survival: Direct and indirect interactions affecting a marked prey population

USGS Publications Warehouse

Miller, David A.; Grand, J.B.; Fondell, T.F.; Anthony, M.

2006-01-01

1. Predation plays an integral role in many community interactions, with the number of predators and the rate at which they consume prey (i.e. their functional response) determining interaction strengths. Owing to the difficulty of directly observing predation events, attempts to determine the functional response of predators in natural systems are limited. Determining the forms that predator functional responses take in complex systems is important in advancing understanding of community interactions. 2. Prey survival has a direct relationship to the functional response of their predators. We employed this relationship to estimate the functional response for bald eagle Haliaeetus leucocepalus predation of Canada goose Branta canadensis nests. We compared models that incorporated eagle abundance, nest abundance and alternative prey presence to determine the form of the functional response that best predicted intra-annual variation in survival of goose nests. 3. Eagle abundance, nest abundance and the availability of alternative prey were all related to predation rates of goose nests by eagles. There was a sigmoidal relationship between predation rate and prey abundance and prey switching occurred when alternative prey was present. In addition, predation by individual eagles increased as eagle abundance increased. 4. A complex set of interactions among the three species examined in this study determined survival rates of goose nests. Results show that eagle predation had both prey- and predator-dependent components with no support for ratio dependence. In addition, indirect interactions resulting from the availability of alternative prey had an important role in mediating the rate at which eagles depredated nests. As a result, much of the within-season variation in nest survival was due to changing availability of alternative prey consumed by eagles. 5. Empirical relationships drawn from ecological theory can be directly integrated into the estimation process to determine the mechanisms responsible for variation in observed survival rates. The relationship between predator functional response and prey survival offers a flexible and robust method to advance our understanding of predator-prey interactions in many complex natural systems where prey populations are marked and regularly visited. ?? 2006 British Ecological Society.

Wildfire risk as a socioecological pathology

USGS Publications Warehouse

Fischer, A. Paige; Spies, Thomas A; Steelman, Toddi A; Moseley, Cassandra; Johnson, Bart R.; Bailey, John D.; Ager, Alan A; Bourgeron, Patrick S.; Charnley, Susan; Collins, Brandon M.; Kline, Jeffrey D; Leahy, Jessica E; Littell, Jeremy; Millington, James D. A.; Nielsen-Pincus, Max; Olsen, Christine S; Paveglio, Travis B; Roos, Christopher I.; Steen-Adams, Michelle M; Stevens, Forrest R; Vukomanovic, Jelena; White, Eric M; Bowman, David M J S

2016-01-01

Wildfire risk in temperate forests has become a nearly intractable problem that can be characterized as a socioecological “pathology”: that is, a set of complex and problematic interactions among social and ecological systems across multiple spatial and temporal scales. Assessments of wildfire risk could benefit from recognizing and accounting for these interactions in terms of socioecological systems, also known as coupled natural and human systems (CNHS). We characterize the primary social and ecological dimensions of the wildfire risk pathology, paying particular attention to the governance system around wildfire risk, and suggest strategies to mitigate the pathology through innovative planning approaches, analytical tools, and policies. We caution that even with a clear understanding of the problem and possible solutions, the system by which human actors govern fire-prone forests may evolve incrementally in imperfect ways and can be expected to resist change even as we learn better ways to manage CNHS.

Host-parasite oscillation dynamics and evolution in a compartmentalized RNA replication system.

PubMed

Bansho, Yohsuke; Furubayashi, Taro; Ichihashi, Norikazu; Yomo, Tetsuya

2016-04-12

To date, various cellular functions have been reconstituted in vitro such as self-replication systems using DNA, RNA, and proteins. The next important challenges include the reconstitution of the interactive networks of self-replicating species and investigating how such interactions generate complex ecological behaviors observed in nature. Here, we synthesized a simple replication system composed of two self-replicating host and parasitic RNA species. We found that the parasitic RNA eradicates the host RNA under bulk conditions; however, when the system is compartmentalized, a continuous oscillation pattern in the population dynamics of the two RNAs emerges. The oscillation pattern changed as replication proceeded mainly owing to the evolution of the host RNA. These results demonstrate that a cell-like compartment plays an important role in host-parasite ecological dynamics and suggest that the origin of the host-parasite coevolution might date back to the very early stages of the evolution of life.

Discovery of antimicrobial lipodepsipeptides produced by a Serratia sp. within mosquito microbiomes.

PubMed

Ganley, Jack; Carr, Gavin; Ioerger, Thomas; Sacchettini, James; Clardy, Jon; Derbyshire, Emily

2018-04-26

The Anopheles mosquito that harbors the Plasmodium parasite contains a microbiota that can influence both the vector and parasite. In recent years, insect-associated microbes have highlighted the untapped potential of exploiting interspecies interactions to discover bioactive compounds. In this study, we report the discovery of nonribosomal lipodepsipeptides that are produced by a Serratia sp. within the midgut and salivary glands of A. stephensi mosquitoes. The lipodepsipeptides, stephensiolides A-K, have antibiotic activity and facilitate bacterial surface motility. Bioinformatic analyses indicate that the stephensiolides are ubiquitous in nature and are likely important for Serratia spp. colonization within mosquitoes, humans, and other ecological niches. Our results demonstrate the usefulness of probing insect-microbiome interactions, enhance our understanding of the chemical ecology within Anopheles mosquitoes, and provide a secondary metabolite scaffold to further investigate this complex relationship. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Using Social Network Measures in Wildlife Disease Ecology, Epidemiology, and Management

PubMed Central

Silk, Matthew J.; Croft, Darren P.; Delahay, Richard J.; Hodgson, David J.; Boots, Mike; Weber, Nicola; McDonald, Robbie A.

2017-01-01

Abstract Contact networks, behavioral interactions, and shared use of space can all have important implications for the spread of disease in animals. Social networks enable the quantification of complex patterns of interactions; therefore, network analysis is becoming increasingly widespread in the study of infectious disease in animals, including wildlife. We present an introductory guide to using social-network-analytical approaches in wildlife disease ecology, epidemiology, and management. We focus on providing detailed practical guidance for the use of basic descriptive network measures by suggesting the research questions to which each technique is best suited and detailing the software available for each. We also discuss how using network approaches can be used beyond the study of social contacts and across a range of spatial and temporal scales. Finally, we integrate these approaches to examine how network analysis can be used to inform the implementation and monitoring of effective disease management strategies. PMID:28596616

Mapping the ecological networks of microbial communities.

PubMed

Xiao, Yandong; Angulo, Marco Tulio; Friedman, Jonathan; Waldor, Matthew K; Weiss, Scott T; Liu, Yang-Yu

2017-12-11

Mapping the ecological networks of microbial communities is a necessary step toward understanding their assembly rules and predicting their temporal behavior. However, existing methods require assuming a particular population dynamics model, which is not known a priori. Moreover, those methods require fitting longitudinal abundance data, which are often not informative enough for reliable inference. To overcome these limitations, here we develop a new method based on steady-state abundance data. Our method can infer the network topology and inter-taxa interaction types without assuming any particular population dynamics model. Additionally, when the population dynamics is assumed to follow the classic Generalized Lotka-Volterra model, our method can infer the inter-taxa interaction strengths and intrinsic growth rates. We systematically validate our method using simulated data, and then apply it to four experimental data sets. Our method represents a key step towards reliable modeling of complex, real-world microbial communities, such as the human gut microbiota.

Molecular Ecology of Hypersaline Microbial Mats: Current Insights and New Directions.

PubMed

Wong, Hon Lun; Ahmed-Cox, Aria; Burns, Brendan Paul

2016-01-05

Microbial mats are unique geobiological ecosystems that form as a result of complex communities of microorganisms interacting with each other and their physical environment. Both the microorganisms present and the network of metabolic interactions govern ecosystem function therein. These systems are often found in a range of extreme environments, and those found in elevated salinity have been particularly well studied. The purpose of this review is to briefly describe the molecular ecology of select model hypersaline mat systems (Guerrero Negro, Shark Bay, S'Avall, and Kiritimati Atoll), and any potentially modulating effects caused by salinity to community structure. In addition, we discuss several emerging issues in the field (linking function to newly discovered phyla and microbial dark matter), which illustrate the changing paradigm that is seen as technology has rapidly advanced in the study of these extreme and evolutionally significant ecosystems.

Responses to olfactory signals reflect network structure of flower-visitor interactions.

PubMed

Junker, Robert R; Höcherl, Nicole; Blüthgen, Nico

2010-07-01

1. Network analyses provide insights into the diversity and complexity of ecological interactions and have motivated conclusions about community stability and co-evolution. However, biological traits and mechanisms such as chemical signals regulating the interactions between individual species--the microstructure of a network--are poorly understood. 2. We linked the responses of receivers (flower visitors) towards signals (flower scent) to the structure of a highly diverse natural flower-insect network. For each interaction, we define link temperature--a newly developed metric--as the deviation of the observed interaction strength from neutrality, assuming that animals randomly interact with flowers. 3. Link temperature was positively correlated to the specific visitors' responses to floral scents, experimentally examined in a mobile olfactometer. Thus, communication between plants and consumers via phytochemical signals reflects a significant part of the microstructure in a complex network. Negative as well as positive responses towards floral scents contributed to these results, where individual experience was important apart from innate behaviour. 4. Our results indicate that: (1) biological mechanisms have a profound impact on the microstructure of complex networks that underlies the outcome of aggregate statistics, and (2) floral scents act as a filter, promoting the visitation of some flower visitors, but also inhibiting the visitation of others.

A socio-ecological adaptive approach to contaminated mega-site management: from 'control and correct' to 'coping with change'.

PubMed

Schirmer, Mario; Lyon, Ken; Armstrong, James E; Farrell, Katharine N

2012-01-01

Mega-sites have a notable impact on surrounding ecological systems. At such sites there are substantial risks associated with complex socio-ecological interactions that are hard to characterize, let alone model and predict. While the urge to control and clean-up mega-sites (control and correct) is understandable, rather than setting a goal of cleaning up such sites, we suggest a more realistic response strategy is to address these massive and persistent sources of contamination by acknowledging their position as new features of the socio-ecological landscapes within which they are located. As it seems nearly impossible to clean up such sites, we argue for consideration of a 'coping with change' rather than a 'control and correct' approach. This strategy recognizes that the current management option for a mega-site, in light of its physical complexities and due to changing societal preferences, geochemical transformations, hydrogeology knowledge and remedial technology options may not remain optimal in future, and therefore needs to be continuously adapted, as community, ecology, technology and understanding change over time. This approach creates an opportunity to consider the relationship between a mega-site and its human and ecological environments in a different and more dynamic way. Our proposed approach relies on iterative adaptive management to incorporate mega-site management into the overall socio-ecological systems of the site's context. This approach effectively embeds mega-site management planning in a triple bottom line and environmental sustainability structure, rather than simply using single measures of success, such as contaminant-based guidelines. Recognizing that there is probably no best solution for managing a mega-site, we present a starting point for engaging constructively with this seemingly intractable issue. Therefore, we aim to initiate discussion about a new approach to mega-site management, in which the complexity of the problems posed by mega-sites is reflected upon in its entirety. These complexities are associated with uncertainties and unknowns that have to be addressed, as they have an impact on the strategies being developed and applied. We contend that the best that can be hoped for in mega-site management is an acceptable solution for the current state of affairs, with good flexibility to modify strategies as new site conditions, remediation possibilities, community preferences and management objectives develop over time. Copyright © 2011 Elsevier B.V. All rights reserved.

Identity effects dominate the impacts of multiple species extinctions on the functioning of complex food webs.

PubMed

Harvey, Eric; Séguin, Annie; Nozais, Christian; Archambault, Philippe; Gravel, Dominique

2013-01-01

Understanding the impacts of species extinctions on the functioning of food webs is a challenging task because of the complexity of ecological interactions. We report the impacts of experimental species extinctions on the functioning of two food webs of freshwater and marine systems. We used a linear model to partition the variance among the multiple components of the diversity effect (linear group richness, nonlinear group richness, and identity). The identity of each functional group was the best explaining variable of ecosystem functioning for both systems. We assessed the contribution of each functional group in multifunctional space and found that, although the effect of functional group varied across ecosystem functions, some functional groups shared common effects on functions. This study is the first experimental demonstration that functional identity dominates the effects of extinctions on ecosystem functioning, suggesting that generalizations are possible despite the inherent complexity of interactions.

Stability and complexity in model meta-ecosystems

PubMed Central

Gravel, Dominique; Massol, François; Leibold, Mathew A.

2016-01-01

The diversity of life and its organization in networks of interacting species has been a long-standing theoretical puzzle for ecologists. Ever since May's provocative paper challenging whether ‘large complex systems [are] stable' various hypotheses have been proposed to explain when stability should be the rule, not the exception. Spatial dynamics may be stabilizing and thus explain high community diversity, yet existing theory on spatial stabilization is limited, preventing comparisons of the role of dispersal relative to species interactions. Here we incorporate dispersal of organisms and material into stability–complexity theory. We find that stability criteria from classic theory are relaxed in direct proportion to the number of ecologically distinct patches in the meta-ecosystem. Further, we find the stabilizing effect of dispersal is maximal at intermediate intensity. Our results highlight how biodiversity can be vulnerable to factors, such as landscape fragmentation and habitat loss, that isolate local communities. PMID:27555100

Functional responses and scaling in predator-prey interactions of marine fishes: contemporary issues and emerging concepts.

PubMed

Hunsicker, Mary E; Ciannelli, Lorenzo; Bailey, Kevin M; Buckel, Jeffrey A; Wilson White, J; Link, Jason S; Essington, Timothy E; Gaichas, Sarah; Anderson, Todd W; Brodeur, Richard D; Chan, Kung-Sik; Chen, Kun; Englund, Göran; Frank, Kenneth T; Freitas, Vânia; Hixon, Mark A; Hurst, Thomas; Johnson, Darren W; Kitchell, James F; Reese, Doug; Rose, George A; Sjodin, Henrik; Sydeman, William J; van der Veer, Henk W; Vollset, Knut; Zador, Stephani

2011-12-01

Predator-prey interactions are a primary structuring force vital to the resilience of marine communities and sustainability of the world's oceans. Human influences on marine ecosystems mediate changes in species interactions. This generality is evinced by the cascading effects of overharvesting top predators on the structure and function of marine ecosystems. It follows that ecological forecasting, ecosystem management, and marine spatial planning require a better understanding of food web relationships. Characterising and scaling predator-prey interactions for use in tactical and strategic tools (i.e. multi-species management and ecosystem models) are paramount in this effort. Here, we explore what issues are involved and must be considered to advance the use of predator-prey theory in the context of marine fisheries science. We address pertinent contemporary ecological issues including (1) the approaches and complexities of evaluating predator responses in marine systems; (2) the 'scaling up' of predator-prey interactions to the population, community, and ecosystem level; (3) the role of predator-prey theory in contemporary fisheries and ecosystem modelling approaches; and (4) directions for the future. Our intent is to point out needed research directions that will improve our understanding of predator-prey interactions in the context of the sustainable marine fisheries and ecosystem management. 2011 Blackwell Publishing Ltd/CNRS.

Diversity, structure and convergent evolution of the global sponge microbiome

PubMed Central

Thomas, Torsten; Moitinho-Silva, Lucas; Lurgi, Miguel; Björk, Johannes R.; Easson, Cole; Astudillo-García, Carmen; Olson, Julie B.; Erwin, Patrick M.; López-Legentil, Susanna; Luter, Heidi; Chaves-Fonnegra, Andia; Costa, Rodrigo; Schupp, Peter J.; Steindler, Laura; Erpenbeck, Dirk; Gilbert, Jack; Knight, Rob; Ackermann, Gail; Victor Lopez, Jose; Taylor, Michael W.; Thacker, Robert W.; Montoya, Jose M.; Hentschel, Ute; Webster, Nicole S.

2016-01-01

Sponges (phylum Porifera) are early-diverging metazoa renowned for establishing complex microbial symbioses. Here we present a global Porifera microbiome survey, set out to establish the ecological and evolutionary drivers of these host–microbe interactions. We show that sponges are a reservoir of exceptional microbial diversity and major contributors to the total microbial diversity of the world's oceans. Little commonality in species composition or structure is evident across the phylum, although symbiont communities are characterized by specialists and generalists rather than opportunists. Core sponge microbiomes are stable and characterized by generalist symbionts exhibiting amensal and/or commensal interactions. Symbionts that are phylogenetically unique to sponges do not disproportionally contribute to the core microbiome, and host phylogeny impacts complexity rather than composition of the symbiont community. Our findings support a model of independent assembly and evolution in symbiont communities across the entire host phylum, with convergent forces resulting in analogous community organization and interactions. PMID:27306690

Differences in foraging ecology align with genetically divergent ecotypes of a highly mobile marine top predator.

PubMed

Jeglinski, Jana W E; Wolf, Jochen B W; Werner, Christiane; Costa, Daniel P; Trillmich, Fritz

2015-12-01

Foraging differentiation within a species can contribute to restricted gene flow between ecologically different groups, promoting ecological speciation. Galapagos sea lions (Zalophus wollebaeki) show genetic and morphological divergence between the western and central archipelago, possibly as a result of an ecologically mediated contrast in the marine habitat. We use global positioning system (GPS) data, time-depth recordings (TDR), stable isotope and scat data to compare foraging habitat characteristics, diving behaviour and diet composition of Galapagos sea lions from a western and a central colony. We consider both juvenile and adult life stages to assess the potential role of ontogenetic shifts that can be crucial in shaping foraging behaviour and habitat choice for life. We found differences in foraging habitat use, foraging style and diet composition that aligned with genetic differentiation. These differences were consistent between juvenile and adult sea lions from the same colony, overriding age-specific behavioural differences. Our study contributes to an understanding of the complex interaction of ecological condition, plastic behavioural response and genetic make-up of interconnected populations.

Fort Collins Science Center: Ecosystem Dynamics

USGS Publications Warehouse

Bowen, Zack

2004-01-01

Current studies fall into five general areas. Herbivore-Ecosystem Interactions examines the efficacy of multiple controls on selected herbivore populations and cascading effects through predator-herbivore-plant-soil linkages. Riparian Ecology is concerned with interactions among streamflow, fluvial geomorphology, and riparian vegetation. Integrated Fire Science focuses on the effects of fire on plant and animal communities at multiple scales, and on the interactions between post-fire plant, runoff, and erosion processes. Reference Ecosystems comprises long-term, place-based studies of ecosystem biogeochemistry. Finally, Integrated Assessments is investigating how to synthesize multiple ecosystem stressors and responses over complex landscapes in ways that are useful for management and planning.

The evolutionary ecology of the Lygaeidae

PubMed Central

Burdfield-Steel, Emily R; Shuker, David M

2014-01-01

The Lygaeidae (sensu lato) are a highly successful family of true bugs found worldwide, yet many aspects of their ecology and evolution remain obscure or unknown. While a few species have attracted considerable attention as model species for the study of insect physiology, it is only relatively recently that biologists have begun to explore aspects of their behavior, life history evolution, and patterns of intra- and interspecific ecological interactions across more species. As a result though, a range of new phenotypes and opportunities for addressing current questions in evolutionary ecology has been uncovered. For example, researchers have revealed hitherto unexpectedly rich patterns of bacterial symbiosis, begun to explore the evolutionary function of the family's complex genitalia, and also found evidence of parthenogenesis. Here we review our current understanding of the biology and ecology of the group as a whole, focusing on several of the best-studied characteristics of the group, including aposematism (i.e., the evolution of warning coloration), chemical communication, sexual selection (especially, postcopulatory sexual selection), sexual conflict, and patterns of host-endosymbiont coevolution. Importantly, many of these aspects of lygaeid biology are likely to interact, offering new avenues for research, for instance into how the evolution of aposematism influences sexual selection. With the growing availability of genomic tools for previously “non-model” organisms, combined with the relative ease of keeping many of the polyphagous species in the laboratory, we argue that these bugs offer many opportunities for behavioral and evolutionary ecologists. PMID:25360267

Higher order scaffoldin assembly in Ruminococcus flavefaciens cellulosome is coordinated by a discrete cohesin-dockerin interaction.

PubMed

Bule, Pedro; Pires, Virgínia M R; Alves, Victor D; Carvalho, Ana Luísa; Prates, José A M; Ferreira, Luís M A; Smith, Steven P; Gilbert, Harry J; Noach, Ilit; Bayer, Edward A; Najmudin, Shabir; Fontes, Carlos M G A

2018-05-03

Cellulosomes are highly sophisticated molecular nanomachines that participate in the deconstruction of complex polysaccharides, notably cellulose and hemicellulose. Cellulosomal assembly is orchestrated by the interaction of enzyme-borne dockerin (Doc) modules to tandem cohesin (Coh) modules of a non-catalytic primary scaffoldin. In some cases, as exemplified by the cellulosome of the major cellulolytic ruminal bacterium Ruminococcus flavefaciens, primary scaffoldins bind to adaptor scaffoldins that further interact with the cell surface via anchoring scaffoldins, thereby increasing cellulosome complexity. Here we elucidate the structure of the unique Doc of R. flavefaciens FD-1 primary scaffoldin ScaA, bound to Coh 5 of the adaptor scaffoldin ScaB. The RfCohScaB5-DocScaA complex has an elliptical architecture similar to previously described complexes from a variety of ecological niches. ScaA Doc presents a single-binding mode, analogous to that described for the other two Coh-Doc specificities required for cellulosome assembly in R. flavefaciens. The exclusive reliance on a single-mode of Coh recognition contrasts with the majority of cellulosomes from other bacterial species described to date, where Docs contain two similar Coh-binding interfaces promoting a dual-binding mode. The discrete Coh-Doc interactions observed in ruminal cellulosomes suggest an adaptation to the exquisite properties of the rumen environment.

Integrating human and natural systems in community psychology: an ecological model of stewardship behavior.

PubMed

Moskell, Christine; Allred, Shorna Broussard

2013-03-01

Community psychology (CP) research on the natural environment lacks a theoretical framework for analyzing the complex relationship between human systems and the natural world. We introduce other academic fields concerned with the interactions between humans and the natural environment, including environmental sociology and coupled human and natural systems. To demonstrate how the natural environment can be included within CP's ecological framework, we propose an ecological model of urban forest stewardship action. Although ecological models of behavior in CP have previously modeled health behaviors, we argue that these frameworks are also applicable to actions that positively influence the natural environment. We chose the environmental action of urban forest stewardship because cities across the United States are planting millions of trees and increased citizen participation in urban tree planting and stewardship will be needed to sustain the benefits provided by urban trees. We used the framework of an ecological model of behavior to illustrate multiple levels of factors that may promote or hinder involvement in urban forest stewardship actions. The implications of our model for the development of multi-level ecological interventions to foster stewardship actions are discussed, as well as directions for future research to further test and refine the model.

Agent-based modeling in ecological economics.

PubMed

Heckbert, Scott; Baynes, Tim; Reeson, Andrew

2010-01-01

Interconnected social and environmental systems are the domain of ecological economics, and models can be used to explore feedbacks and adaptations inherent in these systems. Agent-based modeling (ABM) represents autonomous entities, each with dynamic behavior and heterogeneous characteristics. Agents interact with each other and their environment, resulting in emergent outcomes at the macroscale that can be used to quantitatively analyze complex systems. ABM is contributing to research questions in ecological economics in the areas of natural resource management and land-use change, urban systems modeling, market dynamics, changes in consumer attitudes, innovation, and diffusion of technology and management practices, commons dilemmas and self-governance, and psychological aspects to human decision making and behavior change. Frontiers for ABM research in ecological economics involve advancing the empirical calibration and validation of models through mixed methods, including surveys, interviews, participatory modeling, and, notably, experimental economics to test specific decision-making hypotheses. Linking ABM with other modeling techniques at the level of emergent properties will further advance efforts to understand dynamics of social-environmental systems.

Rats, cities, people, and pathogens: a systematic review and narrative synthesis of literature regarding the ecology of rat-associated zoonoses in urban centers.

PubMed

Himsworth, Chelsea G; Parsons, Kirbee L; Jardine, Claire; Patrick, David M

2013-06-01

Urban Norway and black rats (Rattus norvegicus and Rattus rattus) are the source of a number of pathogens responsible for significant human morbidity and mortality in cities around the world. These pathogens include zoonotic bacteria (Leptospira interrogans, Yersina pestis, Rickettsia typhi, Bartonella spp., Streptobacillus moniliformis), viruses (Seoul hantavirus), and parasites (Angiostrongylus cantonensis). A more complete understanding of the ecology of these pathogens in people and rats is critical for determining the public health risks associated with urban rats and for developing strategies to monitor and mitigate those risks. Although the ecology of rat-associated zoonoses is complex, due to the multiple ways in which rats, people, pathogens, vectors, and the environment may interact, common determinants of human disease can still be identified. This review summarizes the ecology of zoonoses associated with urban rats with a view to identifying similarities, critical differences, and avenues for further study.

Timing anthropogenic stressors to mitigate their impact on marine ecosystem resilience.

PubMed

Wu, Paul Pao-Yen; Mengersen, Kerrie; McMahon, Kathryn; Kendrick, Gary A; Chartrand, Kathryn; York, Paul H; Rasheed, Michael A; Caley, M Julian

2017-11-02

Better mitigation of anthropogenic stressors on marine ecosystems is urgently needed to address increasing biodiversity losses worldwide. We explore opportunities for stressor mitigation using whole-of-systems modelling of ecological resilience, accounting for complex interactions between stressors, their timing and duration, background environmental conditions and biological processes. We then search for ecological windows, times when stressors minimally impact ecological resilience, defined here as risk, recovery and resistance. We show for 28 globally distributed seagrass meadows that stressor scheduling that exploits ecological windows for dredging campaigns can achieve up to a fourfold reduction in recovery time and 35% reduction in extinction risk. Although the timing and length of windows vary among sites to some degree, global trends indicate favourable windows in autumn and winter. Our results demonstrate that resilience is dynamic with respect to space, time and stressors, varying most strongly with: (i) the life history of the seagrass genus and (ii) the duration and timing of the impacting stress.

The raison d'être of chemical ecology.

PubMed

Raguso, Robert A; Agrawal, Anurag A; Douglas, Angela E; Jander, Georg; Kessler, André; Poveda, Katja; Thaler, Jennifer S

2015-03-01

Chemical ecology is a mechanistic approach to understanding the causes and consequences of species interactions, distribution, abundance, and diversity. The promise of chemical ecology stems from its potential to provide causal mechanisms that further our understanding of ecological interactions and allow us to more effectively manipulate managed systems. Founded on the notion that all organisms use endogenous hormones and chemical compounds that mediate interactions, chemical ecology has flourished over the past 50 years since its origin. In this essay we highlight the breadth of chemical ecology, from its historical focus on pheromonal communication, plant-insect interactions, and coevolution to frontier themes including community and ecosystem effects of chemically mediated species interactions. Emerging approaches including the -omics, phylogenetic ecology, the form and function of microbiomes, and network analysis, as well as emerging challenges (e.g., sustainable agriculture and public health) are guiding current growth of this field. Nonetheless, the directions and approaches we advocate for the future are grounded in classic ecological theories and hypotheses that continue to motivate our broader discipline.

Beyond neutral and forbidden links: morphological matches and the assembly of mutualistic hawkmoth-plant networks.

PubMed

Sazatornil, Federico D; Moré, Marcela; Benitez-Vieyra, Santiago; Cocucci, Andrea A; Kitching, Ian J; Schlumpberger, Boris O; Oliveira, Paulo E; Sazima, Marlies; Amorim, Felipe W

2016-11-01

A major challenge in evolutionary ecology is to understand how co-evolutionary processes shape patterns of interactions between species at community level. Pollination of flowers with long corolla tubes by long-tongued hawkmoths has been invoked as a showcase model of co-evolution. Recently, optimal foraging models have predicted that there might be a close association between mouthparts' length and the corolla depth of the visited flowers, thus favouring trait convergence and specialization at community level. Here, we assessed whether hawkmoths more frequently pollinate plants with floral tube lengths similar to their proboscis lengths (morphological match hypothesis) against abundance-based processes (neutral hypothesis) and ecological trait mismatches constraints (forbidden links hypothesis), and how these processes structure hawkmoth-plant mutualistic networks from five communities in four biogeographical regions of South America. We found convergence in morphological traits across the five communities and that the distribution of morphological differences between hawkmoths and plants is consistent with expectations under the morphological match hypothesis in three of the five communities. In the two remaining communities, which are ecotones between two distinct biogeographical areas, interactions are better predicted by the neutral hypothesis. Our findings are consistent with the idea that diffuse co-evolution drives the evolution of extremely long proboscises and flower tubes, and highlight the importance of morphological traits, beyond the forbidden links hypothesis, in structuring interactions between mutualistic partners, revealing that the role of niche-based processes can be much more complex than previously known. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

The role of ecology in speciation by sexual selection: a systematic empirical review.

PubMed

Scordato, Elizabeth S C; Symes, Laurel B; Mendelson, Tamra C; Safran, Rebecca J

2014-01-01

Theoretical and empirical research indicates that sexual selection interacts with the ecological context in which mate choice occurs, suggesting that sexual and natural selection act together during the evolution of premating reproductive isolation. However, the relative importance of natural and sexual selection to speciation remains poorly understood. Here, we applied a recent conceptual framework for examining interactions between mate choice divergence and ecological context to a review of the empirical literature on speciation by sexual selection. This framework defines two types of interactions between mate choice and ecology: internal interactions, wherein natural and sexual selection jointly influence divergence in sexual signal traits and preferences, and external interactions, wherein sexual selection alone acts on traits and preferences but ecological context shapes the transmission efficacy of sexual signals. The objectives of this synthesis were 3-fold: to summarize the traits, ecological factors, taxa, and geographic contexts involved in studies of mate choice divergence; to analyze patterns of association between these variables; and to identify the most common types of interactions between mate choice and ecological factors. Our analysis revealed that certain traits are consistently associated with certain ecological factors. Moreover, among studies that examined a divergent sexually selected trait and an ecological factor, internal interactions were more common than external interactions. Trait-preference associations may thus frequently be subject to both sexual and natural selection in cases of divergent mate choice. Our results highlight the importance of interactions between sexual selection and ecology in mate choice divergence and suggest areas for future research. © The American Genetic Association. 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Study on planning and design of ecological tourist rural complex for the elderly

NASA Astrophysics Data System (ADS)

Han, Zhoulin; Jiang, Nan; He, Yunxiao; Long, Yanping

2018-03-01

In order to deal with the increasingly serious aging problem in China, a new model about serving the aged better needs to be explored. This paper puts forward the concept of ecological tourist rural complex for the elderly, a novel pattern that combining the rural retirement place with pastoral complex which is proposed recently. A concrete example of Deteng complex in Mianyang is given to explore the construction condition and planning approach. Three important aspects including pastoral, ecology, serving the aged are the core elements to develop ecological tourist rural complex for the elderly.

A multi-dimensional analysis of the upper Rio Grande-San Luis Valley social-ecological system

NASA Astrophysics Data System (ADS)

Mix, Ken

The Upper Rio Grande (URG), located in the San Luis Valley (SLV) of southern Colorado, is the primary contributor to streamflow to the Rio Grande Basin, upstream of the confluence of the Rio Conchos at Presidio, TX. The URG-SLV includes a complex irrigation-dependent agricultural social-ecological system (SES), which began development in 1852, and today generates more than 30% of the SLV revenue. The diversions of Rio Grande water for irrigation in the SLV have had a disproportionate impact on the downstream portion of the river. These diversions caused the flow to cease at Ciudad Juarez, Mexico in the late 1880s, creating international conflict. Similarly, low flows in New Mexico and Texas led to interstate conflict. Understanding changes in the URG-SLV that led to this event and the interactions among various drivers of change in the URG-SLV is a difficult task. One reason is that complex social-ecological systems are adaptive, contain feedbacks, emergent properties, cross-scale linkages, large-scale dynamics and non-linearities. Further, most analyses of SES to date have been qualitative, utilizing conceptual models to understand driver interactions. This study utilizes both qualitative and quantitative techniques to develop an innovative approach for analyzing driver interactions in the URG-SLV. Five drivers were identified for the URG-SLV social-ecological system: water (streamflow), water rights, climate, agriculture, and internal and external water policy. The drivers contained several longitudes (data aspect) relevant to the system, except water policy, for which only discreet events were present. Change point and statistical analyses were applied to the longitudes to identify quantifiable changes, to allow detection of cross-scale linkages between drivers, and presence of feedback cycles. Agricultural was identified as the driver signal. Change points for agricultural expansion defined four distinct periods: 1852--1923, 1924--1948, 1949--1978 and 1979--2007. Changes in streamflow, water allocations and water policy were observed in all agriculture periods. Cross-scale linkages were also evident between climate and streamflow; policy and water rights; and agriculture, groundwater pumping and streamflow.

Assessing mismatches in ecosystem services proficiency across the urban fabric of Porto (Portugal): The influence of structural and socioeconomic variables

Treesearch

Marisa S. Graça; João F. Gonçalves; Paulo J.M. Alves; David J. Nowak; Robert Hoehn; Alexis Ellis; Paulo Farinha-Marques; Mario Cunha

2017-01-01

According to UN estimates, it is expected that the world population living in cities will exceed 66% in 2050 (United Nations, 2014). The complex and intense interaction of ecological and socioeconomic systems shaping cities has highlighted the need to foster an interdisciplinary approach to urban issues integrating Natural and Social Sciences (Alberti et al., 2003)....

Oak savanna restoration in central Iowa: Assessing indicators of forest health for ecological monitoring (PROJECT NC-F-04-02)

Treesearch

Heidi Asbjornsen; Lars Brudvig

2013-01-01

Savanna ecosystems were once a dominant feature of the Midwestern Corn Belt Plains ecoregion, occurring within the dynamic boundary between prairies to the west and forests to the east, and maintained in the landscape by complex interactions between fire, climate, topography, and human activities (Anderson 1998). Characterized by their continuous understory layer and...

Improving the assessment of predator functional responses by considering alternate prey and predator interactions.

PubMed

Chan, K; Boutin, S; Hossie, T J; Krebs, C J; O'Donoghue, M; Murray, D L

2017-07-01

To improve understanding of the complex and variable patterns of predator foraging behavior in natural systems, it is critical to determine how density-dependent predation and predator hunting success are mediated by alternate prey or predator interference. Despite considerable theory and debate seeking to place predator-prey interactions in a more realistic context, few empirical studies have quantified the role of alternate prey or intraspecific interactions on predator-prey dynamics. We assessed functional responses of two similarly sized, sympatric carnivores, lynx (Lynx canadensis) and coyotes (Canis latrans), foraging on common primary (snowshoe hares; Lepus americanus) and alternate (red squirrels; Tamiasciurus hudsonicus) prey in a natural system. Lynx exhibited a hyperbolic prey-dependent response to changes in hare density, which is characteristic of predators relying primarily on a single prey species. In contrast, the lynx-squirrel response was found to be linear ratio dependent, or inversely dependent on hare density. The coyote-hare and coyote-squirrel interactions also were linear and influenced by predator density. We explain these novel results by apparent use of spatial and temporal refuges by prey, and the likelihood that predators commonly experience interference and lack of satiation when foraging. Our study provides empirical support from a natural predator-prey system that (1) predation rate may not be limited at high prey densities when prey are small or rarely captured; (2) interference competition may influence the predator functional response; and (3) predator interference has a variable role across different prey types. Ultimately, distinct functional responses of predators to different prey types illustrates the complexity associated with predator-prey interactions in natural systems and highlights the need to investigate predator behavior and predation rate in relation to the broader ecological community. © 2017 by the Ecological Society of America.

Professional Training for TRADOC Environmental and Natural Resource Professionals. Volume 2. Source Listings

DTIC Science & Technology

1991-05-01

Plant Biology); Carol Augspurger 376 INSTITUTION; COOPERATOR University of Illinois, Urbana ( Ecology , Ethology & Evolution ...43 Ph.D. 33 33 33 1 STRENGTHS AND SPECIALTIES Subject Matter Strengths: Biogeography, community ecology , vertebrate ecology , plant /insect interactions ... ecology , population ecology of small mammals, avian ecology , plant /animal interactions . Formal Teaching/Research Arrangements With Other

A Social-Cognitive-Ecological Framework for Understanding the Impact of Exposure to Persistent Ethnic-Political Violence on Children’s Psychosocial Adjustment

PubMed Central

Dubow, Eric F.; Huesmann, L. Rowell; Boxer, Paul

2009-01-01

In this article, we describe a theoretical framework for understanding how persistent and extreme exposure to ethnic-political conflict and violence interacts with cognitive, emotional, and self processes to influence children’s psychosocial adjustment. Three recent strands of theorizing guide our approach. First, we focus on how observational and social learning processes combine to influence the development of social-cognitive structures and processes that affect behavior. Second, we focus on the role of developing self and identity processes in shaping the child’s interactions with the world and the consequences of those interactions. Third, we build on the complex systems perspective on development and assume that human development can only be understood accurately by examining how the multiple contexts affecting children and the adults in their lives interact to moderate biosocial factors which predispose individuals to develop in certain directions. We review the recent empirical literature on children’s exposure to ethnic-political violence and we apply the social-cognitive-ecological framework to the empirical findings in this literature. Finally, we propose future directions for research and clinical implications derived from this framework. PMID:19430904

A social-cognitive-ecological framework for understanding the impact of exposure to persistent ethnic-political violence on children's psychosocial adjustment.

PubMed

Dubow, Eric F; Huesmann, L Rowell; Boxer, Paul

2009-06-01

In this article, we describe a theoretical framework for understanding how persistent and extreme exposure to ethnic-political conflict and violence interacts with cognitive, emotional, and self processes to influence children's psychosocial adjustment. Three recent strands of theorizing guide our approach. First, we focus on how observational and social learning processes combine to influence the development of social-cognitive structures and processes that affect behavior. Second, we focus on the role of developing self and identity processes in shaping the child's interactions with the world and the consequences of those interactions. Third, we build on the complex systems perspective on development and assume that human development can only be understood accurately by examining how the multiple contexts affecting children and the adults in their lives interact to moderate biosocial factors which predispose individuals to develop in certain directions. We review the recent empirical literature on children's exposure to ethnic-political violence and we apply the social-cognitive-ecological framework to the empirical findings in this literature. Finally, we propose future directions for research and clinical implications derived from this framework.

Pathways from marine protected area design and management to ecological success

PubMed Central

2015-01-01

Using an international dataset compiled from 121 sites in 87 marine protected areas (MPAs) globally (Edgar et al., 2014), I assessed how various configurations of design and management conditions affected MPA ecological performance, measured in terms of fish species richness and biomass. The set-theoretic approach used Boolean algebra to identify pathways that combined up to five ‘NEOLI’ (No-take, Enforced, Old, Large, Isolated) conditions and that were sufficient for achieving positive, and negative, ecological outcomes. Ecological isolation was overwhelming the most important condition affecting ecological outcomes but Old and Large were also conditions important for achieving high levels of biomass among large fishes (jacks, groupers, sharks). Solution coverage was uniformly low (<0.35) for all models of positive ecological performance suggesting the presence of numerous other conditions and pathways to ecological success that did not involve the NEOLI conditions. Solution coverage was higher (>0.50) for negative results (i.e., the absence of high biomass) among the large commercially-exploited fishes, implying asymmetries in how MPAs may rebuild populations on the one hand and, on the other, protect against further decline. The results revealed complex interactions involving MPA design, implementation, and management conditions that affect MPA ecological performance. In general terms, the presence of no-take regulations and effective enforcement were insufficient to ensure MPA effectiveness on their own. Given the central role of ecological isolation in securing ecological benefits from MPAs, site selection in the design phase appears critical for success. PMID:26644975

Asymmetric ecological conditions favor Red-Queen type of continued evolution over stasis.

PubMed

Nordbotten, Jan Martin; Stenseth, Nils C

2016-02-16

Four decades ago, Leigh Van Valen presented the Red Queen's hypothesis to account for evolution of species within a multispecies ecological community [Van Valen L (1973) Evol Theory 1(1):1-30]. The overall conclusion of Van Valen's analysis was that evolution would continue even in the absence of abiotic perturbations. Stenseth and Maynard Smith presented in 1984 [Stenseth NC, Maynard Smith J (1984) Evolution 38(4):870-880] a model for the Red Queen's hypothesis showing that both Red-Queen type of continuous evolution and stasis could result from a model with biotically driven evolution. However, although that contribution demonstrated that both evolutionary outcomes were possible, it did not identify which ecological conditions would lead to each of these evolutionary outcomes. Here, we provide, using a simple, yet general population-biologically founded eco-evolutionary model, such analytically derived conditions: Stasis will predominantly emerge whenever the ecological system contains only symmetric ecological interactions, whereas both Red-Queen and stasis type of evolution may result if the ecological interactions are asymmetrical, and more likely so with increasing degree of asymmetry in the ecological system (i.e., the more trophic interactions, host-pathogen interactions, and the like there are [i.e., +/- type of ecological interactions as well as asymmetric competitive (-/-) and mutualistic (+/+) ecological interactions]). In the special case of no between-generational genetic variance, our results also predict dynamics within these types of purely ecological systems.

Social Interface Model: Theorizing Ecological Post-Delivery Processes for Intervention Effects.

PubMed

Pettigrew, Jonathan; Segrott, Jeremy; Ray, Colter D; Littlecott, Hannah

2018-01-03

Successful prevention programs depend on a complex interplay among aspects of the intervention, the participant, the specific intervention setting, and the broader set of contexts with which a participant interacts. There is a need to theorize what happens as participants bring intervention ideas and behaviors into other life-contexts, and theory has not yet specified how social interactions about interventions may influence outcomes. To address this gap, we use an ecological perspective to develop the social interface model. This paper presents the key components of the model and its potential to aid the design and implementation of prevention interventions. The model is predicated on the idea that intervention message effectiveness depends not only on message aspects but also on the participants' adoption and adaptation of the message vis-à-vis their social ecology. The model depicts processes by which intervention messages are received and enacted by participants through social processes occurring within and between relevant microsystems. Mesosystem interfaces (negligible interface, transference, co-dependence, and interdependence) can facilitate or detract from intervention effects. The social interface model advances prevention science by theorizing that practitioners can create better quality interventions by planning for what occurs after interventions are delivered.

Ecological and genetic interactions between cyanobacteria and viruses in a low-oxygen mat community inferred through metagenomics and metatranscriptomics.

PubMed

Voorhies, Alexander A; Eisenlord, Sarah D; Marcus, Daniel N; Duhaime, Melissa B; Biddanda, Bopaiah A; Cavalcoli, James D; Dick, Gregory J

2016-02-01

Metagenomic and metatranscriptomic sequencing was conducted on cyanobacterial mats of the Middle Island Sinkhole (MIS), Lake Huron. Metagenomic data from 14 samples collected over 5 years were used to reconstruct genomes of two genotypes of a novel virus, designated PhV1 type A and PhV1 type B. Both viral genotypes encode and express nblA, a gene involved in degrading phycobilisomes, which are complexes of pigmented proteins that harvest light for photosynthesis. Phylogenetic analysis indicated that the viral-encoded nblA is derived from the host cyanobacterium, Phormidium MIS-PhA. The cyanobacterial host also has two complete CRISPR (clustered regularly interspaced short palindromic repeats) systems that serve as defence mechanisms for bacteria and archaea against viruses and plasmids. One 45 bp CRISPR spacer from Phormidium had 100% nucleotide identity to PhV1 type B, but this region was absent from PhV1 type A. Transcripts from PhV1 and the Phormidium CRISPR loci were detected in all six metatranscriptomic data sets (three during the day and three at night), indicating that both are transcriptionally active in the environment. These results reveal ecological and genetic interactions between viruses and cyanobacteria at MIS, highlighting the value of parallel analysis of viruses and hosts in understanding ecological interactions in natural communities. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Toward an Integrative Understanding of Social Behavior: New Models and New Opportunities

PubMed Central

Blumstein, Daniel T.; Ebensperger, Luis A.; Hayes, Loren D.; Vásquez, Rodrigo A.; Ahern, Todd H.; Burger, Joseph Robert; Dolezal, Adam G.; Dosmann, Andy; González-Mariscal, Gabriela; Harris, Breanna N.; Herrera, Emilio A.; Lacey, Eileen A.; Mateo, Jill; McGraw, Lisa A.; Olazábal, Daniel; Ramenofsky, Marilyn; Rubenstein, Dustin R.; Sakhai, Samuel A.; Saltzman, Wendy; Sainz-Borgo, Cristina; Soto-Gamboa, Mauricio; Stewart, Monica L.; Wey, Tina W.; Wingfield, John C.; Young, Larry J.

2010-01-01

Social interactions among conspecifics are a fundamental and adaptively significant component of the biology of numerous species. Such interactions give rise to group living as well as many of the complex forms of cooperation and conflict that occur within animal groups. Although previous conceptual models have focused on the ecological causes and fitness consequences of variation in social interactions, recent developments in endocrinology, neuroscience, and molecular genetics offer exciting opportunities to develop more integrated research programs that will facilitate new insights into the physiological causes and consequences of social variation. Here, we propose an integrative framework of social behavior that emphasizes relationships between ultimate-level function and proximate-level mechanism, thereby providing a foundation for exploring the full diversity of factors that underlie variation in social interactions, and ultimately sociality. In addition to identifying new model systems for the study of human psychopathologies, this framework provides a mechanistic basis for predicting how social behavior will change in response to environmental variation. We argue that the study of non-model organisms is essential for implementing this integrative model of social behavior because such species can be studied simultaneously in the lab and field, thereby allowing integration of rigorously controlled experimental manipulations with detailed observations of the ecological contexts in which interactions among conspecifics occur. PMID:20661457

Genome-culture coevolution promotes rapid divergence of killer whale ecotypes.

PubMed

Foote, Andrew D; Vijay, Nagarjun; Ávila-Arcos, María C; Baird, Robin W; Durban, John W; Fumagalli, Matteo; Gibbs, Richard A; Hanson, M Bradley; Korneliussen, Thorfinn S; Martin, Michael D; Robertson, Kelly M; Sousa, Vitor C; Vieira, Filipe G; Vinař, Tomáš; Wade, Paul; Worley, Kim C; Excoffier, Laurent; Morin, Phillip A; Gilbert, M Thomas P; Wolf, Jochen B W

2016-05-31

Analysing population genomic data from killer whale ecotypes, which we estimate have globally radiated within less than 250,000 years, we show that genetic structuring including the segregation of potentially functional alleles is associated with socially inherited ecological niche. Reconstruction of ancestral demographic history revealed bottlenecks during founder events, likely promoting ecological divergence and genetic drift resulting in a wide range of genome-wide differentiation between pairs of allopatric and sympatric ecotypes. Functional enrichment analyses provided evidence for regional genomic divergence associated with habitat, dietary preferences and post-zygotic reproductive isolation. Our findings are consistent with expansion of small founder groups into novel niches by an initial plastic behavioural response, perpetuated by social learning imposing an altered natural selection regime. The study constitutes an important step towards an understanding of the complex interaction between demographic history, culture, ecological adaptation and evolution at the genomic level.

Genome-culture coevolution promotes rapid divergence of killer whale ecotypes

PubMed Central

Foote, Andrew D.; Vijay, Nagarjun; Ávila-Arcos, María C.; Baird, Robin W.; Durban, John W.; Fumagalli, Matteo; Gibbs, Richard A.; Hanson, M. Bradley; Korneliussen, Thorfinn S.; Martin, Michael D.; Robertson, Kelly M.; Sousa, Vitor C.; Vieira, Filipe G.; Vinař, Tomáš; Wade, Paul; Worley, Kim C.; Excoffier, Laurent; Morin, Phillip A.; Gilbert, M. Thomas P.; Wolf, Jochen B.W.

2016-01-01

Analysing population genomic data from killer whale ecotypes, which we estimate have globally radiated within less than 250,000 years, we show that genetic structuring including the segregation of potentially functional alleles is associated with socially inherited ecological niche. Reconstruction of ancestral demographic history revealed bottlenecks during founder events, likely promoting ecological divergence and genetic drift resulting in a wide range of genome-wide differentiation between pairs of allopatric and sympatric ecotypes. Functional enrichment analyses provided evidence for regional genomic divergence associated with habitat, dietary preferences and post-zygotic reproductive isolation. Our findings are consistent with expansion of small founder groups into novel niches by an initial plastic behavioural response, perpetuated by social learning imposing an altered natural selection regime. The study constitutes an important step towards an understanding of the complex interaction between demographic history, culture, ecological adaptation and evolution at the genomic level. PMID:27243207

Strategies and ecological roles of algicidal bacteria.

PubMed

Meyer, Nils; Bigalke, Arite; Kaulfuß, Anett; Pohnert, Georg

2017-11-01

In both freshwater and marine ecosystems, phytoplankton are the most dominant primary producers, contributing substantially to aquatic food webs. Algicidal bacteria that can associate to microalgae from the phytoplankton have the capability to control the proliferation and even to lyse them. These bacteria thus play an important role in shaping species composition in pelagic environments. In this review, we discuss and categorise strategies used by algicidal bacteria for the attack on microalgae. We highlight the complex regulation of algicidal activity and defence responses that govern alga-bacteria interactions. We also discuss how algicidal bacteria impact algal physiology and metabolism and survey the existing algicidal metabolites and enzymes. The review illustrates that the ecological role of algicidal bacteria is not yet fully understood and critically discusses the challenges in obtaining ecologically relevant data. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Interactions of microplastic debris throughout the marine ecosystem.

PubMed

Galloway, Tamara S; Cole, Matthew; Lewis, Ceri

2017-04-20

Marine microscopic plastic (microplastic) debris is a modern societal issue, illustrating the challenge of balancing the convenience of plastic in daily life with the prospect of causing ecological harm by careless disposal. Here we develop the concept of microplastic as a complex, dynamic mixture of polymers and additives, to which organic material and contaminants can successively bind to form an 'ecocorona', increasing the density and surface charge of particles and changing their bioavailability and toxicity. Chronic exposure to microplastic is rarely lethal, but can adversely affect individual animals, reducing feeding and depleting energy stores, with knock-on effects for fecundity and growth. We explore the extent to which ecological processes could be impacted, including altered behaviours, bioturbation and impacts on carbon flux to the deep ocean. We discuss how microplastic compares with other anthropogenic pollutants in terms of ecological risk, and consider the role of science and society in tackling this global issue in the future.

UV-vis spectroscopy and colorimetric models for detecting anthocyanin-metal complexes in plants: An overview of in vitro and in vivo techniques.

PubMed

Fedenko, Volodymyr S; Shemet, Sergiy A; Landi, Marco

2017-05-01

Although anthocyanin (ACN) biosynthesis is one of the best studied pathways of secondary metabolism in plants, the possible physiological and ecological role(s) of these pigments continue to intrigue scientists. Like other dihydroxy B-ring substituted flavonoids, ACNs have an ability to bind metal and metalloid ions, a property that has been exploited for a variety of purposes. For example, the metal binding ability may be used to stabilize ACNs from plant food sources, or to modify their colors for using them as food colorants. The complexation of metals with cyanidin derivatives can also be used as a simple, sensitive, cheap, and rapid method for determination concentrations of several metals in biological and environmental samples using UV-vis spectroscopy. Far less information is available on the ecological significance of ACN-metal complexes in plant-environment interactions. Metalloanthocyanins (protocyanin, nemophilin, commelinin, protodelphin, cyanosalvianin) are involved in the copigmentation phenomenon that leads to blue-pigmented petals, which may facilitate specific plant-pollinator interactions. ACN-metal formation and compartmentation into the vacuole has also been proposed to be part of an orchestrated detoxification mechanism in plants which experience metal/metalloid excess. However, investigations into ACN-metal interactions in plant biology may be limited because of the complexity of the analytical techniques required. To address this concern, here we describe simple methods for the detection of ACN-metal both in vitro and in vivo using UV-vis spectroscopy and colorimetric models. In particular, the use of UV-vis spectra, difference absorption spectra, and colorimetry techniques will be described for in vitro determination of ACN-metal features, whereas reflectance spectroscopy and colorimetric parameters related to CIE L * a * b * and CIE XYZ systems will be detailed for in vivo analyses. In this way, we hope to make this high-informative tool more accessible to plant physiologists and ecologists. Copyright © 2017 Elsevier GmbH. All rights reserved.

Proceedings of the Agent 2002 Conference on Social Agents : Ecology, Exchange, and Evolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macal, C., ed.; Sallach, D., ed.

2003-04-10

Welcome to the ''Proceedings'' of the third in a series of agent simulation conferences cosponsored by Argonne National Laboratory and The University of Chicago. The theme of this year's conference, ''Social Agents: Ecology, Exchange and Evolution'', was selected to foster the exchange of ideas on some of the most important social processes addressed by agent simulation models, namely: (1) The translation of ecology and ecological constraints into social dynamics; (2) The role of exchange processes, including the peer dependencies they create; and (3) The dynamics by which, and the attractor states toward which, social processes evolve. As stated in themore » ''Call for Papers'', throughout the social sciences, the simulation of social agents has emerged as an innovative and powerful research methodology. The promise of this approach, however, is accompanied by many challenges. First, modeling complexity in agents, environments, and interactions is non-trivial, and these representations must be explored and assessed systematically. Second, strategies used to represent complexities are differentially applicable to any particular problem space. Finally, to achieve sufficient generality, the design and experimentation inherent in agent simulation must be coupled with social and behavioral theory. Agent 2002 provides a forum for reviewing the current state of agent simulation scholarship, including research designed to address such outstanding issues. This year's conference introduces an extensive range of domains, models, and issues--from pre-literacy to future projections, from ecology to oligopolistic markets, and from design to validation. Four invited speakers highlighted major themes emerging from social agent simulation.« less

The Hidden World within Plants: Ecological and Evolutionary Considerations for Defining Functioning of Microbial Endophytes

PubMed Central

van Overbeek, Leonard S.; Berg, Gabriele; Pirttilä, Anna Maria; Compant, Stéphane; Campisano, Andrea; Döring, Matthias; Sessitsch, Angela

2015-01-01

SUMMARY All plants are inhabited internally by diverse microbial communities comprising bacterial, archaeal, fungal, and protistic taxa. These microorganisms showing endophytic lifestyles play crucial roles in plant development, growth, fitness, and diversification. The increasing awareness of and information on endophytes provide insight into the complexity of the plant microbiome. The nature of plant-endophyte interactions ranges from mutualism to pathogenicity. This depends on a set of abiotic and biotic factors, including the genotypes of plants and microbes, environmental conditions, and the dynamic network of interactions within the plant biome. In this review, we address the concept of endophytism, considering the latest insights into evolution, plant ecosystem functioning, and multipartite interactions. PMID:26136581

Complex foraging ecology of the red harvester ant and its effect on the soil seed bank

NASA Astrophysics Data System (ADS)

Luna, Pedro; García-Chávez, Juan Héctor; Dáttilo, Wesley

2018-01-01

Granivory is an important interaction in the arid and semi-arid zones of the world, since seeds form an abundant and nutritious resource in these areas. While species of the genus Pogonomyrmex have been studied in detail as seed predators, their impact on seed abundance in the soil has not yet been explored in sufficient depth. We studied the impact of the harvesting activities of the ant Pogonomyrmex barbatus on seed abundance in the soil of the Zapotitlán valley, Mexico. We found that P. barbatus activity significantly impacts the abundance of seeds in the soil, which is lower in the sites where P. barbatus forages than it is in sites with no recorded foraging. We also found that P. barbatus distributes intact seeds of three tree species, two of which are nurse plants, and could consequently be promoting the establishment of these species. Using tools derived from graph theory, we observed that the ant-seed interactions exhibit a nested pattern; where more depredated seed species seem to be the more spatially abundant in the environment. This study illustrates the complex foraging ecology of the harvester ant P. barbatus and elucidates its effect on the soil seed bank in a semi-arid environment.

Asymmetric ecological conditions favor Red-Queen type of continued evolution over stasis

PubMed Central

Nordbotten, Jan Martin; Stenseth, Nils C.

2016-01-01

Four decades ago, Leigh Van Valen presented the Red Queen’s hypothesis to account for evolution of species within a multispecies ecological community [Van Valen L (1973) Evol Theory 1(1):1–30]. The overall conclusion of Van Valen’s analysis was that evolution would continue even in the absence of abiotic perturbations. Stenseth and Maynard Smith presented in 1984 [Stenseth NC, Maynard Smith J (1984) Evolution 38(4):870–880] a model for the Red Queen’s hypothesis showing that both Red-Queen type of continuous evolution and stasis could result from a model with biotically driven evolution. However, although that contribution demonstrated that both evolutionary outcomes were possible, it did not identify which ecological conditions would lead to each of these evolutionary outcomes. Here, we provide, using a simple, yet general population-biologically founded eco-evolutionary model, such analytically derived conditions: Stasis will predominantly emerge whenever the ecological system contains only symmetric ecological interactions, whereas both Red-Queen and stasis type of evolution may result if the ecological interactions are asymmetrical, and more likely so with increasing degree of asymmetry in the ecological system (i.e., the more trophic interactions, host–pathogen interactions, and the like there are [i.e., +/− type of ecological interactions as well as asymmetric competitive (−/−) and mutualistic (+/+) ecological interactions]). In the special case of no between-generational genetic variance, our results also predict dynamics within these types of purely ecological systems. PMID:26831108

Ticks and Tick-Borne Infections: Complex Ecology, Agents, and Host Interactions.

PubMed

Wikel, Stephen K

2018-06-20

Ticks transmit the most diverse array of infectious agents of any arthropod vector. Both ticks and the microbes they transmit are recognized as significant threats to human and veterinary public health. This article examines the potential impacts of climate change on the distribution of ticks and the infections they transmit; the emergence of novel tick-borne pathogens, increasing geographic range and incidence of tick-borne infections; and advances in the characterization of tick saliva mediated modulation of host defenses and the implications of those interactions for transmission, establishment, and control of tick infestation and tick-borne infectious agents.

Limitations of a metabolic network-based reverse ecology method for inferring host-pathogen interactions.

PubMed

Takemoto, Kazuhiro; Aie, Kazuki

2017-05-25

Host-pathogen interactions are important in a wide range of research fields. Given the importance of metabolic crosstalk between hosts and pathogens, a metabolic network-based reverse ecology method was proposed to infer these interactions. However, the validity of this method remains unclear because of the various explanations presented and the influence of potentially confounding factors that have thus far been neglected. We re-evaluated the importance of the reverse ecology method for evaluating host-pathogen interactions while statistically controlling for confounding effects using oxygen requirement, genome, metabolic network, and phylogeny data. Our data analyses showed that host-pathogen interactions were more strongly influenced by genome size, primary network parameters (e.g., number of edges), oxygen requirement, and phylogeny than the reserve ecology-based measures. These results indicate the limitations of the reverse ecology method; however, they do not discount the importance of adopting reverse ecology approaches altogether. Rather, we highlight the need for developing more suitable methods for inferring host-pathogen interactions and conducting more careful examinations of the relationships between metabolic networks and host-pathogen interactions.

Evolutionary Ecology of Multitrophic Interactions between Plants, Insect Herbivores and Entomopathogens.

PubMed

Shikano, Ikkei

2017-06-01

Plants play an important role in the interactions between insect herbivores and their pathogens. Since the seminal review by Cory and Hoover (2006) on plant-mediated effects on insect-pathogen interactions, considerable progress has been made in understanding the complexity of these tritrophic interactions. Increasing interest in the areas of nutritional and ecological immunology over the last decade have revealed that plant primary and secondary metabolites can influence the outcomes of insect-pathogen interactions by altering insect immune functioning and physical barriers to pathogen entry. Some insects use plant secondary chemicals and nutrients to prevent infections (prophylactic medication) and medicate to limit the severity of infections (therapeutic medication). Recent findings suggest that there may be selectable plant traits that enhance entomopathogen efficacy, suggesting that entomopathogens could potentially impose selection pressure on plant traits that improve both pathogen and plant fitness. Moreover, plants in nature are inhabited by diverse communities of microbes, in addition to entomopathogens, some of which can trigger immune responses in insect herbivores. Plants are also shared by numerous other herbivorous arthropods with different modes of feeding that can trigger different defensive responses in plants. Some insect symbionts and gut microbes can degrade ingested defensive phytochemicals and be orally secreted onto wounded plant tissue during herbivory to alter plant defenses. Since non-entomopathogenic microbes and other arthropods are likely to influence the outcomes of plant-insect-entomopathogen interactions, I discuss a need to consider these multitrophic interactions within the greater web of species interactions.

A socio-ecological analysis of Ethiopian immigrants' interactions with the Israeli healthcare system and its policy and service implications.

PubMed

Shtarkshall, Ronny A; Baynesan, Fassil; Feldman, Becca S

2009-10-01

Despite receiving full medical care and many social services, many Ethiopian immigrants in Israel feel frustrated, and even alienated, by the care they receive. This study uses a qualitative approach to explore the obstacles Ethiopian immigrants face regarding effective health seeking behavior and optimal interactions with healthcare providers in Israel. We gained a three-cornered perspective by conducting semi-structured interviews with healthcare providers, immigrants, and interpreters who mediate between the two. An ecological system or socio-ecological model guided the data analysis. It allowed organizing the varied and complex relationship between the factors that influence healthcare delivery and receipt among this population. The advanced analysis of our results delineated four themes which we grouped into two domains: the cultural divide and the interpreters. Within each of these themes, we explored influences on health or healthcare at each level of the socio-ecological model. We demonstrated that the problems surrounding health seeking behaviors and receiving treatment stem mainly from a cultural divide. This cultural incongruity and its effects are apparent at multiple levels of the ecological model and must be recognized and addressed programmatically at these levels. Necessary program and service modifications include that cultural mediation become an integral part of health personnel's training for healthcare delivery and a necessary criterion for good practices. We recommend that professionals from within the health system be trained to act as interpreters. Lastly, the integration of traditional healers into the allopathic health system should be considered. These modifications require a system-wide change in policy, structure of services, and practices.

Assessment and Mmanagement of North American horseshoe crab populations, with emphasis on a multispecies framework for Delaware Bay, U.S.A. populations: Chapter 24

USGS Publications Warehouse

Millard, Michael J.; Sweka, John A.; McGowan, Conor P.; Smith, David R.

2015-01-01

The horseshoe crab fishery on the US Atlantic coast represents a compelling fishery management story for many reasons, including ecological complexity, health and human safety ramifications, and socio-economic conflicts. Knowledge of stock status and assessment and monitoring capabilities for the species have increased greatly in the last 15 years and permitted managers to make more informed harvest recommendations. Incorporating the bioenergetics needs of migratory shorebirds, which feed on horseshoe crab eggs, into the management framework for horseshoe crabs was identified as a goal, particularly in the Delaware Bay region where the birds and horseshoe crabs exhibit an important ecological interaction. In response, significant effort was invested in studying the population dynamics, migration ecology, and the ecologic relationship of a key migratory shorebird, the Red Knot, to horseshoe crabs. A suite of models was developed that linked Red Knot populations to horseshoe crab populations through a mass gain function where female spawning crab abundance determined what proportion of the migrating Red Knot population reached a critical body mass threshold. These models were incorporated in an adaptive management framework wherein optimal harvest decisions for horseshoe crab are recommended based on several resource-based and value-based variables and thresholds. The current adaptive framework represents a true multispecies management effort where additional data over time are employed to improve the predictive models and reduce parametric uncertainty. The possibility of increasing phenologic asynchrony between the two taxa in response to climate change presents a potential challenge to their ecologic interaction in Delaware Bay.

The complexity underlying invasiveness precludes the identification of invasive traits: A comparative study of invasive and non-invasive heterocarpic Atriplex congeners

PubMed Central

Doudová, Jana; Douda, Jan; Mandák, Bohumil

2017-01-01

Heterocarpy enables species to effectively spread under unfavourable conditions by producing two or more types of fruit differing in ecological characteristics. Although it is frequent in annuals occupying disturbed habitats that are vulnerable to invasion, there is still a lack of congeneric studies addressing the importance of heterocarpy for species invasion success. We compared two pairs of heterocarpic Atriplex species, each of them comprising one invasive and one non-invasive non-native congener. In two common garden experiments, we (i) simulated the influence of different levels of nutrients and population density on plants grown from different types of fruits and examined several traits that are generally positively associated with invasion success, and (ii) grew plants in a replacement series experiment to evaluate resource partitioning between them and to compare their competitive ability. We found that specific functional traits or competitiveness of species cannot explain the invasiveness of Atriplex species, indicating that species invasiveness involves more complex interactions of traits that are important only in certain ecological contexts, i.e. in specific environmental conditions and only some habitats. Interestingly, species trait differences related to invasion success were found between plants growing from the ecologically most contrasting fruit types. We suggest that fruit types differing in ecological behaviour may be essential in the process of invasion or in the general spreading of heterocarpic species, as they either the maximize population growth (type C fruit) or enhance the chance of survival of new populations (type A fruit). Congeners offer the best available methodical framework for comparing traits among phylogenetically closely related invasive and non-invasive species. However, as indicated by our results, this approach is unlikely to reveal invasive traits because of the complexity underlying invasiveness. PMID:28445514

Social-ecological innovation in remote mountain areas: Adaptive responses of forest-dependent communities to the challenges of a changing world.

PubMed

Melnykovych, Mariana; Nijnik, Maria; Soloviy, Ihor; Nijnik, Albert; Sarkki, Simo; Bihun, Yurij

2018-02-01

To better understand how constantly changing human-environment interactions could be better organized to respond to current challenges, we examined the Ukrainian Carpathians as an example case of complex forest social-ecological systems (FSES). We did it by interviewing diverse and relevant local stakeholder (N=450). In particular, we strived to: i) outline how people and nature are linked and interact in coupled FSES; ii) examine the preferences of stakeholders on the forests and associated ecosystem services (ES); iii) map key drivers threatening well-being of FSES and iv) identify potential responses to address the challenges at a local scale. To answer these questions we followed a mixed method route by integrating qualitative (participatory) and quantitative data collection and analyses, with further application of a Driving Force-Pressure-State-Impact-Response (DPSIR) framework in combination with the ES approach in order to assess benefits, threats to these benefits, and responses regarding the studied FSES. We found that the key benefit from FSES is timber and non-wood forest products (like berries and mushrooms), but also various regulating services were ranked highly by respondents. To explore social-ecological innovation, with potential responses of forest-dependent communities to challenges they face, we employed a commonly used assumption that governance must fit to the particular characteristics of FSES in order to enable sustainability. For the particular case of the Ukrainian Carpathians, we identified and discussed the following five nonconformities or "misfits" threatening sustainability: 1) Spatial misfit in legislation; 2) Poor contextualization; 3) Trap of the single ES; 4) Participatory misfit; and 5) Robbing the commons. By conceptualizing those key threats, we proposed responses for sustainability. The findings contributed to an advanced understanding of complex FSES, their key challenges and potential solutions in order to secure well-being of people and nature in coupled social-ecological systems, in the conditions of a changing world. Copyright © 2017 Elsevier B.V. All rights reserved.

Predator diversity and environmental change modify the strengths of trophic and nontrophic interactions.

PubMed

Sentis, Arnaud; Gémard, Charlène; Jaugeon, Baptiste; Boukal, David S

2017-07-01

Understanding the dependence of species interaction strengths on environmental factors and species diversity is crucial to predict community dynamics and persistence in a rapidly changing world. Nontrophic (e.g. predator interference) and trophic components together determine species interaction strengths, but the effects of environmental factors on these two components remain largely unknown. This impedes our ability to fully understand the links between environmental drivers and species interactions. Here, we used a dynamical modelling framework based on measured predator functional responses to investigate the effects of predator diversity, prey density, and temperature on trophic and nontrophic interaction strengths within a freshwater food web. We found that (i) species interaction strengths cannot be predicted from trophic interactions alone, (ii) nontrophic interaction strengths vary strongly among predator assemblages, (iii) temperature has opposite effects on trophic and nontrophic interaction strengths, and (iv) trophic interaction strengths decrease with prey density, whereas the dependence of nontrophic interaction strengths on prey density is concave up. Interestingly, the qualitative impacts of temperature and prey density on the strengths of trophic and nontrophic interactions were independent of predator identity, suggesting a general pattern. Our results indicate that taking multiple environmental factors and the nonlinearity of density-dependent species interactions into account is an important step towards a better understanding of the effects of environmental variations on complex ecological communities. The functional response approach used in this study opens new avenues for (i) the quantification of the relative importance of the trophic and nontrophic components in species interactions and (ii) a better understanding how environmental factors affect these interactions and the dynamics of ecological communities. © 2016 John Wiley & Sons Ltd.

A Semiarid Long-Term Hydrologic Observatory at the Continental Scale: The Upper Río Grande Basin

NASA Astrophysics Data System (ADS)

Hogan, J. F.; Vivoni, E. R.; Bowman, R. S.; Coonrod, J.; Thomson, B. M.; Samani, Z.; Ferre, P. T.; Phillips, F. M.; Rango, A.; Rasmussen, R.; Springer, E. P.; Small, E. E.

2004-12-01

Water availability is critical in arid and semiarid regions, which comprise 35 percent of the land area of the globe. In the Southwestern US, climate variability and landscape heterogeneity lead to strong gradients in hydrological processes, which in turn impact land-atmosphere interactions, ecological dynamics, biogeochemical cycles and geomorphic change. This complexity presents a fundamental challenge to our understanding of hydrology, one that is best addressed through long-term, systematic field and remote-sensing observations and numerical-model investigations. In this poster, we will present our plans to study the interaction of climate-landscape-vegetation and water using a nested set of instrumented sites within the Upper Río Grande, a continental-scale semiarid watershed. This complex watershed extends from the snow-dominated headwater basins in San Juan Mountains of southern Colorado, through the Chihuahuan Desert in New Mexico, Texas and Mexico, to the desert valley alluvial basins southeast of El Paso, Texas. As part of the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) plan for a network of Long-Term Hydrologic Observatories (LTHOs), the Upper Río Grande would represent the combination of mountain landscapes, semiarid to arid alluvial basin aquifers and riparian corridors that are characteristic of the Western United States. We will describe existing hydrologic, ecologic and atmospheric measurement infrastructure in the watershed and discuss plans for integrating these into a coherent network that provides a core set of scientific data products for the hydrologic community. Data products generated by the Upper Río Grande LTHO will also aid in the testing of coupled numerical models of the atmosphere-surface-groundwater system applied at high resolution over the region. The Upper Río Grande presents unique opportunities to test hydrologic hypotheses concerning surface water-groundwater interactions and their control on runoff response, solute transport and reactivity, and riparian ecological communities

On the dangers of model complexity without ecological justification in species distribution modeling

Treesearch

David M. Bell; Daniel R. Schlaepfer

2016-01-01

Although biogeographic patterns are the product of complex ecological processes, the increasing com-plexity of correlative species distribution models (SDMs) is not always motivated by ecological theory,but by model fit. The validity of model projections, such as shifts in a species’ climatic niche, becomesquestionable particularly during extrapolations, such as for...

The ecology, evolution, impacts and management of host-parasite interactions of marine molluscs.

PubMed

Coen, Loren D; Bishop, Melanie J

2015-10-01

Molluscs are economically and ecologically important components of aquatic ecosystems. In addition to supporting valuable aquaculture and wild-harvest industries, their populations determine the structure of benthic communities, cycling of nutrients, serve as prey resources for higher trophic levels and, in some instances, stabilize shorelines and maintain water quality. This paper reviews existing knowledge of the ecology of host-parasite interactions involving marine molluscs, with a focus on gastropods and bivalves. It considers the ecological and evolutionary impacts of molluscan parasites on their hosts and vice versa, and on the communities and ecosystems in which they are a part, as well as disease management and its ecological impacts. An increasing number of case studies show that disease can have important effects on marine molluscs, their ecological interactions and ecosystem services, at spatial scales from centimeters to thousands of kilometers and timescales ranging from hours to years. In some instances the cascading indirect effects arising from parasitic infection of molluscs extend well beyond the temporal and spatial scales at which molluscs are affected by disease. In addition to the direct effects of molluscan disease, there can be large indirect impacts on marine environments resulting from strategies, such as introduction of non-native species and selective breeding for disease resistance, put in place to manage disease. Much of our understanding of impacts of molluscan diseases on the marine environment has been derived from just a handful of intensively studied marine parasite-host systems, namely gastropod-trematode, cockle-trematode, and oyster-protistan interactions. Understanding molluscan host-parasite dynamics is of growing importance because: (1) expanding aquaculture; (2) current and future climate change; (3) movement of non-native species; and (4) coastal development are modifying molluscan disease dynamics, ultimately leading to complex relationships between diseases and cultivated and natural molluscan populations. Further, in some instances the enhancement or restoration of valued ecosystem services may be contingent on management of molluscan disease. The application of newly emerging molecular tools and remote sensing techniques to the study of molluscan disease will be important in identifying how changes at varying spatial and temporal scales with global change are modifying host-parasite systems. Copyright © 2015 Elsevier Inc. All rights reserved.

Bringing the ecosystem services concept into marine management decisions, supporting ecosystems-based management.

NASA Astrophysics Data System (ADS)

Tweddle, J. F.; Byg, A.; Davies, I.; Gubbins, M.; Irvine, K.; Kafas, A.; Kenter, J.; MacDonald, A.; Murray, R. B. O.; Potts, T.; Slater, A. M.; Wright, K.; Scott, B. E.

2016-02-01

The marine environment is under increasing use, putting pressure on marine ecosystems and increasing competition for space. New activities (e.g. renewable energy developments), evolving marine policies (e.g. implementation of marine protected areas), and climate change may drive changes in biodiversity and resulting ecosystem services (ES) that society and business utilise from coastal and marine systems. A process is needed that integrates ecological assessment of changes with stakeholder perceptions and valuation of ES, whilst balancing ease of application with the ability to deal with complex social-economic-ecological issues. The project "Cooperative participatory assessment of the impact of renewable technology on ecosystem services: CORPORATES" involved natural and social scientists, law and policy experts, and marine managers, with the aim of promoting more integrated decision making using ES concepts in marine management. CORPORATES developed a process to bring ES concepts into stakeholders' awareness. The interactive process, involving 2 workshops, employs interludes of knowledge exchange by experts on ecological processes underpinning ES and on law and policy. These enable mapping of benefits linked to activities, participatory system modelling, and deliberation of policy impacts on different sectors. The workshops were attended by industry representatives, regulatory/advisory partners, and other stakeholders (NGOs, SMEs, recreationalists, local government). Mixed sector groups produced new insights into links between activities and ES, and highlighted cross-sector concerns. Here we present the aspects of the process that successfully built shared understanding between industry and stakeholders of inter-linkages and interactions between ES, benefits, activities, and economic and cultural values. These methods provide an ES-based decision-support model for exchanging societal-ecological knowledge and providing stakeholder interaction in marine planning, supporting ecosystem-based management.

Bringing the ecosystem services concept into marine management decisions, supporting ecosystems-based management.

NASA Astrophysics Data System (ADS)

Tweddle, J. F.; Byg, A.; Davies, I.; Gubbins, M.; Irvine, K.; Kafas, A.; Kenter, J.; MacDonald, A.; Murray, R. B. O.; Potts, T.; Slater, A. M.; Wright, K.; Scott, B. E.

2016-12-01

The marine environment is under increasing use, putting pressure on marine ecosystems and increasing competition for space. New activities (e.g. renewable energy developments), evolving marine policies (e.g. implementation of marine protected areas), and climate change may drive changes in biodiversity and resulting ecosystem services (ES) that society and business utilise from coastal and marine systems. A process is needed that integrates ecological assessment of changes with stakeholder perceptions and valuation of ES, whilst balancing ease of application with the ability to deal with complex social-economic-ecological issues. The project "Cooperative participatory assessment of the impact of renewable technology on ecosystem services: CORPORATES" involved natural and social scientists, law and policy experts, and marine managers, with the aim of promoting more integrated decision making using ES concepts in marine management. CORPORATES developed a process to bring ES concepts into stakeholders' awareness. The interactive process, involving 2 workshops, employs interludes of knowledge exchange by experts on ecological processes underpinning ES and on law and policy. These enable mapping of benefits linked to activities, participatory system modelling, and deliberation of policy impacts on different sectors. The workshops were attended by industry representatives, regulatory/advisory partners, and other stakeholders (NGOs, SMEs, recreationalists, local government). Mixed sector groups produced new insights into links between activities and ES, and highlighted cross-sector concerns. Here we present the aspects of the process that successfully built shared understanding between industry and stakeholders of inter-linkages and interactions between ES, benefits, activities, and economic and cultural values. These methods provide an ES-based decision-support model for exchanging societal-ecological knowledge and providing stakeholder interaction in marine planning, supporting ecosystem-based management.

Master stability functions reveal diffusion-driven pattern formation in networks

NASA Astrophysics Data System (ADS)

Brechtel, Andreas; Gramlich, Philipp; Ritterskamp, Daniel; Drossel, Barbara; Gross, Thilo

2018-03-01

We study diffusion-driven pattern formation in networks of networks, a class of multilayer systems, where different layers have the same topology, but different internal dynamics. Agents are assumed to disperse within a layer by undergoing random walks, while they can be created or destroyed by reactions between or within a layer. We show that the stability of homogeneous steady states can be analyzed with a master stability function approach that reveals a deep analogy between pattern formation in networks and pattern formation in continuous space. For illustration, we consider a generalized model of ecological meta-food webs. This fairly complex model describes the dispersal of many different species across a region consisting of a network of individual habitats while subject to realistic, nonlinear predator-prey interactions. In this example, the method reveals the intricate dependence of the dynamics on the spatial structure. The ability of the proposed approach to deal with this fairly complex system highlights it as a promising tool for ecology and other applications.

Integrating succession and community assembly perspectives

PubMed Central

Chang, Cynthia; HilleRisLambers, Janneke

2016-01-01

Succession and community assembly research overlap in many respects, such as through their focus on how ecological processes like dispersal, environmental filters, and biotic interactions influence community structure. Indeed, many recent advances have been made by successional studies that draw on modern analytical techniques introduced by contemporary community assembly studies. However, community assembly studies generally lack a temporal perspective, both on how the forces structuring communities might change over time and on how historical contingency (e.g. priority effects and legacy effects) and complex transitions (e.g. threshold effects) might alter community trajectories. We believe a full understanding of the complex interacting processes that shape community dynamics across large temporal scales can best be achieved by combining concepts, tools, and study systems into an integrated conceptual framework that draws upon both succession and community assembly theory. PMID:27785355

The next step in health behavior research: the need for ecological moderation analyses - an application to diet and physical activity at childcare.

PubMed

Gubbels, Jessica S; Van Kann, Dave Hh; de Vries, Nanne K; Thijs, Carel; Kremers, Stef Pj

2014-04-17

The ecological perspective holds that human behavior depends on the interaction of different environmental factors and personal characteristics, but it lacks validation and operationalization. In the current paper, an ecological view was adopted to examine the interactive impact of several ecological systems on children's dietary intake and physical activity at childcare or similar facilities. The ecological view was operationalized into three types of interaction: 1) interaction between types of childcare environment (physical, social, political, economic); 2) interaction between micro-systems (the childcare and home environment) in meso-systems; and 3) interaction between childcare environment and child characteristics. The predictive value of each of these interactions was tested based on a systematic review of the literature. Several studies support the hypothesis that the influence of the childcare environment on children's physical activity and diet is moderated by child characteristics (age, gender), but interaction between environmental types as well as between micro-systems is hardly examined in the field of behavioral nutrition and physical activity. Qualitative studies and general child development research provide some valuable insights, but we advocate quantitative research adopting an ecological perspective on environmental influences. Empirical studies operationalizing a true ecological view on diet and physical activity are scarce. Theorizing and assessment of interaction is advocated to become common practice rather than an exception in behavioral nutrition and physical activity research, in order to move the field forward.

The next step in health behavior research: the need for ecological moderation analyses - an application to diet and physical activity at childcare

PubMed Central

2014-01-01

Background The ecological perspective holds that human behavior depends on the interaction of different environmental factors and personal characteristics, but it lacks validation and operationalization. In the current paper, an ecological view was adopted to examine the interactive impact of several ecological systems on children’s dietary intake and physical activity at childcare or similar facilities. The ecological view was operationalized into three types of interaction: 1) interaction between types of childcare environment (physical, social, political, economic); 2) interaction between micro-systems (the childcare and home environment) in meso-systems; and 3) interaction between childcare environment and child characteristics. The predictive value of each of these interactions was tested based on a systematic review of the literature. Discussion Several studies support the hypothesis that the influence of the childcare environment on children’s physical activity and diet is moderated by child characteristics (age, gender), but interaction between environmental types as well as between micro-systems is hardly examined in the field of behavioral nutrition and physical activity. Qualitative studies and general child development research provide some valuable insights, but we advocate quantitative research adopting an ecological perspective on environmental influences. Summary Empirical studies operationalizing a true ecological view on diet and physical activity are scarce. Theorizing and assessment of interaction is advocated to become common practice rather than an exception in behavioral nutrition and physical activity research, in order to move the field forward. PMID:24742167

Ecologic Niche Modeling and Potential Reservoirs for Chagas Disease, Mexico.

PubMed Central

Sánchez-Cordero, Victor; Ben Beard, C.; Ramsey, Janine M.

2002-01-01

Ecologic niche modeling may improve our understanding of epidemiologically relevant vector and parasite-reservoir distributions. We used this tool to identify host relationships of Triatoma species implicated in transmission of Chagas disease. Associations have been documented between the protracta complex (Triatoma: Triatominae: Reduviidae) with packrat species (Neotoma spp.), providing an excellent case study for the broader challenge of developing hypotheses of association. Species pairs that were identified coincided exactly with those in previous studies, suggesting that local interactions between Triatoma and Neotoma species and subspecies have implications at a geographic level. Nothing is known about sylvatic associates of T. barberi, which are considered the primary Chagas vector in Mexico; its geographic distribution coincided closely with that of N. mexicana, suggesting interaction. The presence of the species was confirmed in two regions where it had been predicted but not previously collected. This approach may help in identifying Chagas disease risk areas, planning vector-control strategies, and exploring parasite-reservoir associations for other emerging diseases. PMID:12095431

Developing predictive systems models to address complexity and relevance for ecological risk assessment.

PubMed

Forbes, Valery E; Calow, Peter

2013-07-01

Ecological risk assessments (ERAs) are not used as well as they could be in risk management. Part of the problem is that they often lack ecological relevance; that is, they fail to grasp necessary ecological complexities. Adding realism and complexity can be difficult and costly. We argue that predictive systems models (PSMs) can provide a way of capturing complexity and ecological relevance cost-effectively. However, addressing complexity and ecological relevance is only part of the problem. Ecological risk assessments often fail to meet the needs of risk managers by not providing assessments that relate to protection goals and by expressing risk in ratios that cannot be weighed against the costs of interventions. Once more, PSMs can be designed to provide outputs in terms of value-relevant effects that are modulated against exposure and that can provide a better basis for decision making than arbitrary ratios or threshold values. Recent developments in the modeling and its potential for implementation by risk assessors and risk managers are beginning to demonstrate how PSMs can be practically applied in risk assessment and the advantages that doing so could have. Copyright © 2013 SETAC.

Conceptualising the interactive effects of climate change and biological invasions on subarctic freshwater fish.

PubMed

Rolls, Robert J; Hayden, Brian; Kahilainen, Kimmo K

2017-06-01

Climate change and species invasions represent key threats to global biodiversity. Subarctic freshwaters are sentinels for understanding both stressors because the effects of climate change are disproportionately strong at high latitudes and invasion of temperate species is prevalent. Here, we summarize the environmental effects of climate change and illustrate the ecological responses of freshwater fishes to these effects, spanning individual, population, community and ecosystem levels. Climate change is modifying hydrological cycles across atmospheric, terrestrial and aquatic components of subarctic ecosystems, causing increases in ambient water temperature and nutrient availability. These changes affect the individual behavior, habitat use, growth and metabolism, alter population spawning and recruitment dynamics, leading to changes in species abundance and distribution, modify food web structure, trophic interactions and energy flow within communities and change the sources, quantity and quality of energy and nutrients in ecosystems. Increases in temperature and its variability in aquatic environments underpin many ecological responses; however, altered hydrological regimes, increasing nutrient inputs and shortened ice cover are also important drivers of climate change effects and likely contribute to context-dependent responses. Species invasions are a complex aspect of the ecology of climate change because the phenomena of invasion are both an effect and a driver of the ecological consequences of climate change. Using subarctic freshwaters as an example, we illustrate how climate change can alter three distinct aspects of species invasions: (1) the vulnerability of ecosystems to be invaded, (2) the potential for species to spread and invade new habitats, and (3) the subsequent ecological effects of invaders. We identify three fundamental knowledge gaps focused on the need to determine (1) how environmental and landscape characteristics influence the ecological impact of climate change, (2) the separate and combined effects of climate and non-native invading species and (3) the underlying ecological processes or mechanisms responsible for changes in patterns of biodiversity.

Rapid evolution of hosts begets species diversity at the cost of intraspecific diversity.

PubMed

Frickel, Jens; Theodosiou, Loukas; Becks, Lutz

2017-10-17

Ecosystems are complex food webs in which multiple species interact and ecological and evolutionary processes continuously shape populations and communities. Previous studies on eco-evolutionary dynamics have shown that the presence of intraspecific diversity affects community structure and function, and that eco-evolutionary feedback dynamics can be an important driver for its maintenance. Within communities, feedbacks are, however, often indirect, and they can feed back over many generations. Here, we studied eco-evolutionary feedbacks in evolving communities over many generations and compared two-species systems (virus-host and prey-predator) with a more complex three-species system (virus-host-predator). Both indirect density- and trait-mediated effects drove the dynamics in the complex system, where host-virus coevolution facilitated coexistence of predator and virus, and where coexistence, in return, lowered intraspecific diversity of the host population. Furthermore, ecological and evolutionary dynamics were significantly altered in the three-species system compared with the two-species systems. We found that the predator slowed host-virus coevolution in the complex system and that the virus' effect on the overall population dynamics was negligible when the three species coexisted. Overall, we show that a detailed understanding of the mechanism driving eco-evolutionary feedback dynamics is necessary for explaining trait and species diversity in communities, even in communities with only three species.

Termite hindguts and the ecology of microbial communities in the sequencing age.

PubMed

Tai, Vera; Keeling, Patrick J

2013-01-01

Advances in high-throughput nucleic acid sequencing have improved our understanding of microbial communities in a number of ways. Deeper sequence coverage provides the means to assess diversity at the resolution necessary to recover ecological and biogeographic patterns, and at the same time single-cell genomics provides detailed information about the interactions between members of a microbial community. Given the vastness and complexity of microbial ecosystems, such analyses remain challenging for most environments, so greater insight can also be drawn from analysing less dynamic ecosystems. Here, we outline the advantages of one such environment, the wood-digesting hindgut communities of termites and cockroaches, and how it is a model to examine and compare both protist and bacterial communities. Beyond the analysis of diversity, our understanding of protist community ecology will depend on using statistically sound sampling regimes at biologically relevant scales, transitioning from discovery-based to experimental ecology, incorporating single-cell microbiology and other data sources, and continued development of analytical tools. © 2013 The Author(s) Journal of Eukaryotic Microbiology © 2013 International Society of Protistologists.

Social-ecological resilience and geomorphic systems

NASA Astrophysics Data System (ADS)

Chaffin, Brian C.; Scown, Murray

2018-03-01

Governance of coupled social-ecological systems (SESs) and the underlying geomorphic processes that structure and alter Earth's surface is a key challenge for global sustainability amid the increasing uncertainty and change that defines the Anthropocene. Social-ecological resilience as a concept of scientific inquiry has contributed to new understandings of the dynamics of change in SESs, increasing our ability to contextualize and implement governance in these systems. Often, however, the importance of geomorphic change and geomorphological knowledge is somewhat missing from processes employed to inform SES governance. In this contribution, we argue that geomorphology and social-ecological resilience research should be integrated to improve governance toward sustainability. We first provide definitions of engineering, ecological, community, and social-ecological resilience and then explore the use of these concepts within and alongside geomorphology in the literature. While ecological studies often consider geomorphology as an important factor influencing the resilience of ecosystems and geomorphological studies often consider the engineering resilience of geomorphic systems of interest, very few studies define and employ a social-ecological resilience framing and explicitly link the concept to geomorphic systems. We present five key concepts-scale, feedbacks, state or regime, thresholds and regime shifts, and humans as part of the system-which we believe can help explicitly link important aspects of social-ecological resilience inquiry and geomorphological inquiry in order to strengthen the impact of both lines of research. Finally, we discuss how these five concepts might be used to integrate social-ecological resilience and geomorphology to better understand change in, and inform governance of, SESs. To compound these dynamics of resilience, complex systems are nested and cross-scale interactions from smaller and larger scales relative to the system of interest can play formative roles during periods of collapse and reorganization. Large- and small-scale disturbances as well as large-scale system memory/capacity and small-scale innovation can have significant impacts on the trajectory of a reorganizing system (Gunderson and Holling, 2002; Chaffin and Gunderson, 2016). Attempts to measure the property of ecological resilience across complex systems amounts to attempts to measure the persistence of system-controlling variables, including processes, parameters, and important feedbacks, when the system is exposed to varying degrees of disturbance (Folke, 2016).

Coevolutionary diversification creates nested-modular structure in phage–bacteria interaction networks

PubMed Central

Beckett, Stephen J.; Williams, Hywel T. P.

2013-01-01

Phage and their bacterial hosts are the most diverse and abundant biological entities in the oceans, where their interactions have a major impact on marine ecology and ecosystem function. The structure of interaction networks for natural phage–bacteria communities offers insight into their coevolutionary origin. At small phylogenetic scales, observed communities typically show a nested structure, in which both hosts and phages can be ranked by their range of resistance and infectivity, respectively. A qualitatively different multi-scale structure is seen at larger phylogenetic scales; a natural assemblage sampled from the Atlantic Ocean displays large-scale modularity and local nestedness within each module. Here, we show that such ‘nested-modular’ interaction networks can be produced by a simple model of host–phage coevolution in which infection depends on genetic matching. Negative frequency-dependent selection causes diversification of hosts (to escape phages) and phages (to track their evolving hosts). This creates a diverse community of bacteria and phage, maintained by kill-the-winner ecological dynamics. When the resulting communities are visualized as bipartite networks of who infects whom, they show the nested-modular structure characteristic of the Atlantic sample. The statistical significance and strength of this observation varies depending on whether the interaction networks take into account the density of the interacting strains, with implications for interpretation of interaction networks constructed by different methods. Our results suggest that the apparently complex community structures associated with marine bacteria and phage may arise from relatively simple coevolutionary origins. PMID:24516719

Hidden drivers of low-dose pharmaceutical pollutant mixtures revealed by the novel GSA-QHTS screening method

PubMed Central

Rodea-Palomares, Ismael; Gonzalez-Pleiter, Miguel; Gonzalo, Soledad; Rosal, Roberto; Leganes, Francisco; Sabater, Sergi; Casellas, Maria; Muñoz-Carpena, Rafael; Fernández-Piñas, Francisca

2016-01-01

The ecological impacts of emerging pollutants such as pharmaceuticals are not well understood. The lack of experimental approaches for the identification of pollutant effects in realistic settings (that is, low doses, complex mixtures, and variable environmental conditions) supports the widespread perception that these effects are often unpredictable. To address this, we developed a novel screening method (GSA-QHTS) that couples the computational power of global sensitivity analysis (GSA) with the experimental efficiency of quantitative high-throughput screening (QHTS). We present a case study where GSA-QHTS allowed for the identification of the main pharmaceutical pollutants (and their interactions), driving biological effects of low-dose complex mixtures at the microbial population level. The QHTS experiments involved the integrated analysis of nearly 2700 observations from an array of 180 unique low-dose mixtures, representing the most complex and data-rich experimental mixture effect assessment of main pharmaceutical pollutants to date. An ecological scaling-up experiment confirmed that this subset of pollutants also affects typical freshwater microbial community assemblages. Contrary to our expectations and challenging established scientific opinion, the bioactivity of the mixtures was not predicted by the null mixture models, and the main drivers that were identified by GSA-QHTS were overlooked by the current effect assessment scheme. Our results suggest that current chemical effect assessment methods overlook a substantial number of ecologically dangerous chemical pollutants and introduce a new operational framework for their systematic identification. PMID:27617294

a System Dynamics Approach for Looking at the Human and Environmental Interactions of Community-Based Irrigation Systems in New Mexico

NASA Astrophysics Data System (ADS)

Ochoa, C. G.; Tidwell, V. C.

2012-12-01

In the arid southwestern United States community water management systems have adapted to cope with climate variability and with socio-cultural and economic changes that have occurred since the establishment of these systems more than 300 years ago. In New Mexico, the community-based irrigation systems were established by Spanish settlers and have endured climate variability in the form of low levels of precipitation and have prevailed over important socio-political changes including the transfer of territory between Spain and Mexico, and between Mexico and the United States. Because of their inherent nature of integrating land and water use with society involvement these community-based systems have multiple and complex economic, ecological, and cultural interactions. Current urban population growth and more variable climate conditions are adding pressure to the survival of these systems. We are conducting a multi-disciplinary research project that focuses on characterizing these intrinsically complex human and natural interactions in three community-based irrigation systems in northern New Mexico. We are using a system dynamics approach to integrate different hydrological, ecological, socio-cultural and economic aspects of these three irrigation systems. Coupled with intensive field data collection, we are building a system dynamics model that will enable us to simulate important linkages and interactions between environmental and human elements occurring in each of these water management systems. We will test different climate variability and population growth scenarios and the expectation is that we will be able to identify critical tipping points of these systems. Results from this model can be used to inform policy recommendations relevant to the environment and to urban and agricultural land use planning in the arid southwestern United States.

Impact of two specialist insect herbivores on reproduction of horse nettle, Solanum carolinense.

PubMed

Wise, Michael J; Sacchi, Christopher F

1996-10-01

The frequency of coevolution as a process of strong mutual interaction between a single plant and herbivore species has been questioned in light of more commonly observed, complex relationships between a plant and a suite of herbivore species. Despite recognition of the possibility of diffuse coevolution, relatively few studies have examined ecological responses of plants to herbivores in complex associations. We studied the impact of two specialist herbivores, the horse nettle beetle, Leptinotarsa juncta, and the eggplant flea beetle, Epitrix fuscula, on reproduction of their host, Solanum carolinense. Our study involved field and controlled-environment experimental tests of the impact on sexual and potential asexual reproduction of attack by individuals of the two herbivore species, individually and in combination. Field tests demonstrated that under normal levels of phytophagous insect attack, horse nettle plants experienced a reduction in fruit production of more than 75% compared with plants from which insects were excluded. In controlled-environment experiments using enclosure-exclosure cages, the horse nettle's two principal herbivores, the flea beetle and the horse nettle beetle, caused decreases in sexual reproduction similar to those observed in the field, and a reduction in potential asexual reproduction, represented by root biomass. Attack by each herbivore reduced the numbers of fruits produced, and root growth, when feeding in isolation. When both species were feeding together, fruit production, but not root growth, was lower than when either beetle species fed alone. Ecological interactions between horse nettle and its two primary herbivores necessary for diffuse coevolution to occur were evident from an overall analysis of the statistical interactions between the two herbivores for combined assessment of fruit and vegetative traits. For either of these traits alone, the interactions necessary to promote diffuse coevolution apparently were lacking.

Neutral Community Dynamics and the Evolution of Species Interactions.

PubMed

Coelho, Marco Túlio P; Rangel, Thiago F

2018-04-01

A contemporary goal in ecology is to determine the ecological and evolutionary processes that generate recurring structural patterns in mutualistic networks. One of the great challenges is testing the capacity of neutral processes to replicate observed patterns in ecological networks, since the original formulation of the neutral theory lacks trophic interactions. Here, we develop a stochastic-simulation neutral model adding trophic interactions to the neutral theory of biodiversity. Without invoking ecological differences among individuals of different species, and assuming that ecological interactions emerge randomly, we demonstrate that a spatially explicit multitrophic neutral model is able to capture the recurrent structural patterns of mutualistic networks (i.e., degree distribution, connectance, nestedness, and phylogenetic signal of species interactions). Nonrandom species distribution, caused by probabilistic events of migration and speciation, create nonrandom network patterns. These findings have broad implications for the interpretation of niche-based processes as drivers of ecological networks, as well as for the integration of network structures with demographic stochasticity.

Marine reserves as linked social-ecological systems.

PubMed

Pollnac, Richard; Christie, Patrick; Cinner, Joshua E; Dalton, Tracey; Daw, Tim M; Forrester, Graham E; Graham, Nicholas A J; McClanahan, Timothy R

2010-10-26

Marine reserves are increasingly recognized as having linked social and ecological dynamics. This study investigates how the ecological performance of 56 marine reserves throughout the Philippines, Caribbean, and Western Indian Ocean (WIO) is related to both reserve design features and the socioeconomic characteristics in associated coastal communities. Ecological performance was measured as fish biomass in the reserve relative to nearby areas. Of the socioeconomic variables considered, human population density and compliance with reserve rules had the strongest effects on fish biomass, but the effects of these variables were region specific. Relationships between population density and the reserve effect on fish biomass were negative in the Caribbean, positive in the WIO, and not detectable in the Philippines. Differing associations between population density and reserve effectiveness defy simple explanation but may depend on human migration to effective reserves, depletion of fish stocks outside reserves, or other social factors that change with population density. Higher levels of compliance reported by resource users was related to higher fish biomass in reserves compared with outside, but this relationship was only statistically significant in the Caribbean. A heuristic model based on correlations between social, cultural, political, economic, and other contextual conditions in 127 marine reserves showed that high levels of compliance with reserve rules were related to complex social interactions rather than simply to enforcement of reserve rules. Comparative research of this type is important for uncovering the complexities surrounding human dimensions of marine reserves and improving reserve management.

Climate change and the past, present, and future of biotic interactions.

PubMed

Blois, Jessica L; Zarnetske, Phoebe L; Fitzpatrick, Matthew C; Finnegan, Seth

2013-08-02

Biotic interactions drive key ecological and evolutionary processes and mediate ecosystem responses to climate change. The direction, frequency, and intensity of biotic interactions can in turn be altered by climate change. Understanding the complex interplay between climate and biotic interactions is thus essential for fully anticipating how ecosystems will respond to the fast rates of current warming, which are unprecedented since the end of the last glacial period. We highlight episodes of climate change that have disrupted ecosystems and trophic interactions over time scales ranging from years to millennia by changing species' relative abundances and geographic ranges, causing extinctions, and creating transient and novel communities dominated by generalist species and interactions. These patterns emerge repeatedly across disparate temporal and spatial scales, suggesting the possibility of similar underlying processes. Based on these findings, we identify knowledge gaps and fruitful areas for research that will further our understanding of the effects of climate change on ecosystems.

Network succession reveals the importance of competition in response to emulsified vegetable oil amendment for uranium bioremediation.

PubMed

Deng, Ye; Zhang, Ping; Qin, Yujia; Tu, Qichao; Yang, Yunfeng; He, Zhili; Schadt, Christopher Warren; Zhou, Jizhong

2016-01-01

Discerning network interactions among different species/populations in microbial communities has evoked substantial interests in recent years, but little information is available about temporal dynamics of microbial network interactions in response to environmental perturbations. Here, we modified the random matrix theory-based network approach to discern network succession in groundwater microbial communities in response to emulsified vegetable oil (EVO) amendment for uranium bioremediation. Groundwater microbial communities from one control and seven monitor wells were analysed with a functional gene array (GeoChip 3.0), and functional molecular ecological networks (fMENs) at different time points were reconstructed. Our results showed that the network interactions were dramatically altered by EVO amendment. Dynamic and resilient succession was evident: fairly simple at the initial stage (Day 0), increasingly complex at the middle period (Days 4, 17, 31), most complex at Day 80, and then decreasingly complex at a later stage (140-269 days). Unlike previous studies in other habitats, negative interactions predominated in a time-series fMEN, suggesting strong competition among different microbial species in the groundwater systems after EVO injection. Particularly, several keystone sulfate-reducing bacteria showed strong negative interactions with their network neighbours. These results provide mechanistic understanding of the decreased phylogenetic diversity during environmental perturbations. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Network succession reveals the importance of competition in response to emulsified vegetable oil amendment for uranium bioremediation: Competition in bioremediation system

DOE PAGES

Deng, Ye; Zhang, Ping; Qin, Yujia; ...

2015-08-11

When trying to discern network interactions among different species/populations in microbial communities interests have been evoked in recent years, but little information is available about temporal dynamics of microbial network interactions in response to environmental perturbations. We modified the random matrix theory-based network approach to discern network succession in groundwater microbial communities in response to emulsified vegetable oil (EVO) amendment for uranium bioremediation. Groundwater microbial communities from one control and seven monitor wells were analysed with a functional gene array (GeoChip 3.0), and functional molecular ecological networks (fMENs) at different time points were reconstructed. Our results showed that the networkmore » interactions were dramatically altered by EVO amendment. Dynamic and resilient succession was evident: fairly simple at the initial stage (Day 0), increasingly complex at the middle period (Days 4, 17, 31), most complex at Day 80, and then decreasingly complex at a later stage (140–269 days). Unlike previous studies in other habitats, negative interactions predominated in a time-series fMEN, suggesting strong competition among different microbial species in the groundwater systems after EVO injection. In particular, several keystone sulfate-reducing bacteria showed strong negative interactions with their network neighbours. These results provide mechanistic understanding of the decreased phylogenetic diversity during environmental perturbations.« less

Language Program as Ecology: A Perspective for Leadership

ERIC Educational Resources Information Center

Pennington, Martha C.; Hoekje, Barbara J.

2010-01-01

A language program is a delicate and intricate system of interacting resources or components, which, like a biological ecology, is in a constant state of evolution and change. The interactive system making up the program's internal culture is connected ecologically to the external environment. The ecological model is introduced as a useful…

Zoonoses, One Health and complexity: wicked problems and constructive conflict.

PubMed

Waltner-Toews, David

2017-07-19

Infectious zoonoses emerge from complex interactions among social and ecological systems. Understanding this complexity requires the accommodation of multiple, often conflicting, perspectives and narratives, rooted in different value systems and temporal-spatial scales. Therefore, to be adaptive, successful and sustainable, One Health approaches necessarily entail conflicts among observers, practitioners and scholars. Nevertheless, these integrative approaches have, both implicitly and explicitly, tended to marginalize some perspectives and prioritize others, resulting in a kind of technocratic tyranny. An important function of One Health approaches should be to facilitate and manage those conflicts, rather than to impose solutions.This article is part of the themed issue 'One Health for a changing world: zoonoses, ecosystems and human well-being'. © 2017 The Authors.

Advances in animal ecology from 3D ecosystem mapping with LiDAR

NASA Astrophysics Data System (ADS)

Davies, A.; Asner, G. P.

2015-12-01

The advent and recent advances of Light Detection and Ranging (LiDAR) have enabled accurate measurement of 3D ecosystem structure. Although the use of LiDAR data is widespread in vegetation science, it has only recently (< 14 years) been applied to animal ecology. Despite such recent application, LiDAR has enabled new insights in the field and revealed the fundamental importance of 3D ecosystem structure for animals. We reviewed the studies to date that have used LiDAR in animal ecology, synthesising the insights gained. Structural heterogeneity is most conducive to increased animal richness and abundance, and increased complexity of vertical vegetation structure is more positively influential than traditionally measured canopy cover, which produces mixed results. However, different taxonomic groups interact with a variety of 3D canopy traits and some groups with 3D topography. LiDAR technology can be applied to animal ecology studies in a wide variety of environments to answer an impressive array of questions. Drawing on case studies from vastly different groups, termites and lions, we further demonstrate the applicability of LiDAR and highlight new understanding, ranging from habitat preference to predator-prey interactions, that would not have been possible from studies restricted to field based methods. We conclude with discussion of how future studies will benefit by using LiDAR to consider 3D habitat effects in a wider variety of ecosystems and with more taxa to develop a better understanding of animal dynamics.

Stability and generalization in seed dispersal networks: a case study of frugivorous fish in Neotropical wetlands.

PubMed

Correa, Sandra Bibiana; Arujo, Joisiane K; Penha, Jerry; Nunes da Cunha, Catia; Bobier, Karen E; Anderson, Jill T

2016-08-31

When species within guilds perform similar ecological roles, functional redundancy can buffer ecosystems against species loss. Using data on the frequency of interactions between fish and fruit, we assessed whether co-occurring frugivores provide redundant seed dispersal services in three species-rich Neotropical wetlands. Our study revealed that frugivorous fishes have generalized diets; however, large-bodied fishes had greater seed dispersal breadth than small species, in some cases, providing seed dispersal services not achieved by smaller fish species. As overfishing disproportionately affects big fishes, the extirpation of these species could cause larger secondary extinctions of plant species than the loss of small specialist frugivores. To evaluate the consequences of frugivore specialization for network stability, we extracted data from 39 published seed dispersal networks of frugivorous birds, mammals and fish (our networks) across ecosystems. Our analysis of interaction frequencies revealed low frugivore specialization and lower nestedness than analyses based on binary data (presence-absence of interactions). In that case, ecosystems may be resilient to loss of any given frugivore. However, robustness to frugivore extinction declines with specialization, such that networks composed primarily of specialist frugivores are highly susceptible to the loss of generalists. In contrast with analyses of binary data, recently developed algorithms capable of modelling interaction strengths provide opportunities to enhance our understanding of complex ecological networks by accounting for heterogeneity of frugivore-fruit interactions. © 2016 The Author(s).

Stability and generalization in seed dispersal networks: a case study of frugivorous fish in Neotropical wetlands

PubMed Central

Arujo, Joisiane K.; Penha, Jerry; Nunes da Cunha, Catia

2016-01-01

When species within guilds perform similar ecological roles, functional redundancy can buffer ecosystems against species loss. Using data on the frequency of interactions between fish and fruit, we assessed whether co-occurring frugivores provide redundant seed dispersal services in three species-rich Neotropical wetlands. Our study revealed that frugivorous fishes have generalized diets; however, large-bodied fishes had greater seed dispersal breadth than small species, in some cases, providing seed dispersal services not achieved by smaller fish species. As overfishing disproportionately affects big fishes, the extirpation of these species could cause larger secondary extinctions of plant species than the loss of small specialist frugivores. To evaluate the consequences of frugivore specialization for network stability, we extracted data from 39 published seed dispersal networks of frugivorous birds, mammals and fish (our networks) across ecosystems. Our analysis of interaction frequencies revealed low frugivore specialization and lower nestedness than analyses based on binary data (presence–absence of interactions). In that case, ecosystems may be resilient to loss of any given frugivore. However, robustness to frugivore extinction declines with specialization, such that networks composed primarily of specialist frugivores are highly susceptible to the loss of generalists. In contrast with analyses of binary data, recently developed algorithms capable of modelling interaction strengths provide opportunities to enhance our understanding of complex ecological networks by accounting for heterogeneity of frugivore–fruit interactions. PMID:27581879

Perturbations to trophic interactions and the stability of complex food webs

PubMed Central

O'Gorman, Eoin J.; Emmerson, Mark C.

2009-01-01

The pattern of predator–prey interactions is thought to be a key determinant of ecosystem processes and stability. Complex ecological networks are characterized by distributions of interaction strengths that are highly skewed, with many weak and few strong interactors present. Theory suggests that this pattern promotes stability as weak interactors dampen the destabilizing potential of strong interactors. Here, we present an experimental test of this hypothesis and provide empirical evidence that the loss of weak interactors can destabilize communities in nature. We ranked 10 marine consumer species by the strength of their trophic interactions. We removed the strongest and weakest of these interactors from experimental food webs containing >100 species. Extinction of strong interactors produced a dramatic trophic cascade and reduced the temporal stability of key ecosystem process rates, community diversity and resistance to changes in community composition. Loss of weak interactors also proved damaging for our experimental ecosystems, leading to reductions in the temporal and spatial stability of ecosystem process rates, community diversity, and resistance. These results highlight the importance of conserving species to maintain the stabilizing pattern of trophic interactions in nature, even if they are perceived to have weak effects in the system. PMID:19666606

Microbial ecology of fermentative hydrogen producing bioprocesses: useful insights for driving the ecosystem function.

PubMed

Cabrol, Lea; Marone, Antonella; Tapia-Venegas, Estela; Steyer, Jean-Philippe; Ruiz-Filippi, Gonzalo; Trably, Eric

2017-03-01

One of the most important biotechnological challenges is to develop environment friendly technologies to produce new sources of energy. Microbial production of biohydrogen through dark fermentation, by conversion of residual biomass, is an attractive solution for short-term development of bioH2 producing processes. Efficient biohydrogen production relies on complex mixed communities working in tight interaction. Species composition and functional traits are of crucial importance to maintain the ecosystem service. The analysis of microbial community revealed a wide phylogenetic diversity that contributes in different-and still mostly unclear-ways to hydrogen production. Bridging this gap of knowledge between microbial ecology features and ecosystem functionality is essential to optimize the bioprocess and develop strategies toward a maximization of the efficiency and stability of substrate conversion. The aim of this review is to provide a comprehensive overview of the most up-to-date biodata available and discuss the main microbial community features of biohydrogen engineered ecosystems, with a special emphasis on the crucial role of interactions and the relationships between species composition and ecosystem service. The elucidation of intricate relationships between community structure and ecosystem function would make possible to drive ecosystems toward an improved functionality on the basis of microbial ecology principles. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Pollination systems involving floral mimicry of fruit: aspects of their ecology and evolution.

PubMed

Goodrich, Katherine R; Jürgens, Andreas

2018-01-01

Floral mimicry of nonfloral resources is found across many angiosperm families, with mimicry of varied models including carrion, dung, fungi, insects and fruit. These systems provide excellent models to investigate the role of visual and olfactory cues for the ecology and evolution of plant-animal interactions. Interestingly, floral mimicry of fruit is least documented in the literature, although ripe or rotting fruits play an important role as a food or brood site in many insect groups such as Diptera, Hymenoptera and Coleoptera, and frugivorous vertebrates such as bats and birds. In ecosystems where fruit represents a frequent, reliable resource (e.g. tropical forests), this form of floral mimicry could represent a common mimicry class with specialization possible along multiple axes such as fruit of different species, stages of ripeness and microbial colonization. In this review, we summarize current research on floral mimicry of fruit. We place this review in the context of floral mimicry of a broader spectrum of nonfloral resources, and we discuss conceptual frameworks of mimicry vs generalized food deception or pre-existing sensory bias. Finally, we briefly review the specificity and complexity of fruit-insect ecological interactions, and we summarize important considerations and questions for moving forward in this field. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Historical foundations and future directions in macrosystems ecology.

PubMed

Rose, Kevin C; Graves, Rose A; Hansen, Winslow D; Harvey, Brian J; Qiu, Jiangxiao; Wood, Stephen A; Ziter, Carly; Turner, Monica G

2017-02-01

Macrosystems ecology is an effort to understand ecological processes and interactions at the broadest spatial scales and has potential to help solve globally important social and ecological challenges. It is important to understand the intellectual legacies underpinning macrosystems ecology: How the subdiscipline fits within, builds upon, differs from and extends previous theories. We trace the rise of macrosystems ecology with respect to preceding theories and present a new hypothesis that integrates the multiple components of macrosystems theory. The spatio-temporal anthropogenic rescaling (STAR) hypothesis suggests that human activities are altering the scales of ecological processes, resulting in interactions at novel space-time scale combinations that are diverse and predictable. We articulate four predictions about how human actions are "expanding", "shrinking", "speeding up" and "slowing down" ecological processes and interactions, and thereby generating new scaling relationships for ecological patterns and processes. We provide examples of these rescaling processes and describe ecological consequences across terrestrial, freshwater and marine ecosystems. Rescaling depends in part on characteristics including connectivity, stability and heterogeneity. Our STAR hypothesis challenges traditional assumptions about how the spatial and temporal scales of processes and interactions operate in different types of ecosystems and provides a lens through which to understand macrosystem-scale environmental change. © 2016 John Wiley & Sons Ltd/CNRS.

Interactive exploration of coastal restoration modeling in virtual environments

NASA Astrophysics Data System (ADS)

Gerndt, Andreas; Miller, Robert; Su, Simon; Meselhe, Ehab; Cruz-Neira, Carolina

2009-02-01

Over the last decades, Louisiana has lost a substantial part of its coastal region to the Gulf of Mexico. The goal of the project depicted in this paper is to investigate the complex ecological and geophysical system not only to find solutions to reverse this development but also to protect the southern landscape of Louisiana for disastrous impacts of natural hazards like hurricanes. This paper sets a focus on the interactive data handling of the Chenier Plain which is only one scenario of the overall project. The challenge addressed is the interactive exploration of large-scale time-depending 2D simulation results and of terrain data with a high resolution that is available for this region. Besides data preparation, efficient visualization approaches optimized for the usage in virtual environments are presented. These are embedded in a complex framework for scientific visualization of time-dependent large-scale datasets. To provide a straightforward interface for rapid application development, a software layer called VRFlowVis has been developed. Several architectural aspects to encapsulate complex virtual reality aspects like multi-pipe vs. cluster-based rendering are discussed. Moreover, the distributed post-processing architecture is investigated to prove its efficiency for the geophysical domain. Runtime measurements conclude this paper.

Biogeography of diseases: a framework for analysis

NASA Astrophysics Data System (ADS)

Peterson, A. Townsend

2008-06-01

A growing body of literature offers a framework for understanding geographic and ecological distributions of species; a few applications of this framework have treated disease transmission systems and their geography. The general framework focuses on interactions among abiotic requirements, biotic constraints, and dispersal abilities of species as determinants of distributional areas. Disease transmission systems have key differences from other sorts of biological phenomena: Interactions among species are particularly important, interactions may be stable or unstable, abiotic conditions may be relatively less important in shaping disease distributions, and dispersal abilities may be quite variable. The ways in which these differences may influence disease transmission geography are complex; I illustrate their effects by means of worked examples regarding West Nile Virus, plague, filoviruses, and yellow fever.

Trophic disruption: a meta-analysis of how habitat fragmentation affects resource consumption in terrestrial arthropod systems.

PubMed

Martinson, Holly M; Fagan, William F

2014-09-01

Habitat fragmentation is a complex process that affects ecological systems in diverse ways, altering everything from population persistence to ecosystem function. Despite widespread recognition that habitat fragmentation can influence food web interactions, consensus on the factors underlying variation in the impacts of fragmentation across systems remains elusive. In this study, we conduct a systematic review and meta-analysis to quantify the effects of habitat fragmentation and spatial habitat structure on resource consumption in terrestrial arthropod food webs. Across 419 studies, we found a negative overall effect of fragmentation on resource consumption. Variation in effect size was extensive but predictable. Specifically, resource consumption was reduced on small, isolated habitat fragments, higher at patch edges, and neutral with respect to landscape-scale spatial variables. In general, resource consumption increased in fragmented settings for habitat generalist consumers but decreased for specialist consumers. Our study demonstrates widespread disruption of trophic interactions in fragmented habitats and describes variation among studies that is largely predictable based on the ecological traits of the interacting species. We highlight future prospects for understanding how changes in spatial habitat structure may influence trophic modules and food webs. © 2014 John Wiley & Sons Ltd/CNRS.

Understanding movement data and movement processes: current and emerging directions.

PubMed

Schick, Robert S; Loarie, Scott R; Colchero, Fernando; Best, Benjamin D; Boustany, Andre; Conde, Dalia A; Halpin, Patrick N; Joppa, Lucas N; McClellan, Catherine M; Clark, James S

2008-12-01

Animal movement has been the focus on much theoretical and empirical work in ecology over the last 25 years. By studying the causes and consequences of individual movement, ecologists have gained greater insight into the behavior of individuals and the spatial dynamics of populations at increasingly higher levels of organization. In particular, ecologists have focused on the interaction between individuals and their environment in an effort to understand future impacts from habitat loss and climate change. Tools to examine this interaction have included: fractal analysis, first passage time, Lévy flights, multi-behavioral analysis, hidden markov models, and state-space models. Concurrent with the development of movement models has been an increase in the sophistication and availability of hierarchical bayesian models. In this review we bring these two threads together by using hierarchical structures as a framework for reviewing individual models. We synthesize emerging themes in movement ecology, and propose a new hierarchical model for animal movement that builds on these emerging themes. This model moves away from traditional random walks, and instead focuses inference on how moving animals with complex behavior interact with their landscape and make choices about its suitability.

A promising future for integrative biodiversity research: an increased role of scale-dependency and functional biology.

PubMed

Price, S A; Schmitz, L

2016-04-05

Studies into the complex interaction between an organism and changes to its biotic and abiotic environment are fundamental to understanding what regulates biodiversity. These investigations occur at many phylogenetic, temporal and spatial scales and within a variety of biological and geological disciplines but often in relative isolation. This issue focuses on what can be achieved when ecological mechanisms are integrated into analyses of deep-time biodiversity patterns through the union of fossil and extant data and methods. We expand upon this perspective to argue that, given its direct relevance to the current biodiversity crisis, greater integration is needed across biodiversity research. We focus on the need to understand scaling effects, how lower-level ecological and evolutionary processes scale up and vice versa, and the importance of incorporating functional biology. Placing function at the core of biodiversity research is fundamental, as it establishes how an organism interacts with its abiotic and biotic environment and it is functional diversity that ultimately determines important ecosystem processes. To achieve full integration, concerted and ongoing efforts are needed to build a united and interactive community of biodiversity researchers, with education and interdisciplinary training at its heart. © 2016 The Author(s).

Helminth infection during pregnancy: insights from evolutionary ecology

PubMed Central

Blackwell, Aaron D

2016-01-01

Helminths are parasitic nematodes and trematodes, grouped together because of morphological similarities and commonalities in the effects infections have on hosts. These include complications such as anemia and biasing of immune responses, which can alter susceptibility for other diseases. For pregnant women, these complications might have implications for pregnancy outcomes or neonatal health. Here, I review studies of helminth infections during pregnancy, and ask the following questions: Do helminths affect maternal health or pregnancy outcomes? Are there consequences of maternal infection for infants? What are the effects of antihelminth treatment during pregnancy? The evidence suggests that the answers to these questions depend on the particular helminth species in question, maternal nutritional status, and the presence or absence of comorbid infection with other species, such as malaria. Moreover, there may also be unexpected consequences of treatment, as maternal infections can affect the priming of infant immune systems, with potential effects on infants later in life. These complex interactions suggest that a consideration of the evolutionary history of human–helminth interactions, as well as the ecological context of infections, can help to clarify an understanding of these host–parasite interactions and provide direction for future investigations. PMID:27956844

Cultural evolutionary theory: How culture evolves and why it matters

PubMed Central

Creanza, Nicole; Kolodny, Oren; Feldman, Marcus W.

2017-01-01

Human cultural traits—behaviors, ideas, and technologies that can be learned from other individuals—can exhibit complex patterns of transmission and evolution, and researchers have developed theoretical models, both verbal and mathematical, to facilitate our understanding of these patterns. Many of the first quantitative models of cultural evolution were modified from existing concepts in theoretical population genetics because cultural evolution has many parallels with, as well as clear differences from, genetic evolution. Furthermore, cultural and genetic evolution can interact with one another and influence both transmission and selection. This interaction requires theoretical treatments of gene–culture coevolution and dual inheritance, in addition to purely cultural evolution. In addition, cultural evolutionary theory is a natural component of studies in demography, human ecology, and many other disciplines. Here, we review the core concepts in cultural evolutionary theory as they pertain to the extension of biology through culture, focusing on cultural evolutionary applications in population genetics, ecology, and demography. For each of these disciplines, we review the theoretical literature and highlight relevant empirical studies. We also discuss the societal implications of the study of cultural evolution and of the interactions of humans with one another and with their environment. PMID:28739941

A promising future for integrative biodiversity research: an increased role of scale-dependency and functional biology

PubMed Central

Schmitz, L.

2016-01-01

Studies into the complex interaction between an organism and changes to its biotic and abiotic environment are fundamental to understanding what regulates biodiversity. These investigations occur at many phylogenetic, temporal and spatial scales and within a variety of biological and geological disciplines but often in relative isolation. This issue focuses on what can be achieved when ecological mechanisms are integrated into analyses of deep-time biodiversity patterns through the union of fossil and extant data and methods. We expand upon this perspective to argue that, given its direct relevance to the current biodiversity crisis, greater integration is needed across biodiversity research. We focus on the need to understand scaling effects, how lower-level ecological and evolutionary processes scale up and vice versa, and the importance of incorporating functional biology. Placing function at the core of biodiversity research is fundamental, as it establishes how an organism interacts with its abiotic and biotic environment and it is functional diversity that ultimately determines important ecosystem processes. To achieve full integration, concerted and ongoing efforts are needed to build a united and interactive community of biodiversity researchers, with education and interdisciplinary training at its heart. PMID:26977068

Cultural evolutionary theory: How culture evolves and why it matters.

PubMed

Creanza, Nicole; Kolodny, Oren; Feldman, Marcus W

2017-07-24

Human cultural traits-behaviors, ideas, and technologies that can be learned from other individuals-can exhibit complex patterns of transmission and evolution, and researchers have developed theoretical models, both verbal and mathematical, to facilitate our understanding of these patterns. Many of the first quantitative models of cultural evolution were modified from existing concepts in theoretical population genetics because cultural evolution has many parallels with, as well as clear differences from, genetic evolution. Furthermore, cultural and genetic evolution can interact with one another and influence both transmission and selection. This interaction requires theoretical treatments of gene-culture coevolution and dual inheritance, in addition to purely cultural evolution. In addition, cultural evolutionary theory is a natural component of studies in demography, human ecology, and many other disciplines. Here, we review the core concepts in cultural evolutionary theory as they pertain to the extension of biology through culture, focusing on cultural evolutionary applications in population genetics, ecology, and demography. For each of these disciplines, we review the theoretical literature and highlight relevant empirical studies. We also discuss the societal implications of the study of cultural evolution and of the interactions of humans with one another and with their environment.

Towards a comprehensive understanding of emerging dynamics and function of pancreatic islets: A complex network approach. Comment on "Network science of biological systems at different scales: A review" by Gosak et al.

NASA Astrophysics Data System (ADS)

Loppini, Alessandro

2018-03-01

Complex network theory represents a comprehensive mathematical framework to investigate biological systems, ranging from sub-cellular and cellular scales up to large-scale networks describing species interactions and ecological systems. In their exhaustive and comprehensive work [1], Gosak et al. discuss several scenarios in which the network approach was able to uncover general properties and underlying mechanisms of cells organization and regulation, tissue functions and cell/tissue failure in pathology, by the study of chemical reaction networks, structural networks and functional connectivities.

A conceptual socio-hydrological model of the co-evolution of humans and water: case study of the Tarim River basin, western China

NASA Astrophysics Data System (ADS)

Liu, D.; Tian, F.; Lin, M.; Sivapalan, M.

2015-02-01

The complex interactions and feedbacks between humans and water are critically important issues but remain poorly understood in the newly proposed discipline of socio-hydrology (Sivapalan et al., 2012). An exploratory model with the appropriate level of simplification can be valuable for improving our understanding of the co-evolution and self-organization of socio-hydrological systems driven by interactions and feedbacks operating at different scales. In this study, a simplified conceptual socio-hydrological model based on logistic growth curves is developed for the Tarim River basin in western China and is used to illustrate the explanatory power of such a co-evolutionary model. The study area is the main stream of the Tarim River, which is divided into two modeling units. The socio-hydrological system is composed of four sub-systems, i.e., the hydrological, ecological, economic, and social sub-systems. In each modeling unit, the hydrological equation focusing on water balance is coupled to the other three evolutionary equations to represent the dynamics of the social sub-system (denoted by population), the economic sub-system (denoted by irrigated crop area ratio), and the ecological sub-system (denoted by natural vegetation cover), each of which is expressed in terms of a logistic growth curve. Four feedback loops are identified to represent the complex interactions among different sub-systems and different spatial units, of which two are inner loops occurring within each separate unit and the other two are outer loops linking the two modeling units. The feedback mechanisms are incorporated into the constitutive relations for model parameters, i.e., the colonization and mortality rates in the logistic growth curves that are jointly determined by the state variables of all sub-systems. The co-evolution of the Tarim socio-hydrological system is then analyzed with this conceptual model to gain insights into the overall system dynamics and its sensitivity to the external drivers and internal system variables. The results show a costly pendulum swing between a balanced distribution of socio-economic and natural ecologic resources among the upper and lower reaches and a highly skewed distribution towards the upper reach. This evolution is principally driven by the attitudinal changes occurring within water resources management policies that reflect the evolving community awareness of society to concerns regarding the ecology and environment.

Cross-Study Comparison Reveals Common Genomic, Network, and Functional Signatures of Desiccation Resistance in Drosophila melanogaster

PubMed Central

Telonis-Scott, Marina; Sgrò, Carla M.; Hoffmann, Ary A.; Griffin, Philippa C.

2016-01-01

Repeated attempts to map the genomic basis of complex traits often yield different outcomes because of the influence of genetic background, gene-by-environment interactions, and/or statistical limitations. However, where repeatability is low at the level of individual genes, overlap often occurs in gene ontology categories, genetic pathways, and interaction networks. Here we report on the genomic overlap for natural desiccation resistance from a Pool-genome-wide association study experiment and a selection experiment in flies collected from the same region in southeastern Australia in different years. We identified over 600 single nucleotide polymorphisms associated with desiccation resistance in flies derived from almost 1,000 wild-caught genotypes, a similar number of loci to that observed in our previous genomic study of selected lines, demonstrating the genetic complexity of this ecologically important trait. By harnessing the power of cross-study comparison, we narrowed the candidates from almost 400 genes in each study to a core set of 45 genes, enriched for stimulus, stress, and defense responses. In addition to gene-level overlap, there was higher order congruence at the network and functional levels, suggesting genetic redundancy in key stress sensing, stress response, immunity, signaling, and gene expression pathways. We also identified variants linked to different molecular aspects of desiccation physiology previously verified from functional experiments. Our approach provides insight into the genomic basis of a complex and ecologically important trait and predicts candidate genetic pathways to explore in multiple genetic backgrounds and related species within a functional framework. PMID:26733490

Before the Endless Forms: Embodied Model of Transition from Single Cells to Aggregates to Ecosystem Engineering

PubMed Central

Solé, Ricard V.; Valverde, Sergi

2013-01-01

The emergence of complex multicellular systems and their associated developmental programs is one of the major problems of evolutionary biology. The advantages of cooperation over individuality seem well known but it is not clear yet how such increase of complexity emerged from unicellular life forms. Current multicellular systems display a complex cell-cell communication machinery, often tied to large-scale controls of body size or tissue homeostasis. Some unicellular life forms are simpler and involve groups of cells cooperating in a tissue-like fashion, as it occurs with biofilms. However, before true gene regulatory interactions were widespread and allowed for controlled changes in cell phenotypes, simple cellular colonies displaying adhesion and interacting with their environments were in place. In this context, models often ignore the physical embedding of evolving cells, thus leaving aside a key component. The potential for evolving pre-developmental patterns is a relevant issue: how far a colony of evolving cells can go? Here we study these pre-conditions for morphogenesis by using CHIMERA, a physically embodied computational model of evolving virtual organisms in a pre-Mendelian world. Starting from a population of identical, independent cells moving in a fluid, the system undergoes a series of changes, from spatial segregation, increased adhesion and the development of generalism. Eventually, a major transition occurs where a change in the flow of nutrients is triggered by a sub-population. This ecosystem engineering phenomenon leads to a subsequent separation of the ecological network into two well defined compartments. The relevance of these results for evodevo and its potential ecological triggers is discussed. PMID:23596506

Ecological implications of extreme events: footprints of the 2010 earthquake along the Chilean coast.

PubMed

Jaramillo, Eduardo; Dugan, Jenifer E; Hubbard, David M; Melnick, Daniel; Manzano, Mario; Duarte, Cristian; Campos, Cesar; Sanchez, Roland

2012-01-01

Deciphering ecological effects of major catastrophic events such as earthquakes, tsunamis, volcanic eruptions, storms and fires, requires rapid interdisciplinary efforts often hampered by a lack of pre-event data. Using results of intertidal surveys conducted shortly before and immediately after Chile's 2010 M(w) 8.8 earthquake along the entire rupture zone (ca. 34-38°S), we provide the first quantification of earthquake and tsunami effects on sandy beach ecosystems. Our study incorporated anthropogenic coastal development as a key design factor. Ecological responses of beach ecosystems were strongly affected by the magnitude of land-level change. Subsidence along the northern rupture segment combined with tsunami-associated disturbance and drowned beaches. In contrast, along the co-seismically uplifted southern rupture, beaches widened and flattened increasing habitat availability. Post-event changes in abundance and distribution of mobile intertidal invertebrates were not uniform, varying with land-level change, tsunami height and coastal development. On beaches where subsidence occurred, intertidal zones and their associated species disappeared. On some beaches, uplift of rocky sub-tidal substrate eliminated low intertidal sand beach habitat for ecologically important species. On others, unexpected interactions of uplift with man-made coastal armouring included restoration of upper and mid-intertidal habitat seaward of armouring followed by rapid colonization of mobile crustaceans typical of these zones formerly excluded by constraints imposed by the armouring structures. Responses of coastal ecosystems to major earthquakes appear to vary strongly with land-level change, the mobility of the biota and shore type. Our results show that interactions of extreme events with human-altered shorelines can produce surprising ecological outcomes, and suggest these complex responses to landscape alteration can leave lasting footprints in coastal ecosystems.

No complexity–stability relationship in empirical ecosystems

PubMed Central

Jacquet, Claire; Moritz, Charlotte; Morissette, Lyne; Legagneux, Pierre; Massol, François; Archambault, Philippe; Gravel, Dominique

2016-01-01

Understanding the mechanisms responsible for stability and persistence of ecosystems is one of the greatest challenges in ecology. Robert May showed that, contrary to intuition, complex randomly built ecosystems are less likely to be stable than simpler ones. Few attempts have been tried to test May's prediction empirically, and we still ignore what is the actual complexity–stability relationship in natural ecosystems. Here we perform a stability analysis of 116 quantitative food webs sampled worldwide. We find that classic descriptors of complexity (species richness, connectance and interaction strength) are not associated with stability in empirical food webs. Further analysis reveals that a correlation between the effects of predators on prey and those of prey on predators, combined with a high frequency of weak interactions, stabilize food web dynamics relative to the random expectation. We conclude that empirical food webs have several non-random properties contributing to the absence of a complexity–stability relationship. PMID:27553393

Cross-scale morphology

USGS Publications Warehouse

Allen, Craig R.; Holling, Crawford S.; Garmestani, Ahjond S.; El-Shaarawi, Abdel H.; Piegorsch, Walter W.

2013-01-01

The scaling of physical, biological, ecological and social phenomena is a major focus of efforts to develop simple representations of complex systems. Much of the attention has been on discovering universal scaling laws that emerge from simple physical and geometric processes. However, there are regular patterns of departures both from those scaling laws and from continuous distributions of attributes of systems. Those departures often demonstrate the development of self-organized interactions between living systems and physical processes over narrower ranges of scale.

Cross-scale interactions: Quantifying multi-scaled cause–effect relationships in macrosystems

USGS Publications Warehouse

Soranno, Patricia A.; Cheruvelil, Kendra S.; Bissell, Edward G.; Bremigan, Mary T.; Downing, John A.; Fergus, Carol E.; Filstrup, Christopher T.; Henry, Emily N.; Lottig, Noah R.; Stanley, Emily H.; Stow, Craig A.; Tan, Pang-Ning; Wagner, Tyler; Webster, Katherine E.

2014-01-01

Ecologists are increasingly discovering that ecological processes are made up of components that are multi-scaled in space and time. Some of the most complex of these processes are cross-scale interactions (CSIs), which occur when components interact across scales. When undetected, such interactions may cause errors in extrapolation from one region to another. CSIs, particularly those that include a regional scaled component, have not been systematically investigated or even reported because of the challenges of acquiring data at sufficiently broad spatial extents. We present an approach for quantifying CSIs and apply it to a case study investigating one such interaction, between local and regional scaled land-use drivers of lake phosphorus. Ultimately, our approach for investigating CSIs can serve as a basis for efforts to understand a wide variety of multi-scaled problems such as climate change, land-use/land-cover change, and invasive species.

Efficacy of Two Different Instructional Methods Involving Complex Ecological Content

ERIC Educational Resources Information Center

Randler, Christoph; Bogner, Franz X.

2009-01-01

Teaching and learning approaches in ecology very often follow linear conceptions of ecosystems. Empirical studies with an ecological focus consistent with existing syllabi and focusing on cognitive achievement are scarce. Consequently, we concentrated on a classroom unit that offers learning materials and highlights the existing complexity rather…

The assembly and disassembly of ecological networks.

PubMed

Bascompte, Jordi; Stouffer, Daniel B

2009-06-27

Global change has created a severe biodiversity crisis. Species are driven extinct at an increasing rate, and this has the potential to cause further coextinction cascades. The rate and shape of these coextinction cascades depend very much on the structure of the networks of interactions across species. Understanding network structure and how it relates to network disassembly, therefore, is a priority for system-level conservation biology. This process of network collapse may indeed be related to the process of network build-up, although very little is known about both processes and even less about their relationship. Here we review recent work that provides some preliminary answers to these questions. First, we focus on network assembly by emphasizing temporal processes at the species level, as well as the structural building blocks of complex ecological networks. Second, we focus on network disassembly as a consequence of species extinctions or habitat loss. We conclude by emphasizing some general rules of thumb that can help in building a comprehensive framework to understand the responses of ecological networks to global change.

Survivial Strategies in Bacterial Range Expansions

NASA Astrophysics Data System (ADS)

Frey, Erwin

2014-03-01

Bacterial communities represent complex and dynamic ecological systems. Different environmental conditions as well as bacterial interactions determine the establishment and sustainability of bacterial diversity. In this talk we discuss the competition of three Escherichia coli strains during range expansions on agar plates. In this bacterial model system, a colicin E2 producing strain C competes with a colicin resistant strain R and with a colicin sensitive strain S for new territory. Genetic engineering allows us to tune the growth rates of the strains and to study distinct ecological scenarios. These scenarios may lead to either single-strain dominance, pairwise coexistence, or to the coexistence of all three strains. In order to elucidate the survival mechanisms of the individual strains, we also developed a stochastic agent-based model to capture the ecological scenarios in silico. In a combined theoretical and experimental approach we are able to show that the level of biodiversity depends crucially on the composition of the inoculum, on the relative growth rates of the three strains, and on the effective reach of colicin toxicity.

The influence of the interactions between anthropogenic activities and multiple ecological factors on land surface temperatures of urban forests

NASA Astrophysics Data System (ADS)

Ren, Y.

2017-12-01

Context Land surface temperatures (LSTs) spatio-temporal distribution pattern of urban forests are influenced by many ecological factors; the identification of interaction between these factors can improve simulations and predictions of spatial patterns of urban cold islands. This quantitative research requires an integrated method that combines multiple sources data with spatial statistical analysis. Objectives The purpose of this study was to clarify urban forest LST influence interaction between anthropogenic activities and multiple ecological factors using cluster analysis of hot and cold spots and Geogdetector model. We introduced the hypothesis that anthropogenic activity interacts with certain ecological factors, and their combination influences urban forests LST. We also assumed that spatio-temporal distributions of urban forest LST should be similar to those of ecological factors and can be represented quantitatively. Methods We used Jinjiang as a representative city in China as a case study. Population density was employed to represent anthropogenic activity. We built up a multi-source data (forest inventory, digital elevation models (DEM), population, and remote sensing imagery) on a unified urban scale to support urban forest LST influence interaction research. Through a combination of spatial statistical analysis results, multi-source spatial data, and Geogdetector model, the interaction mechanisms of urban forest LST were revealed. Results Although different ecological factors have different influences on forest LST, in two periods with different hot spots and cold spots, the patch area and dominant tree species were the main factors contributing to LST clustering in urban forests. The interaction between anthropogenic activity and multiple ecological factors increased LST in urban forest stands, linearly and nonlinearly. Strong interactions between elevation and dominant species were generally observed and were prevalent in either hot or cold spots areas in different years. Conclusions In conclusion, a combination of spatial statistics and GeogDetector models should be effective for quantitatively evaluating interactive relationships among ecological factors, anthropogenic activity and LST.

The influence of drought on flow‐ecology relationships in Ozark Highland streams

USGS Publications Warehouse

Lynch, Dustin T.; Leasure, D. R.; Magoulick, Daniel D.

2018-01-01

Drought and summer drying can have strong effects on abiotic and biotic components of stream ecosystems. Environmental flow‐ecology relationships may be affected by drought and drying, adding further uncertainty to the already complex interaction of flow with other environmental variables, including geomorphology and water quality.Environment–ecology relationships in stream communities in Ozark Highland streams, USA, were examined over two years with contrasting environmental conditions, a drought year (2012) and a flood year (2013). We analysed fish, crayfish and benthic macroinvertebrate assemblages using two different approaches: (1) a multiple regression analysis incorporating predictor variables related to habitat, water quality, geomorphology and hydrology and (2) a canonical ordination procedure using only hydrologic variables in which forward selection was used to select predictors that were most related to our response variables.Reach‐scale habitat quality and geomorphology were found to be the most important influences on community structure, but hydrology was also important, particularly during the flood year. We also found substantial between‐year variation in environment–ecology relationships. Some ecological responses differed significantly between drought and flood years, while others remained consistent. We found that magnitude was the most important flow component overall, but that there was a shift in relative importance from low flow metrics during the drought year to average flow metrics during the flood year, and the specific metrics of importance varied markedly between assemblages and years.Findings suggest that understanding temporal variation in flow‐ecology relationships may be crucial for resource planning. While some relationships show temporal variation, others are consistent between years. Additionally, different kinds of hydrologic variables can differ greatly in terms of which assemblages they affect and how they affect them. Managers can address this complexity by focusing on relationships that are temporally stable and flow metrics that are consistently important across groups, such as flood frequency and flow variability.

Genetic signatures of ecological diversity along an urbanization gradient.

PubMed

Kelly, Ryan P; O'Donnell, James L; Lowell, Natalie C; Shelton, Andrew O; Samhouri, Jameal F; Hennessey, Shannon M; Feist, Blake E; Williams, Gregory D

2016-01-01

Despite decades of work in environmental science and ecology, estimating human influences on ecosystems remains challenging. This is partly due to complex chains of causation among ecosystem elements, exacerbated by the difficulty of collecting biological data at sufficient spatial, temporal, and taxonomic scales. Here, we demonstrate the utility of environmental DNA (eDNA) for quantifying associations between human land use and changes in an adjacent ecosystem. We analyze metazoan eDNA sequences from water sampled in nearshore marine eelgrass communities and assess the relationship between these ecological communities and the degree of urbanization in the surrounding watershed. Counter to conventional wisdom, we find strongly increasing richness and decreasing beta diversity with greater urbanization, and similar trends in the diversity of life histories with urbanization. We also find evidence that urbanization influences nearshore communities at local (hundreds of meters) rather than regional (tens of km) scales. Given that different survey methods sample different components of an ecosystem, we then discuss the advantages of eDNA-which we use here to detect hundreds of taxa simultaneously-as a complement to traditional ecological sampling, particularly in the context of broad ecological assessments where exhaustive manual sampling is impractical. Genetic data are a powerful means of uncovering human-ecosystem interactions that might otherwise remain hidden; nevertheless, no sampling method reveals the whole of a biological community.

Assessment and management of ecological integrity: Chapter 12

USGS Publications Warehouse

Kwak, Thomas J.; Freeman, Mary C.

2010-01-01

Assessing and understanding the impacts of human activities on aquatic ecosystems has long been a focus of ecologists, water resources managers, and fisheries scientists. While traditional fisheries management focused on single-species approaches to enhance fish stocks, there is a growing emphasis on management approaches at community and ecosystem levels. Of course, as fisheries managers shift their attention from narrow (e.g., populations) to broad organizational scales (e.g., communities or ecosystems), ecological processes and management objectives become more complex. At the community level, fisheries managers may strive for a fish assemblage that is complex, persistent, and resilient to disturbance. Aquatic ecosystem level objectives may focus on management for habitat quality and ecological processes, such as nutrient dynamics, productivity, or trophic interactions, but a long-term goal of ecosystem management may be to maintain ecological integrity. However, human users and social, economic, and political demands of fisheries management often result in a reduction of ecological integrity in managed systems, and this conflict presents a principal challenge for the modern fisheries manager. The concepts of biotic integrity and ecological integrity are being applied in fisheries science, natural resource management, and environmental legislation, but explicit definitions of these terms are elusive. Biotic integrity of an ecosystem may be defined as the capability of supporting and maintaining an integrated, adaptive community of organisms having a species composition, diversity, and functional organization comparable to that of a natural habitat of the region (Karr and Dudley 1981). Following that, ecological integrity is the summation of chemical, physical, and biological integrity. Thus, the concept of ecological integrity extends beyond fish and represents a holistic approach for ecosystem management that is especially applicable to aquatic systems. The more general term, ecological condition, refers to the state of the physical, chemical, and biological characteristics of the environment and the processes and interactions that connect them. While the concept of ecological integrity may appear unambiguous, its assessment and practice are much less clear. Ecological integrity made its debut in the USA with the Clean Water Act (CWA) of 1972 (Federal Water Pollution Control Act, as amended through Public Law 107–303, November 27, 2002), which states only one objective, “to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.” This legislation compelled resource managers to focus on chemical pollution from point effluent sources, such as industrial and municipal outflows, as well as give attention to diffuse, chronic, and watershed effects on ecological integrity. Further, the CWA allowed pursuit of restoration programs in degraded water bodies and catalyzed the science and practice of restoration ecology. The term ecosystem health is often raised in discussions of ecological integrity. Perhaps it is natural to anthropomorphize our concern for personal health to ecosystems, so it becomes a useful metaphor for understanding the concept of ecological integrity. However, whether or not an ecosystem should be considered an entity, such as a superorganism, is a debate without end that began with early ecologists and continues today (Clements 1916; Suter 1993; Simon 1999a). Regardless, the ecosystem is indeed a natural unit with a level of organization and properties beyond the collection of those species that occupy it and presents the most appropriate spatial and organizational scale in which to assess and study ecological integrity. Streams and rivers serve as integrators of chemical, physical, and biological conditions across the landscape, and while the theory and practice associated with ecological integrity of aquatic systems is easily applied to flowing waters and is emphasized in this chapter, they are broadly applicable among all aquatic systems.

Size-Energy Relationships in Ecological Communities

PubMed Central

Sewall, Brent J.; Freestone, Amy L.; Hawes, Joseph E.; Andriamanarina, Ernest

2013-01-01

Hypotheses that relate body size to energy use are of particular interest in community ecology and macroecology because of their potential to facilitate quantitative predictions about species interactions and to clarify complex ecological patterns. One prominent size-energy hypothesis, the energetic equivalence hypothesis, proposes that energy use from shared, limiting resources by populations or size classes of foragers will be independent of body size. Alternative hypotheses propose that energy use will increase with body size, decrease with body size, or peak at an intermediate body size. Despite extensive study, however, size-energy hypotheses remain controversial, due to a lack of directly-measured data on energy use, a tendency to confound distinct scaling relationships, and insufficient attention to the ecological contexts in which predicted relationships are likely to occur. Our goal, therefore, was to directly evaluate size-energy hypotheses while clarifying how results would differ with alternate methods and assumptions. We comprehensively tested size-energy hypotheses in a vertebrate frugivore guild in a tropical forest in Madagascar. Our test of size-energy hypotheses, which is the first to examine energy intake directly, was consistent with the energetic equivalence hypothesis. This finding corresponds with predictions of metabolic theory and models of energy distribution in ecological communities, which imply that body size does not confer an advantage in competition for energy among populations or size classes of foragers. This result was robust to different assumptions about energy regulation. Our results from direct energy measurement, however, contrasted with those obtained with conventional methods of indirect inference from size-density relationships, suggesting that size-density relationships do not provide an appropriate proxy for size-energy relationships as has commonly been assumed. Our research also provides insights into mechanisms underlying local size-energy relationships and has important implications for predicting species interactions and for understanding the structure and dynamics of ecological communities. PMID:23950873

Multiple micro-predators controlling bacterial communities in the environment.

PubMed

Johnke, Julia; Cohen, Yossi; de Leeuw, Marina; Kushmaro, Ariel; Jurkevitch, Edouard; Chatzinotas, Antonis

2014-06-01

Predator-prey interactions are a main issue in ecological theory, including multispecies predator-prey relationships and intraguild predation. This knowledge is mainly based on the study of plants and animals, while its relevance for microorganisms is not well understood. The three key groups of micro-predators include protists, predatory bacteria and bacteriophages. They greatly differ in size, in prey specificity, in hunting strategies and in the resulting population dynamics. Yet, their potential to jointly control bacterial populations and reducing biomass in complex environments such as wastewater treatment plants is vast. Here, we present relevant ecological concepts and recent findings on micropredators, and propose that an integrative approach to predation at the microscale should be developed enabling the exploitation of this potential. Copyright © 2014 Elsevier Ltd. All rights reserved.

Experiments in mixed reality

NASA Astrophysics Data System (ADS)

Krum, David M.; Sadek, Ramy; Kohli, Luv; Olson, Logan; Bolas, Mark

2010-01-01

As part of the Institute for Creative Technologies and the School of Cinematic Arts at the University of Southern California, the Mixed Reality lab develops technologies and techniques for presenting realistic immersive training experiences. Such experiences typically place users within a complex ecology of social actors, physical objects, and collections of intents, motivations, relationships, and other psychological constructs. Currently, it remains infeasible to completely synthesize the interactivity and sensory signatures of such ecologies. For this reason, the lab advocates mixed reality methods for training and conducts experiments exploring such methods. Currently, the lab focuses on understanding and exploiting the elasticity of human perception with respect to representational differences between real and virtual environments. This paper presents an overview of three projects: techniques for redirected walking, displays for the representation of virtual humans, and audio processing to increase stress.

Communicative interactions involving plants: information, evolution, and ecology.

PubMed

Mescher, Mark C; Pearse, Ian S

2016-08-01

The role of information obtained via sensory cues and signals in mediating the interactions of organisms with their biotic and abiotic environments has been a major focus of work on sensory and behavioral ecology. Information-mediated interactions also have important implications for broader ecological patterns emerging at the community and ecosystem levels that are only now beginning to be explored. Given the extent to which plants dominate the sensory landscapes of terrestrial ecosystems, information-mediated interactions involving plants should be a major focus of efforts to elucidate these broader patterns. Here we explore how such efforts might be enhanced by a clear understanding of information itself-a central and potentially unifying concept in biology that has nevertheless been the subject of considerable confusion-and of its relationship to adaptive evolution and ecology. We suggest that information-mediated interactions should be a key focus of efforts to more fully integrate evolutionary biology and ecology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Parasites, ecosystems and sustainability: an ecological and complex systems perspective.

PubMed

Horwitz, Pierre; Wilcox, Bruce A

2005-06-01

Host-parasite relationships can be conceptualised either narrowly, where the parasite is metabolically dependent on the host, or more broadly, as suggested by an ecological-evolutionary and complex systems perspective. In this view Host-parasite relationships are part of a larger set of ecological and co-evolutionary interdependencies and a complex adaptive system. These interdependencies affect not just the hosts, vectors, parasites, the immediate agents, but also those indirectly or consequentially affected by the relationship. Host-parasite relationships also can be viewed as systems embedded within larger systems represented by ecological communities and ecosystems. So defined, it can be argued that Host-parasite relationships may often benefit their hosts and contribute significantly to the structuring of ecological communities. The broader, complex adaptive system view also contributes to understanding the phenomenon of disease emergence, the ecological and evolutionary mechanisms involved, and the role of parasitology in research and management of ecosystems in light of the apparently growing problem of emerging infectious diseases in wildlife and humans. An expanded set of principles for integrated parasite management is suggested by this perspective.

Rapid evolution of hosts begets species diversity at the cost of intraspecific diversity

PubMed Central

Frickel, Jens; Theodosiou, Loukas

2017-01-01

Ecosystems are complex food webs in which multiple species interact and ecological and evolutionary processes continuously shape populations and communities. Previous studies on eco-evolutionary dynamics have shown that the presence of intraspecific diversity affects community structure and function, and that eco-evolutionary feedback dynamics can be an important driver for its maintenance. Within communities, feedbacks are, however, often indirect, and they can feed back over many generations. Here, we studied eco-evolutionary feedbacks in evolving communities over many generations and compared two-species systems (virus–host and prey–predator) with a more complex three-species system (virus–host–predator). Both indirect density- and trait-mediated effects drove the dynamics in the complex system, where host–virus coevolution facilitated coexistence of predator and virus, and where coexistence, in return, lowered intraspecific diversity of the host population. Furthermore, ecological and evolutionary dynamics were significantly altered in the three-species system compared with the two-species systems. We found that the predator slowed host–virus coevolution in the complex system and that the virus’ effect on the overall population dynamics was negligible when the three species coexisted. Overall, we show that a detailed understanding of the mechanism driving eco-evolutionary feedback dynamics is necessary for explaining trait and species diversity in communities, even in communities with only three species. PMID:28973943

Board-invited review: Rumen microbiology: leading the way in microbial ecology.

PubMed

Krause, D O; Nagaraja, T G; Wright, A D G; Callaway, T R

2013-01-01

Robert Hungate, considered the father of rumen microbiology, was the first to initiate a systematic exploration of the microbial ecosystem of the rumen, but he was not alone. The techniques he developed to isolate and identify cellulose-digesting bacteria from the rumen have had a major impact not only in delineating the complex ecosystem of the rumen but also in clinical microbiology and in the exploration of a number of other anaerobic ecosystems, including the human hindgut. Rumen microbiology has pioneered our understanding of much of microbial ecology and has broadened our knowledge of ecology in general, as well as improved the ability to feed ruminants more efficiently. The discovery of anaerobic fungi as a component of the ruminal flora disproved the central dogma in microbiology that all fungi are aerobic organisms. Further novel interactions between bacterial species such as nutrient cross feeding and interspecies H2 transfer were first described in ruminal microorganisms. The complexity and diversity present in the rumen make it an ideal testing ground for microbial theories (e.g., the effects of nutrient limitation and excess) and techniques (such as 16S rRNA), which have rewarded the investigators that have used this easily accessed ecosystem to understand larger truths. Our understanding of characteristics of the ruminal microbial population has opened new avenues of microbial ecology, such as the existence of hyperammonia-producing bacteria and how they can be used to improve N efficiency in ruminants. In this review, we examine some of the contributions to science that were first made in the rumen, which have not been recognized in a broader sense.

Competition induces allelopathy but suppresses growth and anti-herbivore defence in a chemically rich seaweed

PubMed Central

Rasher, Douglas B.; Hay, Mark E.

2014-01-01

Many seaweeds and terrestrial plants induce chemical defences in response to herbivory, but whether they induce chemical defences against competitors (allelopathy) remains poorly understood. We evaluated whether two tropical seaweeds induce allelopathy in response to competition with a reef-building coral. We also assessed the effects of competition on seaweed growth and seaweed chemical defence against herbivores. Following 8 days of competition with the coral Porites cylindrica, the chemically rich seaweed Galaxaura filamentosa induced increased allelochemicals and became nearly twice as damaging to the coral. However, it also experienced significantly reduced growth and increased palatability to herbivores (because of reduced chemical defences). Under the same conditions, the seaweed Sargassum polycystum did not induce allelopathy and did not experience a change in growth or palatability. This is the first demonstration of induced allelopathy in a seaweed, or of competitors reducing seaweed chemical defences against herbivores. Our results suggest that the chemical ecology of coral–seaweed–herbivore interactions can be complex and nuanced, highlighting the need to incorporate greater ecological complexity into the study of chemical defence. PMID:24403332

Balancing Control and Complexity in Field Studies of Neonicotinoids and Honey Bee Health

PubMed Central

Suryanarayanan, Sainath

2013-01-01

Amidst ongoing declines in honey bee health, the contributory role of the newer systemic insecticides continues to be intensely debated. Scores of toxicological field experiments, which bee scientists and regulators in the United States have looked to for definitive causal evidence, indicate a lack of support. This paper analyzes the methodological norms that shape the design and interpretation of field toxicological studies. I argue that contemporary field studies of honey bees and pesticides are underpinned by a “control-oriented” approach, which precludes a serious investigation of the indirect and multifactorial ways in which pesticides could drive declines in honey bee health. I trace the historical rise to prominence of this approach in honey bee toxicology to the development of entomology as a science of insecticide development in the United States. Drawing on “complexity-oriented” knowledge practices in ecology, epidemiology, beekeeping and sociology, I suggest an alternative socio-ecological systems approach, which would entail in situ studies that are less concerned with isolating individual factors and more attentive to the interactive and place-based mix of factors affecting honey bee health. PMID:26466800

Random forests for classification in ecology

USGS Publications Warehouse

Cutler, D.R.; Edwards, T.C.; Beard, K.H.; Cutler, A.; Hess, K.T.; Gibson, J.; Lawler, J.J.

2007-01-01

Classification procedures are some of the most widely used statistical methods in ecology. Random forests (RF) is a new and powerful statistical classifier that is well established in other disciplines but is relatively unknown in ecology. Advantages of RF compared to other statistical classifiers include (1) very high classification accuracy; (2) a novel method of determining variable importance; (3) ability to model complex interactions among predictor variables; (4) flexibility to perform several types of statistical data analysis, including regression, classification, survival analysis, and unsupervised learning; and (5) an algorithm for imputing missing values. We compared the accuracies of RF and four other commonly used statistical classifiers using data on invasive plant species presence in Lava Beds National Monument, California, USA, rare lichen species presence in the Pacific Northwest, USA, and nest sites for cavity nesting birds in the Uinta Mountains, Utah, USA. We observed high classification accuracy in all applications as measured by cross-validation and, in the case of the lichen data, by independent test data, when comparing RF to other common classification methods. We also observed that the variables that RF identified as most important for classifying invasive plant species coincided with expectations based on the literature. ?? 2007 by the Ecological Society of America.

One Bioregion/One Health: An Integrative Narrative for Transboundary Planning along the US–Mexico Border

PubMed Central

PEZZOLI, KEITH; KOZO, JUSTINE; FERRAN, KAREN; WOOTEN, WILMA; GOMEZ, GUDELIA RANGEL; AL-DELAIMY, WAEL K.

2015-01-01

Global megatrends—including climate change, food and water insecurity, economic crisis, large-scale disasters and widespread increases in preventable diseases—are motivating a bioregionalisation of planning in city-regions around the world. Bioregionalisation is an emergent process. It is visible where societies have begun grappling with complex socio-ecological problems by establishing place-based (territorial) approaches to securing health and well-being. This article examines a bioregional effort to merge place-based health planning and ecological restoration along the US–Mexico border. The theoretical construct underpinning this effort is called One Bioregion/One Health (OBROH). OBROH frames health as a transborder phenomenon that involves human-animal-environment interactions. The OBROH approach aims to improve transborder knowledge networking, ecosystem resilience, community participation in science–society relations, leadership development and cross-disciplinary training. It is a theoretically informed narrative to guide action. OBROH is part of a paradigm shift evident worldwide; it is redefining human-ecological relationships in the quest for healthy place making. The article concludes on a forward-looking note about the promise of environmental epidemiology, telecoupling, ecological restoration, the engaged university and bioregional justice as concepts pertinent to reinventing place-based planning. PMID:26097402

Incidental Learning of Melodic Structure of North Indian Music.

PubMed

Rohrmeier, Martin; Widdess, Richard

2017-07-01

Musical knowledge is largely implicit. It is acquired without awareness of its complex rules, through interaction with a large number of samples during musical enculturation. Whereas several studies explored implicit learning of mostly abstract and less ecologically valid features of Western music, very little work has been done with respect to ecologically valid stimuli as well as non-Western music. The present study investigated implicit learning of modal melodic features in North Indian classical music in a realistic and ecologically valid way. It employed a cross-grammar design, using melodic materials from two modes (rāgas) that use the same scale. Findings indicated that Western participants unfamiliar with Indian music incidentally learned to identify distinctive features of each mode. Confidence ratings suggest that participants' performance was consistently correlated with confidence, indicating that they became aware of whether they were right in their responses; that is, they possessed explicit judgment knowledge. Altogether our findings show incidental learning in a realistic ecologically valid context during only a very short exposure, they provide evidence that incidental learning constitutes a powerful mechanism that plays a fundamental role in musical acquisition. Copyright © 2016 Cognitive Science Society, Inc.

Health benefits, ecological threats of low-carbon electricity

NASA Astrophysics Data System (ADS)

Gibon, Thomas; Hertwich, Edgar G.; Arvesen, Anders; Singh, Bhawna; Verones, Francesca

2017-03-01

Stabilizing global temperature will require a shift to renewable or nuclear power from fossil power and the large-scale deployment of CO2 capture and storage (CCS) for remaining fossil fuel use. Non-climate co-benefits of low-carbon energy technologies, especially reduced mortalities from air pollution and decreased ecosystem damage, have been important arguments for policies to reduce CO2 emissions. Taking into account a wide range of environmental mechanisms and the complex interactions of the supply chains of different technologies, we conducted the first life cycle assessment of potential human health and ecological impacts of a global low-carbon electricity scenario. Our assessment indicates strong human health benefits of low-carbon electricity. For ecosystem quality, there is a significant trade-off between reduced pollution and climate impacts and potentially significant ecological impacts from land use associated with increased biopower utilization. Other renewables, nuclear power and CCS show clear ecological benefits, so that the climate mitigation scenario with a relatively low share of biopower has lower ecosystem impacts than the baseline scenario. Energy policy can maximize co-benefits by supporting other renewable and nuclear power and developing biomass supply from sources with low biodiversity impact.

The micro and macro of nutrients across biological scales.

PubMed

Warne, Robin W

2014-11-01

During the past decade, we have gained new insights into the profound effects that essential micronutrients and macronutrients have on biological processes ranging from cellular function, to whole-organism performance, to dynamics in ecological communities, as well as to the structure and function of ecosystems. For example, disparities between intake and organismal requirements for specific nutrients are known to strongly affect animal physiological performance and impose trade-offs in the allocations of resources. However, recent findings have demonstrated that life-history allocation trade-offs and even microevolutionary dynamics may often be a result of molecular-level constraints on nutrient and metabolic processing, in which limiting reactants are routed among competing biochemical pathways. In addition, recent work has shown that complex ecological interactions between organismal physiological states such as exposure to environmental stressors and infectious pathogens can alter organismal requirements for, and, processing of, nutrients, and even alter subsequent nutrient cycling in ecosystems. Furthermore, new research is showing that such interactions, coupled with evolutionary and biogeographical constraints on the biosynthesis and availability of essential nutrients and micronutrients play an important, but still under-studied role in the structuring and functioning of ecosystems. The purpose of this introduction to the symposium "The Micro and Macro of Nutrient Effects in Animal Physiology and Ecology" is to briefly review and highlight recent research that has dramatically advanced our understanding of how nutrients in their varied forms profoundly affect and shape ecological and evolutionary processes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Genome composition and phylogeny of microbes predict their co-occurrence in the environment

PubMed Central

2017-01-01

The genomic information of microbes is a major determinant of their phenotypic properties, yet it is largely unknown to what extent ecological associations between different species can be explained by their genome composition. To bridge this gap, this study introduces two new genome-wide pairwise measures of microbe-microbe interaction. The first (genome content similarity index) quantifies similarity in genome composition between two microbes, while the second (microbe-microbe functional association index) summarizes the topology of a protein functional association network built for a given pair of microbes and quantifies the fraction of network edges crossing organismal boundaries. These new indices are then used to predict co-occurrence between reference genomes from two 16S-based ecological datasets, accounting for phylogenetic relatedness of the taxa. Phylogenetic relatedness was found to be a strong predictor of ecological associations between microbes which explains about 10% of variance in co-occurrence data, but genome composition was found to be a strong predictor as well, it explains up to 4% the variance in co-occurrence when all genomic-based indices are used in combination, even after accounting for evolutionary relationships between the species. On their own, the metrics proposed here explain a larger proportion of variance than previously reported more complex methods that rely on metabolic network comparisons. In summary, results of this study indicate that microbial genomes do indeed contain detectable signal of organismal ecology, and the methods described in the paper can be used to improve mechanistic understanding of microbe-microbe interactions. PMID:28152007

[Some comments on ecological field].

PubMed

Wang, D

2000-06-01

Based on the data of plant ecological field studies, this paper reviewed the conception of ecological field, field eigenfunctions, graphs of ecological field and its application of ecological field theory in explaining plant interactions. It is suggested that the basic character of ecological field is material, and based on the current research level, it is not sure whether ecological field is a kind of specific field different from general physical field. The author gave some comments on the formula and estimation of parameters of basic field function-ecological potential model on ecological field. Both models have their own characteristics and advantages in specific conditions. The author emphasized that ecological field had even more meaning of ecological methodology, and applying ecological field theory in describing the types and processes of plant interactions had three characteristics: quantitative, synthetic and intuitionistic. Field graphing might provide a new way to ecological studies, especially applying the ecological field theory might give an appropriate quantitative explanation for the dynamic process of plant populations (coexistence and interference competition).

Control of multidimensional systems on complex network

PubMed Central

Bagnoli, Franco; Battistelli, Giorgio; Chisci, Luigi; Fanelli, Duccio

2017-01-01

Multidimensional systems coupled via complex networks are widespread in nature and thus frequently invoked for a large plethora of interesting applications. From ecology to physics, individual entities in mutual interactions are grouped in families, homogeneous in kind. These latter interact selectively, through a sequence of self-consistently regulated steps, whose deeply rooted architecture is stored in the assigned matrix of connections. The asymptotic equilibrium eventually attained by the system, and its associated stability, can be assessed by employing standard nonlinear dynamics tools. For many practical applications, it is however important to externally drive the system towards a desired equilibrium, which is resilient, hence stable, to external perturbations. To this end we here consider a system made up of N interacting populations which evolve according to general rate equations, bearing attributes of universality. One species is added to the pool of interacting families and used as a dynamical controller to induce novel stable equilibria. Use can be made of the root locus method to shape the needed control, in terms of intrinsic reactivity and adopted protocol of injection. The proposed method is tested on both synthetic and real data, thus enabling to demonstrate its robustness and versatility. PMID:28892493

Interactive Videos Enhance Learning about Socio-Ecological Systems

ERIC Educational Resources Information Center

Smithwick, Erica; Baxter, Emily; Kim, Kyung; Edel-Malizia, Stephanie; Rocco, Stevie; Blackstock, Dean

2018-01-01

Two forms of interactive video were assessed in an online course focused on conservation. The hypothesis was that interactive video enhances student perceptions about learning and improves mental models of social-ecological systems. Results showed that students reported greater learning and attitudes toward the subject following interactive video.…

The Amazing Ecology of Terrestrial Isopods

ERIC Educational Resources Information Center

Dobson, Christopher; Postema, Dan

2014-01-01

Ecology is the study of how organisms interact with their environment, and the best place to see these interactions is outside in natural habitats. Pillbugs (roly-polies) provide an excellent opportunity for students to learn ecological concepts through inquiry. Because of their fascinating behaviors, pillbugs are ideal organisms to introduce…

The ecologies of community caring.

PubMed

Bent, K N

1999-06-01

Caring has been called the interactive exemplar of nursing in that it relates other foundational concepts of person, health, and environment within the profession and discipline. However, to reflect the dynamic praxis of knowing, being, and doing that is community health nursing, caring must include a focus on communities, the environment, and the global society. The concepts of community and community interventions remain complex and difficult, thus, community caring remains unclear. This article will explore the concept and offer a model of caring praxis in community health nursing.

Global climate change and vector-borne diseases

USGS Publications Warehouse

Ginsberg, H.S.

2002-01-01

Global warming will have different effects on different diseases because of the complex and idiosynchratic interactions between vectors, hosts, and pathogens that influence transmission dynamics of each pathogen. Human activities, including urbanization, rapid global travel, and vector management, have profound effects on disease transmission that can operate on more rapid time scales than does global climate change. The general concern about global warming encouraging the spread of tropical diseases is legitimate, but the effects vary among diseases, and the ecological implications are difficult to predict.

Geography, environment and organismal traits in the diversification of a major tropical herbaceous angiosperm radiation

PubMed Central

2018-01-01

Abstract The generation of plant diversity involves complex interactions between geography, environment and organismal traits. Many macroevolutionary processes and emergent patterns have been identified in different plant groups through the study of spatial data, but rarely in the context of a large radiation of tropical herbaceous angiosperms. A powerful system for testing interrelated biogeographical hypotheses is provided by the terrestrial bromeliads, a Neotropical group of extensive ecological diversity and importance. In this investigation, distributional data for 564 species of terrestrial bromeliads were used to estimate variation in the position and width of species-level hydrological habitat occupancy and test six core hypotheses linking geography, environment and organismal traits. Taxonomic groups and functional types differed in hydrological habitat occupancy, modulated by convergent and divergent trait evolution, and with contrasting interactions with precipitation abundance and seasonality. Plant traits in the Bromeliaceae are intimately associated with bioclimatic differentiation, which is in turn strongly associated with variation in geographical range size and species richness. These results emphasize the ecological relevance of structural-functional innovation in a major plant radiation. PMID:29479409

Ecology as a Unifying Theme for Home Economics/Human Ecology.

ERIC Educational Resources Information Center

Vaines, Eleanore

1994-01-01

Discusses the complex character of everyday life as the deep ecology of Home Economics/Human Ecology. Explores the meanings of ecology and the ways in which diversity and harmony are interrelated companions of dynamic living systems. (JOW)

Enabling Controlling Complex Networks with Local Topological Information.

PubMed

Li, Guoqi; Deng, Lei; Xiao, Gaoxi; Tang, Pei; Wen, Changyun; Hu, Wuhua; Pei, Jing; Shi, Luping; Stanley, H Eugene

2018-03-15

Complex networks characterize the nature of internal/external interactions in real-world systems including social, economic, biological, ecological, and technological networks. Two issues keep as obstacles to fulfilling control of large-scale networks: structural controllability which describes the ability to guide a dynamical system from any initial state to any desired final state in finite time, with a suitable choice of inputs; and optimal control, which is a typical control approach to minimize the cost for driving the network to a predefined state with a given number of control inputs. For large complex networks without global information of network topology, both problems remain essentially open. Here we combine graph theory and control theory for tackling the two problems in one go, using only local network topology information. For the structural controllability problem, a distributed local-game matching method is proposed, where every node plays a simple Bayesian game with local information and local interactions with adjacent nodes, ensuring a suboptimal solution at a linear complexity. Starring from any structural controllability solution, a minimizing longest control path method can efficiently reach a good solution for the optimal control in large networks. Our results provide solutions for distributed complex network control and demonstrate a way to link the structural controllability and optimal control together.

How the biodiversity sciences may aid biological tools and ecological engineering to assess the impact of climatic changes.

PubMed

Morand, S; Guégan, J-F

2008-08-01

This paper addresses how climate changes interact with other global changes caused by humans (habitat fragmentation, changes in land use, bioinvasions) to affect biodiversity. Changes in biodiversity at all levels (genetic, population and community) affect the functioning of ecosystems, in particular host-pathogen interactions, with major consequences in health ecology (emergence and re-emergence; the evolution of virulence and resistance). In this paper, the authors demonstrate that the biodiversity sciences, epidemiological theory and evolutionary ecology are indispensable in assessing the impact of climate changes, and also for modelling the evolution of host-pathogen interactions in a changing environment. The next step is to apply health ecology to the science of ecological engineering.

Avoiding decline: Fostering resilience and sustainability in midsize cities

USGS Publications Warehouse

Allen, Craig R.; Birge, Hannah E.; Bartelt-Hunt, Shannon; Bevans, Rebecca A.; Burnett, Jessica L.; Cosens, Barbara; Cai, Ximing; Garmestani, Ahjond S.; Linkov, Igor; Scott, Elizabeth A.; Solomon, Mark D.; Uden, Daniel R.

2016-01-01

Eighty-five percent of United States citizens live in urban areas. However, research surrounding the resilience and sustainability of complex urban systems focuses largely on coastal megacities (>1 million people). Midsize cities differ from their larger counterparts due to tight urban-rural feedbacks with their immediate natural environments that result from heavy reliance and close management of local ecosystem services. They also may be less path-dependent than larger cities due to shorter average connection length among system components, contributing to higher responsiveness among social, infrastructural, and ecological feedbacks. These distinct midsize city features call for a framework that organizes information and concepts concerning the sustainability of midsize cities specifically. We argue that an integrative approach is necessary to capture properties emergent from the complex interactions of the social, infrastructural, and ecological subsystems that comprise a city system. We suggest approaches to estimate the relative resilience of midsize cities, and include an example assessment to illustrate one such estimation approach. Resilience assessments of a midsize city can be used to examine why some cities end up on sustainable paths while others diverge to unsustainable paths, and which feedbacks may be partially responsible. They also provide insight into how city planners and decision makers can use information about the resilience of midsize cities undergoing growth or shrinkage relative to their larger and smaller counterparts, to transform them into long-term, sustainable social-ecological systems.

Evidence-based control of canine rabies: a critical review of population density reduction.

PubMed

Morters, Michelle K; Restif, Olivier; Hampson, Katie; Cleaveland, Sarah; Wood, James L N; Conlan, Andrew J K

2013-01-01

Control measures for canine rabies include vaccination and reducing population density through culling or sterilization. Despite the evidence that culling fails to control canine rabies, efforts to reduce canine population density continue in many parts of the world. The rationale for reducing population density is that rabies transmission is density-dependent, with disease incidence increasing directly with host density. This may be based, in part, on an incomplete interpretation of historical field data for wildlife, with important implications for disease control in dog populations. Here, we examine historical and more recent field data, in the context of host ecology and epidemic theory, to understand better the role of density in rabies transmission and the reasons why culling fails to control rabies. We conclude that the relationship between host density, disease incidence and other factors is complex and may differ between species. This highlights the difficulties of interpreting field data and the constraints of extrapolations between species, particularly in terms of control policies. We also propose that the complex interactions between dogs and people may render culling of free-roaming dogs ineffective irrespective of the relationship between host density and disease incidence. We conclude that vaccination is the most effective means to control rabies in all species. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

Insights into the Ecology and Evolution of Polyploid Plants through Network Analysis.

PubMed

Gallagher, Joseph P; Grover, Corrinne E; Hu, Guanjing; Wendel, Jonathan F

2016-06-01

Polyploidy is a widespread phenomenon throughout eukaryotes, with important ecological and evolutionary consequences. Although genes operate as components of complex pathways and networks, polyploid changes in genes and gene expression have typically been evaluated as either individual genes or as a part of broad-scale analyses. Network analysis has been fruitful in associating genomic and other 'omic'-based changes with phenotype for many systems. In polyploid species, network analysis has the potential not only to facilitate a better understanding of the complex 'omic' underpinnings of phenotypic and ecological traits common to polyploidy, but also to provide novel insight into the interaction among duplicated genes and genomes. This adds perspective to the global patterns of expression (and other 'omic') change that accompany polyploidy and to the patterns of recruitment and/or loss of genes following polyploidization. While network analysis in polyploid species faces challenges common to other analyses of duplicated genomes, present technologies combined with thoughtful experimental design provide a powerful system to explore polyploid evolution. Here, we demonstrate the utility and potential of network analysis to questions pertaining to polyploidy with an example involving evolution of the transgressively superior cotton fibres found in polyploid Gossypium hirsutum. By combining network analysis with prior knowledge, we provide further insights into the role of profilins in fibre domestication and exemplify the potential for network analysis in polyploid species. © 2016 John Wiley & Sons Ltd.

A cognitive prosthesis for complex decision-making.

PubMed

Tremblay, Sébastien; Gagnon, Jean-François; Lafond, Daniel; Hodgetts, Helen M; Doiron, Maxime; Jeuniaux, Patrick P J M H

2017-01-01

While simple heuristics can be ecologically rational and effective in naturalistic decision making contexts, complex situations require analytical decision making strategies, hypothesis-testing and learning. Sub-optimal decision strategies - using simplified as opposed to analytic decision rules - have been reported in domains such as healthcare, military operational planning, and government policy making. We investigate the potential of a computational toolkit called "IMAGE" to improve decision-making by developing structural knowledge and increasing understanding of complex situations. IMAGE is tested within the context of a complex military convoy management task through (a) interactive simulations, and (b) visualization and knowledge representation capabilities. We assess the usefulness of two versions of IMAGE (desktop and immersive) compared to a baseline. Results suggest that the prosthesis helped analysts in making better decisions, but failed to increase their structural knowledge about the situation once the cognitive prosthesis is removed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Complexity in models of cultural niche construction with selection and homophily.

PubMed

Creanza, Nicole; Feldman, Marcus W

2014-07-22

Niche construction is the process by which organisms can alter the ecological environment for themselves, their descendants, and other species. As a result of niche construction, differences in selection pressures may be inherited across generations. Homophily, the tendency of like phenotypes to mate or preferentially associate, influences the evolutionary dynamics of these systems. Here we develop a model that includes selection and homophily as independent culturally transmitted traits that influence the fitness and mate choice determined by another focal cultural trait. We study the joint dynamics of a focal set of beliefs, a behavior that can differentially influence the fitness of those with certain beliefs, and a preference for partnering based on similar beliefs. Cultural transmission, selection, and homophily interact to produce complex evolutionary dynamics, including oscillations, stable polymorphisms of all cultural phenotypes, and simultaneous stability of oscillation and fixation, which have not previously been observed in models of cultural evolution or gene-culture interactions. We discuss applications of this model to the interaction of beliefs and behaviors regarding education, contraception, and animal domestication.

A socio-ecological perspective of access to and acceptability of HIV/AIDS treatment and care services: a qualitative case study research.

PubMed

Yakob, Bereket; Ncama, Busisiwe Purity

2016-02-16

Access to healthcare is an essential element of health development and a fundamental human right. While access to and acceptability of healthcare are complex concepts that interact with different socio-ecological factors (individual, community, institutional and policy), it is not known how these factors affect HIV care. This study investigated the impact of socio-ecological factors on access to and acceptability of HIV/AIDS treatment and care services (HATCS) in Wolaita Zone of Ethiopia. Qualitative case study research was conducted in six woredas (districts). Focus group discussions (FGDs) were conducted with 68 participants in 11 groups (six with people using antiretroviral therapy (ART) and five with general community members). Key informant interviews (KIIs) were conducted with 28 people involved in HIV care, support services and health administration at different levels. Individual in-depth interviews (IDIs) were conducted with eight traditional healers and seven defaulters from (ART). NVIVO 10 was used to assist qualitative content data analysis. A total of 111 people participated in the study, of which 51 (45.9%) were male and 60 (54.1%) were female, while 58 (53.3%) and 53 (47.7%) were urban and rural residents, respectively. The factors that affect access to and acceptability of HATCS were categorized in four socio-ecological units of analysis: client-based factors (awareness, experiences, expectations, income, employment, family, HIV disclosure and food availability); community-based factors (care and support, stigma and discrimination and traditional healing); health facility-based factors (interactions with care providers, availability of care, quality of care, distance, affordability, logistics availability, follow up and service administration); and policy and standards (healthcare financing, service standards, implementation manuals and policy documents). A socio-ecological perspective provides a useful framework to investigate the interplay among multilevel and interactive factors that impact on access to and acceptability of HATCS such as clients, community, institution and policy. Planners, resource allocators and implementers could consider these factors during planning, implementation and evaluation of HATCS. Further study is required to confirm the findings.

A framework for complexity in palliative care: A qualitative study with patients, family carers and professionals.

PubMed

Pask, Sophie; Pinto, Cathryn; Bristowe, Katherine; van Vliet, Liesbeth; Nicholson, Caroline; Evans, Catherine J; George, Rob; Bailey, Katharine; Davies, Joanna M; Guo, Ping; Daveson, Barbara A; Higginson, Irene J; Murtagh, Fliss Em

2018-06-01

Palliative care patients are often described as complex but evidence on complexity is limited. We need to understand complexity, including at individual patient-level, to define specialist palliative care, characterise palliative care populations and meaningfully compare interventions/outcomes. To explore palliative care stakeholders' views on what makes a patient more or less complex and insights on capturing complexity at patient-level. In-depth qualitative interviews, analysed using Framework analysis. Semi-structured interviews across six UK centres with patients, family, professionals, managers and senior leads, purposively sampled by experience, background, location and setting (hospital, hospice and community). 65 participants provided an understanding of complexity, which extended far beyond the commonly used physical, psychological, social and spiritual domains. Complexity included how patients interact with family/professionals, how services' respond to needs and societal perspectives on care. 'Pre-existing', 'cumulative' and 'invisible' complexity are further important dimensions to delivering effective palliative and end-of-life care. The dynamic nature of illness and needs over time was also profoundly influential. Adapting Bronfenbrenner's Ecological Systems Theory, we categorised findings into the microsystem (person, needs and characteristics), chronosystem (dynamic influences of time), mesosystem (interactions with family/health professionals), exosystem (palliative care services/systems) and macrosystem (societal influences). Stakeholders found it acceptable to capture complexity at the patient-level, with perceived benefits for improving palliative care resource allocation. Our conceptual framework encompasses additional elements beyond physical, psychological, social and spiritual domains and advances systematic understanding of complexity within the context of palliative care. This framework helps capture patient-level complexity and target resource provision in specialist palliative care.

The feasibility and stability of large complex biological networks: a random matrix approach.

PubMed

Stone, Lewi

2018-05-29

In the 70's, Robert May demonstrated that complexity creates instability in generic models of ecological networks having random interaction matrices A. Similar random matrix models have since been applied in many disciplines. Central to assessing stability is the "circular law" since it describes the eigenvalue distribution for an important class of random matrices A. However, despite widespread adoption, the "circular law" does not apply for ecological systems in which density-dependence operates (i.e., where a species growth is determined by its density). Instead one needs to study the far more complicated eigenvalue distribution of the community matrix S = DA, where D is a diagonal matrix of population equilibrium values. Here we obtain this eigenvalue distribution. We show that if the random matrix A is locally stable, the community matrix S = DA will also be locally stable, providing the system is feasible (i.e., all species have positive equilibria D > 0). This helps explain why, unusually, nearly all feasible systems studied here are locally stable. Large complex systems may thus be even more fragile than May predicted, given the difficulty of assembling a feasible system. It was also found that the degree of stability, or resilience of a system, depended on the minimum equilibrium population.

Living Organisms Author Their Read-Write Genomes in Evolution

PubMed Central

2017-01-01

Evolutionary variations generating phenotypic adaptations and novel taxa resulted from complex cellular activities altering genome content and expression: (i) Symbiogenetic cell mergers producing the mitochondrion-bearing ancestor of eukaryotes and chloroplast-bearing ancestors of photosynthetic eukaryotes; (ii) interspecific hybridizations and genome doublings generating new species and adaptive radiations of higher plants and animals; and, (iii) interspecific horizontal DNA transfer encoding virtually all of the cellular functions between organisms and their viruses in all domains of life. Consequently, assuming that evolutionary processes occur in isolated genomes of individual species has become an unrealistic abstraction. Adaptive variations also involved natural genetic engineering of mobile DNA elements to rewire regulatory networks. In the most highly evolved organisms, biological complexity scales with “non-coding” DNA content more closely than with protein-coding capacity. Coincidentally, we have learned how so-called “non-coding” RNAs that are rich in repetitive mobile DNA sequences are key regulators of complex phenotypes. Both biotic and abiotic ecological challenges serve as triggers for episodes of elevated genome change. The intersections of cell activities, biosphere interactions, horizontal DNA transfers, and non-random Read-Write genome modifications by natural genetic engineering provide a rich molecular and biological foundation for understanding how ecological disruptions can stimulate productive, often abrupt, evolutionary transformations. PMID:29211049

Living Organisms Author Their Read-Write Genomes in Evolution.

PubMed

Shapiro, James A

2017-12-06

Evolutionary variations generating phenotypic adaptations and novel taxa resulted from complex cellular activities altering genome content and expression: (i) Symbiogenetic cell mergers producing the mitochondrion-bearing ancestor of eukaryotes and chloroplast-bearing ancestors of photosynthetic eukaryotes; (ii) interspecific hybridizations and genome doublings generating new species and adaptive radiations of higher plants and animals; and, (iii) interspecific horizontal DNA transfer encoding virtually all of the cellular functions between organisms and their viruses in all domains of life. Consequently, assuming that evolutionary processes occur in isolated genomes of individual species has become an unrealistic abstraction. Adaptive variations also involved natural genetic engineering of mobile DNA elements to rewire regulatory networks. In the most highly evolved organisms, biological complexity scales with "non-coding" DNA content more closely than with protein-coding capacity. Coincidentally, we have learned how so-called "non-coding" RNAs that are rich in repetitive mobile DNA sequences are key regulators of complex phenotypes. Both biotic and abiotic ecological challenges serve as triggers for episodes of elevated genome change. The intersections of cell activities, biosphere interactions, horizontal DNA transfers, and non-random Read-Write genome modifications by natural genetic engineering provide a rich molecular and biological foundation for understanding how ecological disruptions can stimulate productive, often abrupt, evolutionary transformations.

Using diel movement behavior to infer foraging strategies related to ecological and social factors in elephants.

PubMed

Polansky, Leo; Douglas-Hamilton, Iain; Wittemyer, George

2013-01-01

Adaptive movement behaviors allow individuals to respond to fluctuations in resource quality and distribution in order to maintain fitness. Classically, studies of the interaction between ecological conditions and movement behavior have focused on such metrics as travel distance, velocity, home range size or patch occupancy time as the salient metrics of behavior. Driven by the emergence of very regular high frequency data, more recently the importance of interpreting the autocorrelation structure of movement as a behavioral metric has become apparent. Studying movement of a free ranging African savannah elephant population, we evaluated how two movement metrics, diel displacement (DD) and movement predictability (MP - the degree of autocorrelated movement activity at diel time scales), changed in response to variation in resource availability as measured by the Normalized Difference Vegetation Index. We were able to capitalize on long term (multi-year) yet high resolution (hourly) global positioning system tracking datasets, the sample size of which allows robust analysis of complex models. We use optimal foraging theory predictions as a framework to interpret our results, in particular contrasting the behaviors across changes in social rank and resource availability to infer which movement behaviors at diel time scales may be optimal in this highly social species. Both DD and MP increased with increasing forage availability, irrespective of rank, reflecting increased energy expenditure and movement predictability during time periods of overall high resource availability. However, significant interactions between forage availability and social rank indicated a stronger response in DD, and a weaker response in MP, with increasing social status. Relative to high ranking individuals, low ranking individuals expended more energy and exhibited less behavioral movement autocorrelation during lower forage availability conditions, likely reflecting sub-optimal movement behavior. Beyond situations of contest competition, rank status appears to influence the extent to which individuals can modify their movement strategies across periods with differing forage availability. Large-scale spatiotemporal resource complexity not only impacts fine scale movement and optimal foraging strategies directly, but likely impacts rates of inter- and intra-specific interactions and competition resulting in socially based movement responses to ecological dynamics.

The effects of tectonic deformation and sediment allocation on shelf habitats and megabenthic distribution and diversity in southern California

NASA Astrophysics Data System (ADS)

Switzer, Ryan D.; Parnell, P. Ed; Leichter, James L.; Driscoll, Neal W.

2016-02-01

Landscape and seascape structures are typically complex and manifest as patch mosaics within characteristic biomes, bordering one another in gradual or abrupt ecotones. The underlying patch structure in coastal shelf ecosystems is driven by the interaction of tectonic, sedimentary, and sea level dynamic processes. Animals and plants occupy and interact within these mosaics. Terrestrial landscape ecological studies have shown that patch structure is important for ecological processes such as foraging, connectivity, predation, and species dynamics. The importance of patch structure for marine systems is less clear because far fewer pattern-process studies have been conducted in these systems. For many coastal shelf systems, there is a paucity of information on how species occupy shelf seascapes, particularly for seascapes imbued with complex patch structure and ecotones that are common globally due to tectonic activity. Here, we present the results of a study conducted along a myriameter-scale gradient of bottom and sub-bottom geological forcing altered by tectonic deformation, sea level transgression and sediment allocation. The resulting seascape is dominated by unconsolidated sediments throughout, but also exhibits increasing density and size of outcropping patches along a habitat patch gradient forced by the erosion of a sea level transgressive surface that has been deformed and tilted by tectonic forcing. A combination of sub-bottom profiling, multibeam bathymetry, and ROV surveys of the habitats and the demersal megafauna occupying the habitats indicate (1) significant beta diversity along this gradient, (2) biological diversity does not scale with habitat diversity, and (3) species occupy the patches disproportionately (non-linearly) with regard to the proportional availability of their preferred habitats. These results indicate that shelf habitat patch structure modulates species specific processes and interactions with other species. Further studies are needed to examine experimentally the mechanics of how patch structure modulates ecological processes in shelf systems. Our results also provide further support for including multiple spatial scales of patch structure for the application of remote habitat sensing as a surrogate for biological community structure.

Ecophysiology meets conservation: understanding the role of disease in amphibian population declines

PubMed Central

Blaustein, Andrew R.; Gervasi, Stephanie S.; Johnson, Pieter T. J.; Hoverman, Jason T.; Belden, Lisa K.; Bradley, Paul W.; Xie, Gisselle Y.

2012-01-01

Infectious diseases are intimately associated with the dynamics of biodiversity. However, the role that infectious disease plays within ecological communities is complex. The complex effects of infectious disease at the scale of communities and ecosystems are driven by the interaction between host and pathogen. Whether or not a given host–pathogen interaction results in progression from infection to disease is largely dependent on the physiological characteristics of the host within the context of the external environment. Here, we highlight the importance of understanding the outcome of infection and disease in the context of host ecophysiology using amphibians as a model system. Amphibians are ideal for such a discussion because many of their populations are experiencing declines and extinctions, with disease as an important factor implicated in many declines and extinctions. Exposure to pathogens and the host's responses to infection can be influenced by many factors related to physiology such as host life history, immunology, endocrinology, resource acquisition, behaviour and changing climates. In our review, we discuss the relationship between disease and biodiversity. We highlight the dynamics of three amphibian host–pathogen systems that induce different effects on hosts and life stages and illustrate the complexity of amphibian–host–parasite systems. We then review links between environmental stress, endocrine–immune interactions, disease and climate change. PMID:22566676

Serious games experiment toward agent-based simulation

USGS Publications Warehouse

Wein, Anne; Labiosa, William

2013-01-01

We evaluate the potential for serious games to be used as a scientifically based decision-support product that supports the United States Geological Survey’s (USGS) mission--to provide integrated, unbiased scientific information that can make a substantial contribution to societal well-being for a wide variety of complex environmental challenges. Serious or pedagogical games are an engaging way to educate decisionmakers and stakeholders about environmental challenges that are usefully informed by natural and social scientific information and knowledge and can be designed to promote interactive learning and exploration in the face of large uncertainties, divergent values, and complex situations. We developed two serious games that use challenging environmental-planning issues to demonstrate and investigate the potential contributions of serious games to inform regional-planning decisions. Delta Skelta is a game emulating long-term integrated environmental planning in the Sacramento-San Joaquin Delta, California, that incorporates natural hazards (flooding and earthquakes) and consequences for California water supplies amidst conflicting water interests. Age of Ecology is a game that simulates interactions between economic and ecologic processes, as well as natural hazards while implementing agent-based modeling. The content of these games spans the USGS science mission areas related to water, ecosystems, natural hazards, land use, and climate change. We describe the games, reflect on design and informational aspects, and comment on their potential usefulness. During the process of developing these games, we identified various design trade-offs involving factual information, strategic thinking, game-winning criteria, elements of fun, number and type of players, time horizon, and uncertainty. We evaluate the two games in terms of accomplishments and limitations. Overall, we demonstrated the potential for these games to usefully represent scientific information within challenging environmental and ecosystem-management contexts and to provide an interactive way of learning about the complexity of interactions between people and natural systems. Further progress on the use of pedagogical games to fulfill the USGS mission will require collaboration among scientists, game developers, educators, and stakeholders. We conclude that as the USGS positions itself to communicate and convey the results of multiple science strategies, including natural-resource security and sustainability, pedagogical game development and agent-based modeling offer a means to (1) establish interdisciplinary and collaborative teams with a focused integrated outcome; (2) contribute to the modeling of interaction, feedback, and adaptation of ecosystems; and (3) enable social learning through a broadly appealing and increasingly sophisticated medium.

Interactions between toxic chemicals and natural environmental factors--a meta-analysis and case studies.

PubMed

Laskowski, Ryszard; Bednarska, Agnieszka J; Kramarz, Paulina E; Loureiro, Susana; Scheil, Volker; Kudłek, Joanna; Holmstrup, Martin

2010-08-15

The paper addresses problems arising from effects of natural environmental factors on toxicity of pollutants to organisms. Most studies on interactions between toxicants and natural factors, including those completed in the EU project NoMiracle (Novel Methods for Integrated Risk Assessment of Cumulative Stressors in Europe) described herein, showed that effects of toxic chemicals on organisms can differ vastly depending purely on external conditions. We compiled data from 61 studies on effects of temperature, moisture and dissolved oxygen on toxicity of a range of chemicals representing pesticides, polycyclic aromatic hydrocarbons, plant protection products of bacterial origin and trace metals. In 62.3% cases significant interactions (p< or =0.05 or less) between natural factors and chemicals were found, reaching 100% for the effect of dissolved oxygen on toxicity of waterborne chemicals. The meta-analysis of the 61 studies showed that the null hypothesis assuming no interactions between toxic chemicals and natural environmental factors should be rejected at p=2.7 x 10(-82) (truncated product method probability). In a few cases of more complex experimental designs, also second-order interactions were found, indicating that natural factors can modify interactions among chemicals. Such data emphasize the necessity of including information on natural factors and their variation in time and across geographic regions in ecological risk assessment. This can be done only if appropriate ecotoxicological test designs are used, in which test organisms are exposed to toxicants at a range of environmental conditions. We advocate designing such tests for the second-tier ecological risk assessment procedures. Copyright 2010 Elsevier B.V. All rights reserved.

Dynamic Assessment of Microbial Ecology (DAME): A web app for interactive analysis and visualization of microbial sequencing data

USDA-ARS?s Scientific Manuscript database

Dynamic Assessment of Microbial Ecology (DAME) is a shiny-based web application for interactive analysis and visualization of microbial sequencing data. DAME provides researchers not familiar with R programming the ability to access the most current R functions utilized for ecology and gene sequenci...

Experiential Learning as a Constraint-Led Process: An Ecological Dynamics Perspective

ERIC Educational Resources Information Center

Brymer, Eric; Davids, Keith

2014-01-01

In this paper we present key ideas for an ecological dynamics approach to learning that reveal the importance of learner-environment interactions to frame outdoor experiential learning. We propose that ecological dynamics provides a useful framework for understanding the interacting constraints of the learning process and for designing learning…

A Model to Explain Plant Growth Promotion Traits: A Multivariate Analysis of 2,211 Bacterial Isolates

PubMed Central

da Costa, Pedro Beschoren; Granada, Camille E.; Ambrosini, Adriana; Moreira, Fernanda; de Souza, Rocheli; dos Passos, João Frederico M.; Arruda, Letícia; Passaglia, Luciane M. P.

2014-01-01

Plant growth-promoting bacteria can greatly assist sustainable farming by improving plant health and biomass while reducing fertilizer use. The plant-microorganism-environment interaction is an open and complex system, and despite the active research in the area, patterns in root ecology are elusive. Here, we simultaneously analyzed the plant growth-promoting bacteria datasets from seven independent studies that shared a methodology for bioprospection and phenotype screening. The soil richness of the isolate's origin was classified by a Principal Component Analysis. A Categorical Principal Component Analysis was used to classify the soil richness according to isolate's indolic compound production, siderophores production and phosphate solubilization abilities, and bacterial genera composition. Multiple patterns and relationships were found and verified with nonparametric hypothesis testing. Including niche colonization in the analysis, we proposed a model to explain the expression of bacterial plant growth-promoting traits according to the soil nutritional status. Our model shows that plants favor interaction with growth hormone producers under rich nutrient conditions but favor nutrient solubilizers under poor conditions. We also performed several comparisons among the different genera, highlighting interesting ecological interactions and limitations. Our model could be used to direct plant growth-promoting bacteria bioprospection and metagenomic sampling. PMID:25542031

Wild-captive interactions and economics drive dynamics of Asian elephants in Laos.

PubMed

Maurer, Gilles; Rashford, Benjamin S; Chanthavong, Vatsana; Mulot, Baptiste; Gimenez, Olivier

2017-11-01

The interactions between wild and captive populations of Asian elephants (Elephas maximus) persist in most countries of the species distribution, notably through the reproduction between captive females and wild males. However, these complex interactions have been poorly studied, despite their relevance for conservation of this endangered species. Laos has a centuries-long tradition of raising Asian elephants. Besides being cultural icons, captive elephants are inextricably linked to economics through their work in forestry. Using an ecological-economic model, we investigated the effect of socio-economic strategies on fecundity of the Lao population whose dynamics is shaped by human practices. We demonstrated that fecundity is impacted by: i) the dynamics of the wild elephant pool through mating of captive females by wild males, and ii) the financial incentive of elephant owners to breed their animals. As a result, we expect fecundity to rise in response to increases in elephant prices. The captive population will tend towards an asymptotic limit determined by the wild pool growth rate. However, the population will tend to extinction if exports continue. Our ecological-economic approach, by accounting for economic incentives, allows us to predict new equilibria that can serve as a baseline for designing sustainable management strategies for the species.

Improving Ecological Forecasting: Data Assimilation Enhances the Ecological Forecast Horizon of a Complex Food Web

NASA Astrophysics Data System (ADS)

Massoud, E. C.; Huisman, J.; Benincà, E.; Bouten, W.; Vrugt, J. A.

2017-12-01

Species abundances in ecological communities can display chaotic non-equilibrium dynamics. A characteristic feature of chaotic systems is that long-term prediction of the system's trajectory is fundamentally impossible. How then should we make predictions for complex multi-species communities? We explore data assimilation (DA) with the Ensemble Kalman Filter (EnKF) to fuse a two-predator-two-prey model with abundance data from a long term experiment of a plankton community which displays chaotic dynamics. The results show that DA improves substantially the predictability and ecological forecast horizon of complex community dynamics. In addition, we show that DA helps provide guidance on measurement design, for instance on defining the frequency of observations. The study presented here is highly innovative, because DA methods at the current stage are almost unknown in ecology.

Quorum sensing is a language of chemical signals and plays an ecological role in algal-bacterial interactions

PubMed Central

Zhou, Jin; Lyu, Yihua; Richlen, Mindy; Anderson, Donald M.; Cai, Zhonghua

2017-01-01

Algae are ubiquitous in the marine environment, and the ways in which they interact with bacteria are of particular interest in marine ecology field. The interactions between primary producers and bacteria impact the physiology of both partners, alter the chemistry of their environment, and shape microbial diversity. Although algal-bacterial interactions are well known and studied, information regarding the chemical-ecological role of this relationship remains limited, particularly with respect to quorum sensing (QS), which is a system of stimuli and response correlated to population density. In the microbial biosphere, QS is pivotal in driving community structure and regulating behavioral ecology, including biofilm formation, virulence, antibiotic resistance, swarming motility, and secondary metabolite production. Many marine habitats, such as the phycosphere, harbour diverse populations of microorganisms and various signal languages (such as QS-based autoinducers). QS-mediated interactions widely influence algal-bacterial symbiotic relationships, which in turn determine community organization, population structure, and ecosystem functioning. Understanding infochemicals-mediated ecological processes may shed light on the symbiotic interactions between algae host and associated microbes. In this review, we summarize current achievements about how QS modulates microbial behavior, affects symbiotic relationships, and regulates phytoplankton chemical ecological processes. Additionally, we present an overview of QS-modulated co-evolutionary relationships between algae and bacterioplankton, and consider the potential applications and future perspectives of QS. PMID:28966438

From metabolism to ecology: cross-feeding interactions shape the balance between polymicrobial conflict and mutualism

PubMed Central

Estrela, Sylvie; Trisos, Christopher H.; Brown, Sam P.

2012-01-01

Polymicrobial interactions are widespread in nature, and play a major role in maintaining human health and ecosystems. Whenever one organism uses metabolites produced by another organism as energy or nutrient sources, this is called cross-feeding. The ecological outcomes of cross-feeding interactions are poorly understood and potentially diverse: mutualism, competition, exploitation or commensalism. A major reason for this uncertainty is the lack of theoretical approaches linking microbial metabolism to microbial ecology. To address this issue, we explore the dynamics of a one-way interspecific cross-feeding interaction, in which food can be traded for a service (detoxification). Our results show that diverse ecological interactions (competition, mutualism, exploitation) can emerge from this simple cross-feeding interaction, and can be predicted by the metabolic, demographic and environmental parameters that govern the balance of the costs and benefits of association. In particular, our model predicts stronger mutualism for intermediate by-product toxicity because the resource-service exchange is constrained to the service being neither too vital (high toxicity impairs resource provision) nor dispensable (low toxicity reduces need for service). These results support the idea that bridging microbial ecology and metabolism is a critical step towards a better understanding of the factors governing the emergence and dynamics of polymicrobial interactions. PMID:23070318

Phenotypic plasticity in a complex world: interactive effects of food and temperature on fitness components of a seed beetle.

PubMed

Stillwell, R Craig; Wallin, William G; Hitchcock, Lisa J; Fox, Charles W

2007-08-01

Most studies of phenotypic plasticity investigate the effects of an individual environmental factor on organism phenotypes. However, organisms exist in an ecologically complex world where multiple environmental factors can interact to affect growth, development and life histories. Here, using a multifactorial experimental design, we examine the separate and interactive effects of two environmental factors, rearing host species (Vigna radiata, Vigna angularis and Vigna unguiculata) and temperature (20, 25, 30 and 35 degrees C), on growth and life history traits in two populations [Burkina Faso (BF) and South India (SI)] of the seed beetle, Callosobruchus maculatus. The two study populations of beetles responded differently to both rearing host and temperature. We also found a significant interaction between rearing host and temperature for body size, growth rate and female lifetime fecundity but not larval development time or larval survivorship. The interaction was most apparent for growth rate; the variance in growth rate among hosts increased with increasing temperature. However, the details of host differences differed between our two study populations; the degree to which V. unguiculata was a better host than V. angularis or V. radiata increased at higher temperatures for BF beetles, whereas the degree to which V. unguiculata was the worst host increased at higher temperatures for SI beetles. We also found that the heritabilities of body mass, growth rate and fecundity were similar among rearing hosts and temperatures, and that the cross-temperature genetic correlation was not affected by rearing host, suggesting that genetic architecture is generally stable across rearing conditions. The most important finding of our study is that multiple environmental factors can interact to affect organism growth, but the degree of interaction, and thus the degree of complexity of phenotypic plasticity, varies among traits and between populations.

Revisiting the Holy Grail: using plant functional traits to understand ecological processes.

PubMed

Funk, Jennifer L; Larson, Julie E; Ames, Gregory M; Butterfield, Bradley J; Cavender-Bares, Jeannine; Firn, Jennifer; Laughlin, Daniel C; Sutton-Grier, Ariana E; Williams, Laura; Wright, Justin

2017-05-01

One of ecology's grand challenges is developing general rules to explain and predict highly complex systems. Understanding and predicting ecological processes from species' traits has been considered a 'Holy Grail' in ecology. Plant functional traits are increasingly being used to develop mechanistic models that can predict how ecological communities will respond to abiotic and biotic perturbations and how species will affect ecosystem function and services in a rapidly changing world; however, significant challenges remain. In this review, we highlight recent work and outstanding questions in three areas: (i) selecting relevant traits; (ii) describing intraspecific trait variation and incorporating this variation into models; and (iii) scaling trait data to community- and ecosystem-level processes. Over the past decade, there have been significant advances in the characterization of plant strategies based on traits and trait relationships, and the integration of traits into multivariate indices and models of community and ecosystem function. However, the utility of trait-based approaches in ecology will benefit from efforts that demonstrate how these traits and indices influence organismal, community, and ecosystem processes across vegetation types, which may be achieved through meta-analysis and enhancement of trait databases. Additionally, intraspecific trait variation and species interactions need to be incorporated into predictive models using tools such as Bayesian hierarchical modelling. Finally, existing models linking traits to community and ecosystem processes need to be empirically tested for their applicability to be realized. © 2016 Cambridge Philosophical Society.

Innovation: an emerging focus from cells to societies.

PubMed

Hochberg, Michael E; Marquet, Pablo A; Boyd, Robert; Wagner, Andreas

2017-12-05

Innovations are generally unexpected, often spectacular changes in phenotypes and ecological functions. The contributions to this theme issue are the latest conceptual, theoretical and experimental developments, addressing how ecology, environment, ontogeny and evolution are central to understanding the complexity of the processes underlying innovations. Here, we set the stage by introducing and defining key terms relating to innovation and discuss their relevance to biological, cultural and technological change. Discovering how the generation and transmission of novel biological information, environmental interactions and selective evolutionary processes contribute to innovation as an ecosystem will shed light on how the dominant features across life come to be, generalize to social, cultural and technological evolution, and have applications in the health sciences and sustainability.This article is part of the theme issue 'Process and pattern in innovations from cells to societies'. © 2017 The Author(s).

Innovation: an emerging focus from cells to societies

PubMed Central

Boyd, Robert

2017-01-01

Innovations are generally unexpected, often spectacular changes in phenotypes and ecological functions. The contributions to this theme issue are the latest conceptual, theoretical and experimental developments, addressing how ecology, environment, ontogeny and evolution are central to understanding the complexity of the processes underlying innovations. Here, we set the stage by introducing and defining key terms relating to innovation and discuss their relevance to biological, cultural and technological change. Discovering how the generation and transmission of novel biological information, environmental interactions and selective evolutionary processes contribute to innovation as an ecosystem will shed light on how the dominant features across life come to be, generalize to social, cultural and technological evolution, and have applications in the health sciences and sustainability. This article is part of the theme issue ‘Process and pattern in innovations from cells to societies’. PMID:29061887

Structural complexity, movement bias, and metapopulation extinction risk in dendritic ecological networks

USGS Publications Warehouse

Campbell Grant, Evan H.

2011-01-01

Spatial complexity in metacommunities can be separated into 3 main components: size (i.e., number of habitat patches), spatial arrangement of habitat patches (network topology), and diversity of habitat patch types. Much attention has been paid to lattice-type networks, such as patch-based metapopulations, but interest in understanding ecological networks of alternative geometries is building. Dendritic ecological networks (DENs) include some increasingly threatened ecological systems, such as caves and streams. The restrictive architecture of dendritic ecological networks might have overriding implications for species persistence. I used a modeling approach to investigate how number and spatial arrangement of habitat patches influence metapopulation extinction risk in 2 DENs of different size and topology. Metapopulation persistence was higher in larger networks, but this relationship was mediated by network topology and the dispersal pathways used to navigate the network. Larger networks, especially those with greater topological complexity, generally had lower extinction risk than smaller and less-complex networks, but dispersal bias and magnitude affected the shape of this relationship. Applying these general results to real systems will require empirical data on the movement behavior of organisms and will improve our understanding of the implications of network complexity on population and community patterns and processes.

A Western diet ecological module identified from the 'humanized' mouse microbiota predicts diet in adults and formula feeding in children.

PubMed

Siddharth, Jay; Holway, Nicholas; Parkinson, Scott J

2013-01-01

The interplay between diet and the microbiota has been implicated in the growing frequency of chronic diseases associated with the Western lifestyle. However, the complexity and variability of microbial ecology in humans and preclinical models has hampered identification of the molecular mechanisms underlying the association of the microbiota in this context. We sought to address two key questions. Can the microbial ecology of preclinical models predict human populations? And can we identify underlying principles that surpass the plasticity of microbial ecology in humans? To do this, we focused our study on diet; perhaps the most influential factor determining the composition of the gut microbiota. Beginning with a study in 'humanized' mice we identified an interactive module of 9 genera allied with Western diet intake. This module was applied to a controlled dietary study in humans. The abundance of the Western ecological module correctly predicted the dietary intake of 19/21 top and 21/21 of the bottom quartile samples inclusive of all 5 Western and 'low-fat' diet subjects, respectively. In 98 volunteers the abundance of the Western module correlated appropriately with dietary intake of saturated fatty acids, fat-soluble vitamins and fiber. Furthermore, it correlated with the geographical location and dietary habits of healthy adults from the Western, developing and third world. The module was also coupled to dietary intake in children (and piglets) correlating with formula (vs breast) feeding and associated with a precipitous development of the ecological module in young children. Our study provides a conceptual platform to translate microbial ecology from preclinical models to humans and identifies an ecological network module underlying the association of the gut microbiota with Western dietary habits.

A Western Diet Ecological Module Identified from the ‘Humanized’ Mouse Microbiota Predicts Diet in Adults and Formula Feeding in Children

PubMed Central

Siddharth, Jay; Holway, Nicholas; Parkinson, Scott J.

2013-01-01

The interplay between diet and the microbiota has been implicated in the growing frequency of chronic diseases associated with the Western lifestyle. However, the complexity and variability of microbial ecology in humans and preclinical models has hampered identification of the molecular mechanisms underlying the association of the microbiota in this context. We sought to address two key questions. Can the microbial ecology of preclinical models predict human populations? And can we identify underlying principles that surpass the plasticity of microbial ecology in humans? To do this, we focused our study on diet; perhaps the most influential factor determining the composition of the gut microbiota. Beginning with a study in ‘humanized’ mice we identified an interactive module of 9 genera allied with Western diet intake. This module was applied to a controlled dietary study in humans. The abundance of the Western ecological module correctly predicted the dietary intake of 19/21 top and 21/21 of the bottom quartile samples inclusive of all 5 Western and ‘low-fat’ diet subjects, respectively. In 98 volunteers the abundance of the Western module correlated appropriately with dietary intake of saturated fatty acids, fat-soluble vitamins and fiber. Furthermore, it correlated with the geographical location and dietary habits of healthy adults from the Western, developing and third world. The module was also coupled to dietary intake in children (and piglets) correlating with formula (vs breast) feeding and associated with a precipitous development of the ecological module in young children. Our study provides a conceptual platform to translate microbial ecology from preclinical models to humans and identifies an ecological network module underlying the association of the gut microbiota with Western dietary habits. PMID:24391809

Reviewing molecular adaptations of Lyme borreliosis spirochetes in the context of reproductive fitness in natural transmission cycles.

PubMed

Tsao, Jean I

2009-01-01

Lyme borreliosis (LB) is caused by a group of pathogenic spirochetes - most often Borrelia burgdorferi, B. afzelii, and B. garinii - that are vectored by hard ticks in the Ixodes ricinus-persulcatus complex, which feed on a variety of mammals, birds, and lizards. Although LB is one of the best-studied vector-borne zoonoses, the annual incidence in North America and Europe leads other vector-borne diseases and continues to increase. What factors make the LB system so successful, and how can researchers hope to reduce disease risk - either through vaccinating humans or reducing the risk of contacting infected ticks in nature? Discoveries of molecular interactions involved in the transmission of LB spirochetes have accelerated recently, revealing complex interactions among the spirochete-tick-vertebrate triad. These interactions involve multiple, and often redundant, pathways that reflect the evolution of general and specific mechanisms by which the spirochetes survive and reproduce. Previous reviews have focused on the molecular interactions or population biology of the system. Here molecular interactions among the LB spirochete, its vector, and vertebrate hosts are reviewed in the context of natural maintenance cycles, which represent the ecological and evolutionary contexts that shape these interactions. This holistic system approach may help researchers develop additional testable hypotheses about transmission processes, interpret laboratory results, and guide development of future LB control measures and management.

Bacteria interface interactions in Ecology-on-a-Chip by holographic microscopy and interferometry

NASA Astrophysics Data System (ADS)

Sheng, Jian; White, Andrew; Jalali, Maryam

2017-11-01

To improve our remediation of oil spills into marine system, one must understand the fate of oil under complex physical, chemical and biological environments. It is found that various processes such as wind, wave, turbulence and currents break oil into suspensions of droplets, in which states consumption by microbial further degrade the oil. Our prior studies show that marine bacteria do not adopt biofilm life style at oil-water interface in comparison to those near a solid substrate. On the contrary, Extracellular Polymer Substance of oily microbial aggregates is easily formed around an oil droplet. This highlights complexities of cell oil interactions at a liquid-liquid interface. To investigate these mechanisms at oil water interface quantitative, we have developed a micro-bioassay consisting of continuous microfluidics with a substrate printed with oil droplet array, namely Ecology-on-a-Chip, and an integrated digital holographic microscopy (DHM) and interferometer (DHI). The oil-water interface can be maintained over days (>10 days), suitable for conducting long-term observations. 3D movements of bacteria are tracked by DHM, while the interface morphology are measured by DHI at 10nm. The system is applied to Pseudomonas sp. (PS62) near crude-water interface and Escherichia coli (AW405) at hexadecane-water interface subject to low surface tension. The 3D motility, attachment, detachment and dispersion of cells as well as motility induced interface change are discussed. Funded by Gulf of Mexico Research Initiative (GoMRI).

Land-use change and infectious disease in West Africa

NASA Astrophysics Data System (ADS)

Thomson, M. C.; Ericksen, P. J.; Mohamed, A. Ben; Connor, S. J.

Land-use change has been associated with changes in the dynamics of infectious disease in West Africa. Here we describe the complex interactions of land-use change with three diseases (both vector- and non-vector-borne) of considerable public health significance in this region, namely, malaria and irrigation; epidemic meningitis and land degradation; onchocerciasis and deforestation. We highlight the confounding effect of climate variability, which acts as a driver of both land-use change and human health. We conclude, as have others, that the scale of observation always matters, and complex and dynamic feedbacks among social-ecological systems are not easily teased apart. We suggest that in order to establish the causal chain of interactions between land-use change and human health outcomes two approaches are necessary. The first is to have a thorough understanding of the aetiology of disease and the specific mechanisms by which land-use and climate variability affect the transmission of pathogens. This is achieved by focused, detailed studies encompassing a wide range of potential drivers, which are inevitably small scale and often cover short time periods. The second consists of large-scale studies of statistical associations between transmission indices or health outcomes and environmental variables stratified by known ecological or socio-economic confounders, and sufficient in size to overcome local biases in results. Such research activities need to be designed to inform each other if we are to develop predictive models for monitoring these diseases and to develop integrated programs for human health and sustainable land use.

Cophylogenetic signal is detectable in pollination interactions across ecological scales.

PubMed

Hutchinson, Matthew C; Cagua, Edgar Fernando; Stouffer, Daniel B

2017-10-01

That evolutionary history can influence the way that species interact is a basic tenet of evolutionary ecology. However, when the role of evolution in determining ecological interactions is investigated, focus typically centers on just one side of the interaction. A cophylogenetic signal, the congruence of evolutionary history across both sides of an ecological interaction, extends these previous explorations and provides a more complete picture of how evolutionary patterns influence the way species interact. To date, cophylogenetic signal has most typically been studied in interactions that occur between fine taxonomic clades that show high intimacy. In this study, we took an alternative approach and made an exhaustive assessment of cophylogeny in pollination interactions. To do so, we assessed the strength of cophylogenetic signal at four distinct scales of pollination interaction: (1) across plant-pollinator associations globally, (2) in local pollination communities, (3) within the modular structure of those communities, and (4) in individual modules. We did so using a globally distributed dataset comprised of 54 pollination networks, over 4000 species, and over 12,000 interactions. Within these data, we detected cophylogenetic signal at all four scales. Cophylogenetic signal was found at the level of plant-pollinator interactions on a global scale and in the majority of pollination communities. At the scale defined by the modular structure within those communities, however, we observed a much weaker cophylogenetic signal. Cophylogenetic signal was detectable in a significant proportion of individual modules and most typically when within-module phylogenetic diversity was low. In sum, the detection of cophylogenetic signal in pollination interactions across scales provides a new dimension to the story of how past evolution shapes extant pollinator-angiosperm interactions. © 2017 by the Ecological Society of America.

Mechanisms of biotic resistance across complex life cycles.

PubMed

Rius, Marc; Potter, Elaine E; Aguirre, J David; Stachowicz, John J

2014-01-01

Biotic resistance is the ability of communities to inhibit the establishment, spread or impact of novel species. However, the interactions that underlie biotic resistance depend heavily on the contexts in which species interact. Consequently, studies of biotic resistance that consider single processes, patches, species or life-history stages may provide an incomplete picture of the capacity for communities to resist invasion. Many organisms have multiphasic life cycles, where individuals can occupy distinct niches at different stages of the life history. Generally, studies of biotic resistance focus on interactions within a single life-history stage, and interactions at other life-history stages are overlooked. Here, we demonstrate that different mechanisms of biotic resistance occur across the life history and together limit the invasion success of an introduced marine invertebrate (Ciona intestinalis) in Northern California. We tested the role of interactions (competition and predation) with the resident community in limiting the abundance of Ciona through experiments conducted on fertilization, larval survival, settlement, early postsettlement survival, and the survival of juveniles and adults. Under some circumstances, Ciona became abundant in mid-successional stages and showed more rapid growth rates than a morphologically similar native species, Ascidia ceratodes. However, predators reduced Ciona abundance much more than that of Ascidia at several life stages. Furthermore, Ciona appeared to be a weaker competitor at the adult stage. Early life-history interactions with other sessile species at the fertilization, larval and recruit stages had modest to no effects on Ciona abundance. The presence of biotic resistance mechanisms acting at multiple life stages, and potentially under different conditions, suggests that different components of biotic resistance interact to enhance the resident community's resistance to invasion. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Understanding the biological and environmental implications of nanomaterials

NASA Astrophysics Data System (ADS)

Lin, Sijie

The last two decades have witnessed the discovery, development, and large-scale manufacturing of novel nanomaterials. While nanomaterials bring in exciting and extraordinary properties in all areas of materials, electronics, mechanics, and medicine, they also could generate potential adverse effects in biological systems and in the environment. The currently limited application of nanomaterials in biological and ecological systems results from the insufficient and often controversial data on describing the complex behaviors of nanomaterials in living systems. The purpose of this dissertation intends to fill such a knowledge void with methodologies from the disciplines of biophysics, biology, and materials science and engineering. Chapter 1 of this dissertation provides a comprehensive review on the structures and properties of carbon nanomaterials (CBNMs), metal oxides, and quantum dots (QDs). This chapter also details the state-of-the-art on the biological applications, ecological applications, and toxicity of nanomaterials. With Chapter 1 serving as a background, Chapters 2-5 present my PhD research, an inquiry on the fate of nanomaterials in biological and ecological systems, on the whole organism and cellular levels. Specifically, CBNMs are introduced to rice plant seedlings and the uptake, translocation and generational transfer of fullerene C70 in the plant compartments are imaged and characterized. The interactions between CBNMs and rice plants on the whole organism level are initiated by the binding between CBNMs and natural organic matter (NOM), driven by the transpiration of water from the roots to the leaves of the plants and mediated by both the physiochemical properties of the CBNMs and plant physiology. In Chapter 3, semiconducting nanocrystals quantum dots (QDs) are introduced to green algae Chlamydomonas to probe the interactions of nanomaterials with ecological systems on the cellular level. The adsorption of QDs onto the algal cell wall is quantified by UV-vis spectrophotometry and fitted with the Freundlich isothem. Effects of the adsorption of QDs on the photosynthetic activities of the algae are evaluated using O2 evolution and CO2 depletion assays, and the ecological impact of such adsorption is discussed. To understand the effects of nanomaterials on the cell membrane, nanoparticles (Au, TiO2, and QDs) of different surface charges and chemical compositions are introduced to HT-29 mammalian cells in Chapter 4. The polarization of the cell membrane is investigated using a FLIPR membrane potential kit. The phase of the cell membrane, in the presence of both positively and negatively charged nanoparticles, are examined using laurden, a lipophilic dye that serves as a molecular reporter on the fluidic or gel phase of the host membrane. To address the effects of nanomaterials on biological and ecological systems within the same context, Chapter 5 offers a first parallel comparison between mammalian and plant cell responses to nanomaterials. This study is conducted using a plant cell viability assay, complimented by bright field, fluorescence, and electron microscopy imaging. Discussions of this study are presented based on the hydrophobicity and solubility of C60(OH) 20 and of supramolecular complex C70-NOM, hydrophobicity and porous structure of the plant Allium cepa cell wall, and the amphiphilic structure and endocytosis of the plasma cell membrane of both Allium cepa and HT-29 cells. Chapter 6 summarizes and rationalizes results obtained from the entire dissertation research. Future work inspired by this research is presented at the end of the chapter. Specifically, this dissertation is structured to embody the following essential and complementary chapters: (1) Chapter 1: Literature review (2) Chapter 2: Nano-Eco interactions at the whole organism level; (3) Chapter 3: Nano-Eco interactions at the cellular level; (4) Chapter 4: Nano-Bio interactions at the cellular level; (5) Chapter 5: Parallel comparison of Nano-Eco and Nano-Bio interactions at the cellular level. (6) Chapter 6: Conclusions and future work. The overarching goal of this research is to advance our understanding on the fate of nanomaterials in biological and ecological systems. Knowledge obtained from this dissertation is expected to benefit future research on the implications and applications of engineered nanomaterials.

The effect of phenotypic traits and external cues on natal dispersal movements.

PubMed

Delgado, María del Mar; Penteriani, Vincenzo; Revilla, Eloy; Nams, Vilis O

2010-05-01

1. Natal dispersal has the potential to affect most ecological and evolutionary processes. However, despite its importance, this complex ecological process still represents a significant gap in our understanding of animal ecology due to both the lack of empirical data and the intrinsic complexity of dispersal dynamics. 2. By studying natal dispersal of 74 radiotagged juvenile eagle owls Bubo bubo (Linnaeus), in both the wandering and the settlement phases, we empirically addressed the complex interactions by which individual phenotypic traits and external cues jointly shape individual heterogeneity through the different phases of dispersal, both at nightly and weekly temporal scales. 3. Owls in poorer physical conditions travelled shorter total distances during the wandering phase, describing straighter paths and moving slower, especially when crossing heterogeneous habitats. In general, the owls in worse condition started dispersal later and took longer times to find further settlement areas. Net distances were also sex biased, with females settling at further distances. Dispersing individuals did not seem to explore wandering and settlement areas by using a search image of their natal surroundings. Eagle owls showed a heterogeneous pattern of patch occupancy, where few patches were highly visited by different owls whereas the majority were visited by just one individual. During dispersal, the routes followed by owls were an intermediate solution between optimized and randomized ones. Finally, dispersal direction had a marked directionality, largely influenced by dominant winds. These results suggest an asymmetric and anisotropic dispersal pattern, where not only the number of patches but also their functions can affect population viability. 4. The combination of the information coming from the relationships among a large set of factors acting and integrating at different spatial and temporal scales, under the perspective of heterogeneous life histories, are a fruitful ground for future understanding of natal dispersal.

Evolutionary fields can explain patterns of high-dimensional complexity in ecology

NASA Astrophysics Data System (ADS)

Wilsenach, James; Landi, Pietro; Hui, Cang

2017-04-01

One of the properties that make ecological systems so unique is the range of complex behavioral patterns that can be exhibited by even the simplest communities with only a few species. Much of this complexity is commonly attributed to stochastic factors that have very high-degrees of freedom. Orthodox study of the evolution of these simple networks has generally been limited in its ability to explain complexity, since it restricts evolutionary adaptation to an inertia-free process with few degrees of freedom in which only gradual, moderately complex behaviors are possible. We propose a model inspired by particle-mediated field phenomena in classical physics in combination with fundamental concepts in adaptation, which suggests that small but high-dimensional chaotic dynamics near to the adaptive trait optimum could help explain complex properties shared by most ecological datasets, such as aperiodicity and pink, fractal noise spectra. By examining a simple predator-prey model and appealing to real ecological data, we show that this type of complexity could be easily confused for or confounded by stochasticity, especially when spurred on or amplified by stochastic factors that share variational and spectral properties with the underlying dynamics.

Volatile affairs in microbial interactions

PubMed Central

Schmidt, Ruth; Cordovez, Viviane; de Boer, Wietse; Raaijmakers, Jos; Garbeva, Paolina

2015-01-01

Microorganisms are important factors in shaping our environment. One key characteristic that has been neglected for a long time is the ability of microorganisms to release chemically diverse volatile compounds. At present, it is clear that the blend of volatiles released by microorganisms can be very complex and often includes many unknown compounds for which the chemical structures remain to be elucidated. The biggest challenge now is to unravel the biological and ecological functions of these microbial volatiles. There is increasing evidence that microbial volatiles can act as infochemicals in interactions among microbes and between microbes and their eukaryotic hosts. Here, we review and discuss recent advances in understanding the natural roles of volatiles in microbe–microbe interactions. Specific emphasis will be given to the antimicrobial activities of microbial volatiles and their effects on bacterial quorum sensing, motility, gene expression and antibiotic resistance. PMID:26023873

Will it rise or will it fall? Managing the complex effects of urbanization on base flow

USGS Publications Warehouse

Bhaskar, Aditi; Beesley, Leah; Burns, Matthew J.; Fletcher, T. D.; Hamel, Perrine; Oldham, Carolyn; Roy, Allison

2016-01-01

Sustaining natural levels of base flow is critical to maintaining ecological function as stream catchments are urbanized. Research shows a variable response of stream base flow to urbanization, with base flow or water tables rising in some locations, falling in others, or elsewhere remaining constant. The variable baseflow response is due to the array of natural (e.g., physiographic setting and climate) and anthropogenic (e.g., urban development and infrastructure) factors that influence hydrology. Perhaps as a consequence of this complexity, few simple tools exist to assist managers to predict baseflow change in their local urban area. This paper addresses this management need by presenting a decision support tool. The tool considers the natural vulnerability of the landscape, together with aspects of urban development in predicting the likelihood and direction of baseflow change. Where the tool identifies a likely increase or decrease it guides managers toward strategies that can reduce or increase groundwater recharge, respectively. Where the tool finds an equivocal result, it suggests a detailed water balance be performed. The decision support tool is embedded within an adaptive-management framework that encourages managers to define their ecological objectives, assess the vulnerability of their ecological objectives to changes in water table height, and monitor baseflow responses to urbanization. We trial our framework using two very different case studies: Perth, Western Australia, and Baltimore, Maryland, USA. Together, these studies show how pre-development water table height, climate and geology together with aspects of urban infrastructure (e.g., stormwater practices, leaky pipes) interact such that urbanization has overall led to rising base flow (Perth) and falling base flow (Baltimore). Greater consideration of subsurface components of the water cycle will help to protect and restore the ecology of urban freshwaters.

Equation-free modeling unravels the behavior of complex ecological systems

USGS Publications Warehouse

DeAngelis, Donald L.; Yurek, Simeon

2015-01-01

Ye et al. (1) address a critical problem confronting the management of natural ecosystems: How can we make forecasts of possible future changes in populations to help guide management actions? This problem is especially acute for marine and anadromous fisheries, where the large interannual fluctuations of populations, arising from complex nonlinear interactions among species and with varying environmental factors, have defied prediction over even short time scales. The empirical dynamic modeling (EDM) described in Ye et al.’s report, the latest in a series of papers by Sugihara and his colleagues, offers a promising quantitative approach to building models using time series to successfully project dynamics into the future. With the term “equation-free” in the article title, Ye et al. (1) are suggesting broader implications of their approach, considering the centrality of equations in modern science. From the 1700s on, nature has been increasingly described by mathematical equations, with differential or difference equations forming the basic framework for describing dynamics. The use of mathematical equations for ecological systems came much later, pioneered by Lotka and Volterra, who showed that population cycles might be described in terms of simple coupled nonlinear differential equations. It took decades for Lotka–Volterra-type models to become established, but the development of appropriate differential equations is now routine in modeling ecological dynamics. There is no question that the injection of mathematical equations, by forcing “clarity and precision into conjecture” (2), has led to increased understanding of population and community dynamics. As in science in general, in ecology equations are a key method of communication and of framing hypotheses. These equations serve as compact representations of an enormous amount of empirical data and can be analyzed by the powerful methods of mathematics.

The roles of amensalistic and commensalistic interactions in large ecological network stability

PubMed Central

Mougi, Akihiko

2016-01-01

Ecological communities comprise diverse species and their interactions. Notably, ecological and evolutionary studies have revealed that reciprocal interactions such as predator–prey, competition, and mutualism, are key drivers of community dynamics. However, there is an argument that many species interactions are asymmetric, where one species unilaterally affects another species (amensalism or commensalism). This raises the unanswered question of what is the role of unilateral interactions in community dynamics. Here I use a theoretical approach to demonstrate that unilateral interactions greatly enhance community stability. The results suggested that amensalism and commensalism were more stabilizing than symmetrical interactions, such as competition and mutualism, but they were less stabilizing than an asymmetric antagonistic interaction. A mix of unilateral interactions increased stability. Furthermore, in communities with all interaction types, unilateral interactions tended to increase stability. This study suggests that unilateral interactions play a major role in maintaining communities, underlining the need to further investigate their roles in ecosystem dynamics. PMID:27406267

Interactions between spatially explicit conservation and management measures: implications for the governance of marine protected areas.

PubMed

Cárcamo, P Francisco; Gaymer, Carlos F

2013-12-01

Marine protected areas are not established in an institutional and governance vacuum and managers should pay attention to the wider social-ecological system in which they are immersed. This article examines Islas Choros-Damas Marine Reserve, a small marine protected area located in a highly productive and biologically diverse coastal marine ecosystem in northern Chile, and the interactions between human, institutional, and ecological dimensions beyond those existing within its boundaries. Through documents analysis, surveys, and interviews, we described marine reserve implementation (governing system) and the social and natural ecosystem-to-be-governed. We analyzed the interactions and the connections between the marine reserve and other spatially explicit conservation and/or management measures existing in the area and influencing management outcomes and governance. A top-down approach with poor stakeholder involvement characterized the implementation process. The marine reserve is highly connected with other spatially explicit measures and with a wider social-ecological system through various ecological processes and socio-economic interactions. Current institutional interactions with positive effects on the management and governance are scarce, although several potential interactions may be developed. For the study area, any management action must recognize interferences from outside conditions and consider some of them (e.g., ecotourism management) as cross-cutting actions for the entire social-ecological system. We consider that institutional interactions and the development of social networks are opportunities to any collective effort aiming to improve governance of Islas Choros-Damas marine reserve. Communication of connections and interactions between marine protected areas and the wider social-ecological system (as described in this study) is proposed as a strategy to improve stakeholder participation in Chilean marine protected areas.

Interactions Between Spatially Explicit Conservation and Management Measures: Implications for the Governance of Marine Protected Areas

NASA Astrophysics Data System (ADS)

Cárcamo, P. Francisco; Gaymer, Carlos F.

2013-12-01

Marine protected areas are not established in an institutional and governance vacuum and managers should pay attention to the wider social-ecological system in which they are immersed. This article examines Islas Choros-Damas Marine Reserve, a small marine protected area located in a highly productive and biologically diverse coastal marine ecosystem in northern Chile, and the interactions between human, institutional, and ecological dimensions beyond those existing within its boundaries. Through documents analysis, surveys, and interviews, we described marine reserve implementation (governing system) and the social and natural ecosystem-to-be-governed. We analyzed the interactions and the connections between the marine reserve and other spatially explicit conservation and/or management measures existing in the area and influencing management outcomes and governance. A top-down approach with poor stakeholder involvement characterized the implementation process. The marine reserve is highly connected with other spatially explicit measures and with a wider social-ecological system through various ecological processes and socio-economic interactions. Current institutional interactions with positive effects on the management and governance are scarce, although several potential interactions may be developed. For the study area, any management action must recognize interferences from outside conditions and consider some of them (e.g., ecotourism management) as cross-cutting actions for the entire social-ecological system. We consider that institutional interactions and the development of social networks are opportunities to any collective effort aiming to improve governance of Islas Choros-Damas marine reserve. Communication of connections and interactions between marine protected areas and the wider social-ecological system (as described in this study) is proposed as a strategy to improve stakeholder participation in Chilean marine protected areas.

A file study of refugee children referred to specialized mental health care: from an individual diagnostic to an ecological perspective.

PubMed

Villanueva O'Driscoll, Julia; Serneels, Geertrui; Imeraj, Lindita

2017-11-01

The past years have been characterized by a large refugee crisis across the globe. The exposure to preflight, flight, and resettlement stressors puts refugee children and their families at risk of developing emotional and behavioral disorders. A unique Western-based approach of mental health problems seems to be insufficient to address the complexity of interactions between individual vulnerabilities and more ecological surrounding systems. We looked into (1) the reasons for referral; and (2) the process diagnostic outcomes after ethnopsychiatric and psychological assessment. We conducted a thematic content analysis on 93 files of refugee children. The findings suggest that mental health care professionals need to hold into account the multiplicity and intertwining of ongoing challenges to the well-being of refugee children. The integration of a Western-based psychiatric assessment with a more ecologically based view can lead to a more culturally sensitive approach in refugee children and their families. This way, both under- and overdiagnosis of psychiatric disorders could be avoided to further optimalise mental health care in this population.

Validating spatial structure in canopy water content using geostatistics

NASA Technical Reports Server (NTRS)

Sanderson, E. W.; Zhang, M. H.; Ustin, S. L.; Rejmankova, E.; Haxo, R. S.

1995-01-01

Heterogeneity in ecological phenomena are scale dependent and affect the hierarchical structure of image data. AVIRIS pixels average reflectance produced by complex absorption and scattering interactions between biogeochemical composition, canopy architecture, view and illumination angles, species distributions, and plant cover as well as other factors. These scales affect validation of pixel reflectance, typically performed by relating pixel spectra to ground measurements acquired at scales of 1m(exp 2) or less (e.g., field spectra, foilage and soil samples, etc.). As image analysis becomes more sophisticated, such as those for detection of canopy chemistry, better validation becomes a critical problem. This paper presents a methodology for bridging between point measurements and pixels using geostatistics. Geostatistics have been extensively used in geological or hydrogeolocial studies but have received little application in ecological studies. The key criteria for kriging estimation is that the phenomena varies in space and that an underlying controlling process produces spatial correlation between the measured data points. Ecological variation meets this requirement because communities vary along environmental gradients like soil moisture, nutrient availability, or topography.

Microbial disease and the coral holobiont

USGS Publications Warehouse

Bourne, David G.; Garren, Melissa; Work, Thierry M.; Rosenberg, Eugene; Smith, Garriet W.; Harvell, C. Drew

2009-01-01

Tropical coral reefs harbour a reservoir of enormous biodiversity that is increasingly threatened by direct human activities and indirect global climate shifts. Emerging coral diseases are one serious threat implicated in extensive reef deterioration through disruption of the integrity of the coral holobiont – a complex symbiosis between the coral animal, endobiotic alga and an array of microorganisms. In this article, we review our current understanding of the role of microorganisms in coral health and disease, and highlight the pressing interdisciplinary research priorities required to elucidate the mechanisms of disease. We advocate an approach that applies knowledge gained from experiences in human and veterinary medicine, integrated into multidisciplinary studies that investigate the interactions between host, agent and environment of a given coral disease. These approaches include robust and precise disease diagnosis, standardised ecological methods and application of rapidly developing DNA, RNA and protein technologies, alongside established histological, microbial ecology and ecological expertise. Such approaches will allow a better understanding of the causes of coral mortality and coral reef declines and help assess potential management options to mitigate their effects in the longer term.

Taking peer victimization research to the next level: complex interactions among genes, teacher attitudes/behaviors, peer ecologies, & classroom characteristics.

PubMed

Espelage, Dorothy L

2015-01-01

This commentary reviews research findings of the five papers in the special entitled "School-related Factors in the Development of Bullying Perpetration and Victimization", which represent critical areas that are often overlooked in the literature. First, one paper points to the complex interaction between a genetic disposition for aggression and classroom norms toward aggression. Second, an intervention paper unpacks the underlying mechanisms of an efficacious school-wide bully prevention program by opening the "black box" and testing for mediators. Third, the remaining studies employ a wide range of rigorous designs to identify how teachers' attitudes, behaviors, and classroom practices play a critical role in the prevalence of victimization and bullying in the classroom. Further, teachers' attitudes and behaviors are shown to be predictive of youth's willingness to intervene to assist a peer who is being victimized. Results are situated in what is known about bullying prevention, and how the findings from these studies could maximize the sensitivity of future prevention efforts.

Teaching Ecological Principles as a Basis for Understanding Environmental Issues.

ERIC Educational Resources Information Center

Webb, Paul; Boltt, Gill

1989-01-01

Using case study data, determines high school pupils' and university students' (n=162) ability to predict possible outcomes of interactions between ecological populations . Results indicate the majority of respondents could predict interactive outcomes within a simple food web but not when the interaction involved multiple routes. (five…

Ecological consequences of interactions between ants and honeydew-producing insects

PubMed Central

Styrsky, John D; Eubanks, Micky D

2006-01-01

Interactions between ants and honeydew-producing hemipteran insects are abundant and widespread in arthropod food webs, yet their ecological consequences are very poorly known. Ant–hemipteran interactions have potentially broad ecological effects, because the presence of honeydew-producing hemipterans dramatically alters the abundance and predatory behaviour of ants on plants. We review several studies that investigate the consequences of ant–hemipteran interactions as ‘keystone interactions’ on arthropod communities and their host plants. Ant–hemipteran interactions have mostly negative effects on the local abundance and species richness of several guilds of herbivores and predators. In contrast, out of the 30 studies that document the effects of ant–hemipteran interactions on plants, the majority (73%) shows that plants actually benefit indirectly from these interactions. In these studies, increased predation or harassment of other, more damaging, herbivores by hemipteran-tending ants resulted in decreased plant damage and/or increased plant growth and reproduction. The ecological consequences of mutualistic interactions between honeydew-producing hemipterans and invasive ants relative to native ants have rarely been studied, but they may be of particular importance owing to the greater abundance, aggressiveness and extreme omnivory of invasive ants. We argue that ant–hemipteran interactions are largely overlooked and underappreciated interspecific interactions that have strong and pervasive effects on the communities in which they are embedded. PMID:17148245

A factorial assessment of the sensitivity of the BATS land-surface parameterization scheme. [BATS (Biosphere-Atmosphere Transfer Scheme)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henderson-Sellers, A.

Land-surface schemes developed for incorporation into global climate models include parameterizations that are not yet fully validated and depend upon the specification of a large (20-50) number of ecological and soil parameters, the values of which are not yet well known. There are two methods of investigating the sensitivity of a land-surface scheme to prescribed values: simple one-at-a-time changes or factorial experiments. Factorial experiments offer information about interactions between parameters and are thus a more powerful tool. Here the results of a suite of factorial experiments are reported. These are designed (i) to illustrate the usefulness of this methodology andmore » (ii) to identify factors important to the performance of complex land-surface schemes. The Biosphere-Atmosphere Transfer Scheme (BATS) is used and its sensitivity is considered (a) to prescribed ecological and soil parameters and (b) to atmospheric forcing used in the off-line tests undertaken. Results indicate that the most important atmospheric forcings are mean monthly temperature and the interaction between mean monthly temperature and total monthly precipitation, although fractional cloudiness and other parameters are also important. The most important ecological parameters are vegetation roughness length, soil porosity, and a factor describing the sensitivity of the stomatal resistance of vegetation to the amount of photosynthetically active solar radiation and, to a lesser extent, soil and vegetation albedos. Two-factor interactions including vegetation roughness length are more important than many of the 23 specified single factors. The results of factorial sensitivity experiments such as these could form the basis for intercomparison of land-surface parameterization schemes and for field experiments and satellite-based observation programs aimed at improving evaluation of important parameters.« less

Theories of Simplification and Scaling of Spatially Distributed Processes. Chapter 12

NASA Technical Reports Server (NTRS)

Levin, Simon A.; Pacala, Stephen W.

1997-01-01

The problem of scaling is at the heart of ecological theory, the essence of understanding and of the development of a predictive capability. The description of any system depends on the spatial, temporal, and organizational perspective chosen; hence it is essential to understand not only how patterns and dynamics vary with scale, but also how patterns at one scale are manifestations of processes operating at other scales. Evolution has shaped the characteristics of species in ways that result in scale displacement: Each species experiences the environment at its own unique set of spatial and temporal scales and interfaces the biota through unique assemblages of phenotypes. In this way, coexistence becomes possible, and biodiversity is enhanced. By averaging over space, time, and biological interactions, a genotype filters variation at fine scales and selects the arena in which it will face the vicissitudes of nature. Variation at finer scales is then noise, of minor importance to the survival and dynamics of the species, and consequently of minor importance in any attempt at description. In attempting to model ecological interactions in space, contributors throughout this book have struggled with a trade-off between simplification and "realistic" complexity and detail. Although the challenge of simplification is widely recognized in ecology, less appreciated is the intertwining of scaling questions and scaling laws with the process of simplification. In the context of this chapter simplification will in general mean the use of spatial or ensemble means and low-order moments to capture more detailed interactions by integrating over given areas. In this way, one can derive descriptions of the system at different spatial scales, which provides the essentials for the extraction of scaling laws by examination of how system properties vary with scale.

Deciphering microbial interactions in synthetic human gut microbiome communities.

PubMed

Venturelli, Ophelia S; Carr, Alex C; Fisher, Garth; Hsu, Ryan H; Lau, Rebecca; Bowen, Benjamin P; Hromada, Susan; Northen, Trent; Arkin, Adam P

2018-06-21

The ecological forces that govern the assembly and stability of the human gut microbiota remain unresolved. We developed a generalizable model-guided framework to predict higher-dimensional consortia from time-resolved measurements of lower-order assemblages. This method was employed to decipher microbial interactions in a diverse human gut microbiome synthetic community. We show that pairwise interactions are major drivers of multi-species community dynamics, as opposed to higher-order interactions. The inferred ecological network exhibits a high proportion of negative and frequent positive interactions. Ecological drivers and responsive recipient species were discovered in the network. Our model demonstrated that a prevalent positive and negative interaction topology enables robust coexistence by implementing a negative feedback loop that balances disparities in monospecies fitness levels. We show that negative interactions could generate history-dependent responses of initial species proportions that frequently do not originate from bistability. Measurements of extracellular metabolites illuminated the metabolic capabilities of monospecies and potential molecular basis of microbial interactions. In sum, these methods defined the ecological roles of major human-associated intestinal species and illuminated design principles of microbial communities. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

Toward a social-ecological theory of forest macrosystems for improved ecosystem management

USGS Publications Warehouse

Kleindl, William J.; Stoy, Paul C.; Binford, Michael W.; Desai, Ankur R.; Dietze, Michael C.; Schultz, Courtney A.; Starr, Gregory; Staudhammer, Christina; Wood, David J. A.

2018-01-01

The implications of cumulative land-use decisions and shifting climate on forests, require us to integrate our understanding of ecosystems, markets, policy, and resource management into a social-ecological system. Humans play a central role in macrosystem dynamics, which complicates ecological theories that do not explicitly include human interactions. These dynamics also impact ecological services and related markets, which challenges economic theory. Here, we use two forest macroscale management initiatives to develop a theoretical understanding of how management interacts with ecological functions and services at these scales and how the multiple large-scale management goals work either in consort or conflict with other forest functions and services. We suggest that calling upon theories developed for organismal ecology, ecosystem ecology, and ecological economics adds to our understanding of social-ecological macrosystems. To initiate progress, we propose future research questions to add rigor to macrosystem-scale studies: (1) What are the ecosystem functions that operate at macroscales, their necessary structural components, and how do we observe them? (2) How do systems at one scale respond if altered at another scale? (3) How do we both effectively measure these components and interactions, and communicate that information in a meaningful manner for policy and management across different scales?

Soil and water related forest ecosystem services and resilience of social ecological system in the Central Highlands of Ethiopia

NASA Astrophysics Data System (ADS)

Tekalign, Meron; Muys, Bart; Nyssen, Jan; Poesen, Jean

2014-05-01

In the central highlands of Ethiopia, deforestation and forest degradation are occurring and accelerating during the last century. The high population pressure is the most repeatedly mentioned reason. However, in the past 30 years researchers agreed that the absence of institutions, which could define the access rights to particular forest resources, is another underlying cause of forest depletion and loss. Changing forest areas into different land use types is affecting the biodiversity, which is manifested through not proper functioning of ecosystem services. Menagesha Suba forest, the focus of this study has been explored from various perspectives. However the social dimension and its interaction with the ecology have been addressed rarely. This research uses a combined theoretical framework of Ecosystem Services and that of Resilience thinking for understanding the complex social-ecological interactions in the forest and its influence on ecosystem services. For understanding the history and extent of land use land cover changes, in-depth literature review and a GIS and remote sensing analysis will be made. The effect of forest conversion into plantation and agricultural lands on soil and above ground carbon sequestration, fuel wood and timber products delivery will be analyzed with the accounting of the services on five land use types. The four ecosystem services to be considered are Supporting, Provisioning, Regulating, and Cultural services as set by the Millennium Ecosystem Assessment. A resilience based participatory framework approach will be used to analyze how the social and ecological systems responded towards the drivers of change that occurred in the past. The framework also will be applied to predict future uncertainties. Finally this study will focus on the possible interventions that could contribute to the sustainable management and conservation of the forest. An ecosystem services trade-off analysis and an environmental valuation of the water regulation and soil erosion control services will be made to propose solutions for increasing the social-ecological system resilience of Menagesha Suba forest.

Attacking cancer dormacy using game theory

NASA Astrophysics Data System (ADS)

Austin, Robert

Here is the problem: Cancer kills primarily by re-emergence from a period of dormancy after initial treatment. The presence of driver mutations and subsequent clonal expansion by Darwinian evolution does not explain dormancy and re-emergence of cancer from a community of cancer and host cells (including stromal and immune cells), nor does it explain our inability to predict the emergence of metastasis, by far the real killer in cancer. Dormancy appears to be a slow-driven, multi-cell interaction-dominated, threshold system with a poor prognosis once the cancer emerges from dormancy. The mission here is to try and model the phenomena of dormancy using game theory ideas, and in an in vitro complex ecology designed to emulate the true complexity of an in vivo tumor.

Ecosystems and the Biosphere as Complex Adaptive Systems

NASA Technical Reports Server (NTRS)

Levin, Simon A.

1998-01-01

Ecosystems are prototypical examples of complex adaptive systems, in which patterns at higher levels emerge from localized interactions and selection processes acting at lower levels. An essential aspect of such systems is nonlinearity, leading to historical dependency and multiple possible outcomes of dynamics. Given this, it is essential to determine the degree to which system features are determined by environmental conditions, and the degree to which they are the result of self-organization. Furthermore, given the multiple levels at which dynamics become apparent and at which selection can act, central issues relate to how evolution shapes ecosystems properties, and whether ecosystems become buffered to changes (more resilient) over their ecological and evolutionary development or proceed to critical states and the edge of chaos.

Primate dental ecology: How teeth respond to the environment.

PubMed

Cuozzo, Frank P; Ungar, Peter S; Sauther, Michelle L

2012-06-01

Teeth are central for the study of ecology, as teeth are at the direct interface between an organism and its environment. Recent years have witnessed a rapid growth in the use of teeth to understand a broad range of topics in living and fossil primate biology. This in part reflects new techniques for assessing ways in which teeth respond to, and interact with, an organism's environment. Long-term studies of wild primate populations that integrate dental analyses have also provided a new context for understanding primate interactions with their environments. These new techniques and long-term field studies have allowed the development of a new perspective-dental ecology. We define dental ecology as the broad study of how teeth respond to, or interact with, the environment. This includes identifying patterns of dental pathology and tooth use-wear, as they reflect feeding ecology, behavior, and habitat variation, including areas impacted by anthropogenic disturbance, and how dental development can reflect environmental change and/or stress. The dental ecology approach, built on collaboration between dental experts and ecologists, holds the potential to provide an important theoretical and practical framework for inferring ecology and behavior of fossil forms, for assessing environmental change in living populations, and for understanding ways in which habitat impacts primate growth and development. This symposium issue brings together experts on dental morphology, growth and development, tooth wear and health, primate ecology, and paleontology, to explore the broad application of dental ecology to questions of how living and fossil primates interact with their environments. Copyright © 2012 Wiley Periodicals, Inc.

Observations on the interaction of nanomaterials with bacteria

NASA Astrophysics Data System (ADS)

Raja, P. M.; Ajayan, P. M.; Nalamasu, O.; Sharma, A.

2006-05-01

Large scale commercial manufacturing of nanomaterials raises the important issue of their environmental fate. With increased production (estimated to be in million gallon range) the nanomaterial interactions with environmental microbial ecology would be significant. However, there are scant studies that have addressed this concern. It is therefore essential to experimentally determine some fundamental parameters to ascertain any environmental stresses related to microbiological interactions of nanomaterials. There are concerns that such an interaction may be similar to the biogeochemical interactions of asbestos fibers, which continues to be an alarming environmental issue. Carbon nanotubes (CNTs) are newly emerging nanomaterials, with a wide range of potential electronic and medical applications. Though CNTs are dimensionally similar to the mineral fibers, they differ morphologically, and can possess different surface chemistries, capable of complex and varied biological interactions within the environment. In this study, we present experimental data that show discernible effects on microbial morphology, biofilm formation, substrate consumption rates and growth of Escherichia coli in the presence of carbon nanotubes with the aim of developing a fundamental understanding of the environmental implications of CNT-microbial interactions.

High refuge availability on coral reefs increases the vulnerability of reef-associated predators to overexploitation.

PubMed

Rogers, Alice; Blanchard, Julia L; Newman, Steven P; Dryden, Charlie S; Mumby, Peter J

2018-02-01

Refuge availability and fishing alter predator-prey interactions on coral reefs, but our understanding of how they interact to drive food web dynamics, community structure and vulnerability of different trophic groups is unclear. Here, we apply a size-based ecosystem model of coral reefs, parameterized with empirical measures of structural complexity, to predict fish biomass, productivity and community structure in reef ecosystems under a broad range of refuge availability and fishing regimes. In unfished ecosystems, the expected positive correlation between reef structural complexity and biomass emerges, but a non-linear effect of predation refuges is observed for the productivity of predatory fish. Reefs with intermediate complexity have the highest predator productivity, but when refuge availability is high and prey are less available, predator growth rates decrease, with significant implications for fisheries. Specifically, as fishing intensity increases, predators in habitats with high refuge availability exhibit vulnerability to over-exploitation, resulting in communities dominated by herbivores. Our study reveals mechanisms for threshold dynamics in predators living in complex habitats and elucidates how predators can be food-limited when most of their prey are able to hide. We also highlight the importance of nutrient recycling via the detrital pathway, to support high predator biomasses on coral reefs. © 2018 by the Ecological Society of America.

System Dynamics Modeling for Public Health: Background and Opportunities

PubMed Central

Homer, Jack B.; Hirsch, Gary B.

2006-01-01

The systems modeling methodology of system dynamics is well suited to address the dynamic complexity that characterizes many public health issues. The system dynamics approach involves the development of computer simulation models that portray processes of accumulation and feedback and that may be tested systematically to find effective policies for overcoming policy resistance. System dynamics modeling of chronic disease prevention should seek to incorporate all the basic elements of a modern ecological approach, including disease outcomes, health and risk behaviors, environmental factors, and health-related resources and delivery systems. System dynamics shows promise as a means of modeling multiple interacting diseases and risks, the interaction of delivery systems and diseased populations, and matters of national and state policy. PMID:16449591

Environmental Microbial Community Proteomics: Status, Challenges and Perspectives.

PubMed

Wang, Da-Zhi; Kong, Ling-Fen; Li, Yuan-Yuan; Xie, Zhang-Xian

2016-08-05

Microbial community proteomics, also termed metaproteomics, is an emerging field within the area of microbiology, which studies the entire protein complement recovered directly from a complex environmental microbial community at a given point in time. Although it is still in its infancy, microbial community proteomics has shown its powerful potential in exploring microbial diversity, metabolic potential, ecological function and microbe-environment interactions. In this paper, we review recent advances achieved in microbial community proteomics conducted in diverse environments, such as marine and freshwater, sediment and soil, activated sludge, acid mine drainage biofilms and symbiotic communities. The challenges facing microbial community proteomics are also discussed, and we believe that microbial community proteomics will greatly enhance our understanding of the microbial world and its interactions with the environment.

Applying evolutionary concepts to wildlife disease ecology and management

PubMed Central

Vander Wal, Eric; Garant, Dany; Calmé, Sophie; Chapman, Colin A; Festa-Bianchet, Marco; Millien, Virginie; Rioux-Paquette, Sébastien; Pelletier, Fanie

2014-01-01

Existing and emerging infectious diseases are among the most pressing global threats to biodiversity, food safety and human health. The complex interplay between host, pathogen and environment creates a challenge for conserving species, communities and ecosystem functions, while mediating the many known ecological and socio-economic negative effects of disease. Despite the clear ecological and evolutionary contexts of host–pathogen dynamics, approaches to managing wildlife disease remain predominantly reactionary, focusing on surveillance and some attempts at eradication. A few exceptional studies have heeded recent calls for better integration of ecological concepts in the study and management of wildlife disease; however, evolutionary concepts remain underused. Applied evolution consists of four principles: evolutionary history, genetic and phenotypic variation, selection and eco-evolutionary dynamics. In this article, we first update a classical framework for understanding wildlife disease to integrate better these principles. Within this framework, we explore the evolutionary implications of environment–disease interactions. Subsequently, we synthesize areas where applied evolution can be employed in wildlife disease management. Finally, we discuss some future directions and challenges. Here, we underscore that despite some evolutionary principles currently playing an important role in our understanding of disease in wild animals, considerable opportunities remain for fostering the practice of evolutionarily enlightened wildlife disease management. PMID:25469163

Divergence of developmental trajectories is triggered interactively by early social and ecological experience in a cooperative breeder

PubMed Central

Bohn, Lena; Oberhummer, Evelyne

2017-01-01

Cooperative breeders feature the highest level of social complexity among vertebrates. Environmental constraints foster the evolution of this form of social organization, selecting for both well-developed social and ecological competences. Cooperative breeders pursue one of two alternative social trajectories: delaying reproduction to care for the offspring of dominant breeders or dispersing early to breed independently. It is yet unclear which ecological and social triggers determine the choice between these alternatives and whether diverging developmental trajectories exist in cooperative vertebrates predisposing them to dispersal or philopatry. Here we experimentally reared juveniles of cooperatively breeding cichlid fish by varying the social environment and simulated predation threat in a two-by-two factorial long-term experiment. First, we show that individuals develop specialized behavioral competences, originating already in the early postnatal phase. Second, these specializations predisposed individuals to pursue different developmental trajectories and either to disperse early or to extend philopatry in adulthood. Thus, our results contrast with the proposition that social specializations in early ontogeny should be restricted to eusocial species. Importantly, social and ecological triggers were both required for the generation of divergent life histories. Our results thus confirm recent predictions from theoretical models that organisms should combine relevant information from different environmental cues to develop integrated phenotypes. PMID:29078289

Modulators of mercury risk to wildlife and humans in the context of rapid global change

USGS Publications Warehouse

Eagles-Smith, Collin A.; Silbergeld, Ellen K.; Basu, Niladri; Bustamante, Paco; Diaz-Barriga, Fernando; Hopkins, William A.; Kidd, Karen A.; Nyland, Jennifer F.

2018-01-01

Environmental mercury (Hg) contamination is an urgent global health threat. The complexity of Hg in the environment can hinder accurate determination of ecological and human health risks, particularly within the context of the rapid global changes that are altering many ecological processes, socioeconomic patterns, and other factors like infectious disease incidence, which can affect Hg exposures and health outcomes. However, the success of global Hg-reduction efforts depends on accurate assessments of their effectiveness in reducing health risks. In this paper, we examine the role that key extrinsic and intrinsic drivers play on several aspects of Hg risk to humans and organisms in the environment. We do so within three key domains of ecological and human health risk. First, we examine how extrinsic global change drivers influence pathways of Hg bioaccumulation and biomagnification through food webs. Next, we describe how extrinsic socioeconomic drivers at a global scale, and intrinsic individual-level drivers, influence human Hg exposure. Finally, we address how the adverse health effects of Hg in humans and wildlife are modulated by a range of extrinsic and intrinsic drivers within the context of rapid global change. Incorporating components of these three domains into research and monitoring will facilitate a more holistic understanding of how ecological and societal drivers interact to influence Hg health risks.

Applying evolutionary concepts to wildlife disease ecology and management.

PubMed

Vander Wal, Eric; Garant, Dany; Calmé, Sophie; Chapman, Colin A; Festa-Bianchet, Marco; Millien, Virginie; Rioux-Paquette, Sébastien; Pelletier, Fanie

2014-08-01

Existing and emerging infectious diseases are among the most pressing global threats to biodiversity, food safety and human health. The complex interplay between host, pathogen and environment creates a challenge for conserving species, communities and ecosystem functions, while mediating the many known ecological and socio-economic negative effects of disease. Despite the clear ecological and evolutionary contexts of host-pathogen dynamics, approaches to managing wildlife disease remain predominantly reactionary, focusing on surveillance and some attempts at eradication. A few exceptional studies have heeded recent calls for better integration of ecological concepts in the study and management of wildlife disease; however, evolutionary concepts remain underused. Applied evolution consists of four principles: evolutionary history, genetic and phenotypic variation, selection and eco-evolutionary dynamics. In this article, we first update a classical framework for understanding wildlife disease to integrate better these principles. Within this framework, we explore the evolutionary implications of environment-disease interactions. Subsequently, we synthesize areas where applied evolution can be employed in wildlife disease management. Finally, we discuss some future directions and challenges. Here, we underscore that despite some evolutionary principles currently playing an important role in our understanding of disease in wild animals, considerable opportunities remain for fostering the practice of evolutionarily enlightened wildlife disease management.

Not just black and white: pigment pattern development and evolution in vertebrates

PubMed Central

Mills, Margaret G.; Patterson, Larissa B.

2009-01-01

Animals display diverse colors and patterns that vary within and between species. Similar phenotypes appear in both closely related and widely divergent taxa. Pigment patterns thus provide an opportunity to explore how development is altered to produce differences in form and whether similar phenotypes share a common genetic basis. Understanding the development and evolution of pigment patterns requires knowledge of the cellular interactions and signaling pathways that produce those patterns. These complex traits provide unparalleled opportunities for integrating studies from ecology and behavior to molecular biology and biophysics. PMID:19073271

Effects of Vegetarian Nutrition–A Nutrition Ecological Perspective

PubMed Central

Metz, Martina; Hoffmann, Ingrid

2010-01-01

Although vegetarian nutrition is a complex issue, the multidimensionality and interrelatedness of its effects are rarely explored. This article aims to demonstrate the complexity of vegetarian nutrition by means of the nutrition ecological modeling technique NutriMod. The integrative qualitative cause-effect model, which is based on scientific literature, provides a comprehensive picture of vegetarian nutrition. The nutrition ecological perspective offers a basis for the assessment of the effects of worldwide developments concerning shifts in diets and the effects of vegetarian nutrition on global problems like climate change. Furthermore, new research areas on the complexity of vegetarian nutrition can be identified. PMID:22254037

Characterizing the next-generation matrix and basic reproduction number in ecological epidemiology.

PubMed

Roberts, M G; Heesterbeek, J A P

2013-03-01

We address the interaction of ecological processes, such as consumer-resource relationships and competition, and the epidemiology of infectious diseases spreading in ecosystems. Modelling such interactions seems essential to understand the dynamics of infectious agents in communities consisting of interacting host and non-host species. We show how the usual epidemiological next-generation matrix approach to characterize invasion into multi-host communities can be extended to calculate R₀, and how this relates to the ecological community matrix. We then present two simple examples to illustrate this approach. The first of these is a model of the rinderpest, wildebeest, grass interaction, where our inferred dynamics qualitatively matches the observed phenomena that occurred after the eradication of rinderpest from the Serengeti ecosystem in the 1980s. The second example is a prey-predator system, where both species are hosts of the same pathogen. It is shown that regions for the parameter values exist where the two host species are only able to coexist when the pathogen is present to mediate the ecological interaction.

Pollinators, pests, and predators: Recognizing ecological trade-offs in agroecosystems.

PubMed

Saunders, Manu E; Peisley, Rebecca K; Rader, Romina; Luck, Gary W

2016-02-01

Ecological interactions between crops and wild animals frequently result in increases or declines in crop yield. Yet, positive and negative interactions have mostly been treated independently, owing partly to disciplinary silos in ecological and agricultural sciences. We advocate a new integrated research paradigm that explicitly recognizes cost-benefit trade-offs among animal activities and acknowledges that these activities occur within social-ecological contexts. Support for this paradigm is presented in an evidence-based conceptual model structured around five evidence statements highlighting emerging trends applicable to sustainable agriculture. The full range of benefits and costs associated with animal activities in agroecosystems cannot be quantified by focusing on single species groups, crops, or systems. Management of productive agroecosystems should sustain cycles of ecological interactions between crops and wild animals, not isolate these cycles from the system. Advancing this paradigm will therefore require integrated studies that determine net returns of animal activity in agroecosystems.

Can plant-natural enemy communication withstand disruption by biotic and abiotic factors?

PubMed

Clavijo McCormick, Andrea

2016-12-01

The attraction of natural enemies towards herbivore-induced plant volatiles is a well-documented phenomenon. However, the majority of published studies are carried under optimal water and nutrient regimes and with just one herbivore. But what happens when additional levels of ecological complexity are added? Does the presence of a second herbivore, microorganisms, and abiotic stress interfere with plant-natural enemy communication? or is communication stable enough to withstand disruption by additional biotic and abiotic factors?Investigating the effects of these additional levels of ecological complexity is key to understanding the stability of tritrophic interactions in natural ecosystems and may aid to forecast the impact of environmental disturbances on these, especially in climate change scenarios, which are often associated with modifications in plant and arthropod species distribution and increased levels of abiotic stress.This review explores the literature on natural enemy attraction to herbivore-induced volatiles when, besides herbivory, plants are challenged by additional biotic and abiotic factors.The aim of this review was to establish the impact of different biotic and abiotic factors on plant-natural enemy communication and to highlight critical aspects to guide future research efforts.

Immune Ecosystem of Virus-Infected Host Tissues.

PubMed

Maarouf, Mohamed; Rai, Kul Raj; Goraya, Mohsan Ullah; Chen, Ji-Long

2018-05-06

Virus infected host cells serve as a central immune ecological niche during viral infection and replication and stimulate the host immune response via molecular signaling. The viral infection and multiplication process involves complex intracellular molecular interactions between viral components and the host factors. Various types of host cells are also involved to modulate immune factors in delicate and dynamic equilibrium to maintain a balanced immune ecosystem in an infected host tissue. Antiviral host arsenals are equipped to combat or eliminate viral invasion. However, viruses have evolved with strategies to counter against antiviral immunity or hijack cellular machinery to survive inside host tissue for their multiplication. However, host immune systems have also evolved to neutralize the infection; which, in turn, either clears the virus from the infected host or causes immune-mediated host tissue injury. A complex relationship between viral pathogenesis and host antiviral defense could define the immune ecosystem of virus-infected host tissues. Understanding of the molecular mechanism underlying this ecosystem would uncover strategies to modulate host immune function for antiviral therapeutics. This review presents past and present updates of immune-ecological components of virus infected host tissue and explains how viruses subvert the host immune surveillances.

Biochemical and physiological bases for the use of carbon and nitrogen isotopes in environmental and ecological studies

NASA Astrophysics Data System (ADS)

Ohkouchi, Naohiko; Ogawa, Nanako O.; Chikaraishi, Yoshito; Tanaka, Hiroyuki; Wada, Eitaro

2015-12-01

We review the biochemical and physiological bases of the use of carbon and nitrogen isotopic compositions as an approach for environmental and ecological studies. Biochemical processes commonly observed in the biosphere, including the decarboxylation and deamination of amino acids, are the key factors in this isotopic approach. The principles drawn from the isotopic distributions disentangle the complex dynamics of the biosphere and allow the interactions between the geosphere and biosphere to be analyzed in detail. We also summarize two recently examined topics with new datasets: the isotopic compositions of individual biosynthetic products (chlorophylls and amino acids) and those of animal organs for further pursuing the basis of the methodology. As a tool for investigating complex systems, compound-specific isotopic analysis compensates the intrinsic disadvantages of bulk isotopic signatures. Chlorophylls provide information about the particular processes of various photoautotrophs, whereas amino acids provide a precise measure of the trophic positions of heterotrophs. The isotopic distributions of carbon and nitrogen in a single organism as well as in the whole biosphere are strongly regulated, so that their major components such as amino acids are coordinated appropriately rather than controlled separately.

Multidisciplinary studies of wildlife trade in primates: Challenges and priorities.

PubMed

Blair, Mary E; Le, Minh D; Sterling, Eleanor J

2017-11-01

Wildlife trade is increasingly recognized as an unsustainable threat to primate populations and informing its management is a growing focus and application of primatological research. However, management policies based on ecological research alone cannot address complex socioeconomic or cultural contexts as drivers of wildlife trade. Multidisciplinary research is required to understand trade complexity and identify sustainable management strategies. Here, we define multidisciplinary research as research that combines more than one academic discipline, and highlight how the articles in this issue combine methods and approaches to fill key gaps and offer a more comprehensive understanding of underlying drivers of wildlife trade including consumer demand, enforcement patterns, source population status, and accessibility of targeted species. These articles also focus on how these drivers interact at different scales, how trade patterns relate to ethics, and the potential effectiveness of different policy interventions in reducing wildlife trade. We propose priorities for future research on primate trade including expanding from multidisciplinary to interdisciplinary research questions and approaches co-created by research teams that integrate across different disciplines such as cultural anthropology, ecology, economics, and public policy. We also discuss challenges that limit the integration of information across disciplines to meet these priorities. © 2017 Wiley Periodicals, Inc.

Identifying common pressure pathways from a complex network of human activities to support ecosystem-based management.

PubMed

Knights, Antony M; Koss, Rebecca S; Robinson, Leonie A

2013-06-01

The marine environment is heavily exploited, but unintentional consequences cause wide-ranging negative effects to its characteristics. Linkage frameworks (e.g., DPSIR [driver-pressure-state-impact-response]) are commonly used to describe an interaction between human activities and ecological characteristics of the ecosystem, but as each linkage is viewed independently, the diversity of pressures that affect those characteristics may not be identified or managed effectively. Here we demonstrate an approach for using linkages to build a simple network to capture the complex relationships arising from multiple sectors and their activities. Using data-analysis tools common to ecology, we show how linkages can be placed into mechanistically similar groups. Management measures can be combined into fewer and more simplified measures that target groups of pressures rather than individual pressures, which is likely to increase compliance and the success of the measure while reducing the cost of enforcement. Given that conservation objectives (regional priorities) can vary, we also demonstrate by way of a case study example from the Marine Strategy Framework Directive, how management priorities might change, and illustrate how the approach can be used to identify sectors for control that best support the conservation objectives.