scholarly journals A residence-time framework for biodiversity

2017 ◽  
Author(s):  
Kenneth J Locey ◽  
Jay T Lennon
Keyword(s):  
Residence Time ◽  
Physical Environment ◽  
Distinct Species ◽  
Ecological Systems ◽  
Complex Environments ◽  
Average Amount ◽  
Resource Limited ◽  
Trade Offs ◽  
Limited Life ◽  
Individual Based Models

Residence time (τ) is the average amount of time that particles spend in an ecosystem. Often estimated from the ratio of volume to flow rate, τ equates the physical environment with dynamics of growth. Here, we propose that τ is key to understanding relationships between biodiversity and the physical ecosystem. We hypothesize that τ acts as a force of selection on traits related to growth and persistence by coupling dispersal and resource supply. We test a suite of predictions using >10,000 stochastic individual-based models that simulate resource-limited life history among ecologically distinct species within complex environments. Predicted relationships between τ and abundance, productivity, and diversity emerged alongside realistic macroecological patterns. Abundance and productivity were greatest when τ equaled an emergent property ϕ, which captures energy-based trade-offs between growth and persistence. From individual metabolism to the dynamics of bioreactors, soils, lakes, and oceans, ecological systems should inherently be governed by τ.

scholarly journals A modeling platform for the simultaneous emergence of ecological patterns

2017 ◽  
Author(s):  
Kenneth J Locey ◽  
Jay T. Lennon
Keyword(s):  
Species Traits ◽  
Basic Principles ◽  
Ecological Selection ◽  
Resource Limited ◽  
Trade Offs ◽  
Individual Based Models ◽  
Holistic Understanding ◽  
Simulation Based ◽  
Ecological Patterns ◽  
Starting Conditions

Patterns underpin ecological theories and paradigms. While over a dozen ecological patterns are considered to be classic or even law-like, most are divided among non-overlapping theories and subfields. As a result, ecology lacks a holistic understanding for how primary patterns can emerge in unison. We developed a simulation-based platform for this purpose. The Emergence platform encodes energetic costs, ecological selection, stochasticity, and multiplicative interactions. These phenomena capture the basis of life history trade-offs, resource-limited growth, the importance of stochasticity and determinism, and the nonlinear nature of ecological dynamics. Emergence builds individual-based models from random starting conditions and allows ecological selection to operate on random variation in species traits. Emergence generates established patterns of commonness and rarity, scaling patterns from metabolic theory and biodiversity theory, growth and abundance patterns of population ecology. Our platform reveals that iconic ecological patterns that span paradigms, theories, and sub-disciplines can simultaneously emerge from random starting conditions when basic principles are observed.

scholarly journals A modeling platform for the simultaneous emergence of ecological patterns

2017 ◽  
Author(s):  
Kenneth J Locey ◽  
Jay T. Lennon
Keyword(s):  
Species Traits ◽  
Basic Principles ◽  
Ecological Selection ◽  
Resource Limited ◽  
Trade Offs ◽  
Individual Based Models ◽  
Holistic Understanding ◽  
Simulation Based ◽  
Ecological Patterns ◽  
Starting Conditions

Patterns underpin ecological theories and paradigms. While over a dozen ecological patterns are considered to be classic or even law-like, most are divided among non-overlapping theories and subfields. As a result, ecology lacks a holistic understanding for how primary patterns can emerge in unison. We developed a simulation-based platform for this purpose. The Emergence platform encodes energetic costs, ecological selection, stochasticity, and multiplicative interactions. These phenomena capture the basis of life history trade-offs, resource-limited growth, the importance of stochasticity and determinism, and the nonlinear nature of ecological dynamics. Emergence builds individual-based models from random starting conditions and allows ecological selection to operate on random variation in species traits. Emergence generates established patterns of commonness and rarity, scaling patterns from metabolic theory and biodiversity theory, growth and abundance patterns of population ecology. Our platform reveals that iconic ecological patterns that span paradigms, theories, and sub-disciplines can simultaneously emerge from random starting conditions when basic principles are observed.

scholarly journals Escherichia colipopulations adapt to complex, unpredictable fluctuations without any trade-offs across environments

2016 ◽  
Author(s):  
Shraddha Karve ◽  
Devika Bhave ◽  
Dhanashri Nevgi ◽  
Sutirth Dey
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Growth Rates ◽  
Complex Environments ◽  
Multiple Stresses ◽  
Trade Off ◽  
Trade Offs ◽  
Fluctuating Environments ◽  
Laboratory Populations ◽  
Lower Variation

AbstractIn nature, organisms are simultaneously exposed to multiple stresses (i.e. complex environments) that often fluctuate unpredictably. While both these factors have been studied in isolation, the interaction of the two remains poorly explored. To address this issue, we selected laboratory populations ofEscherichia coliunder complex (i.e. stressful combinations of pH, H2O2and NaCl) unpredictably fluctuating environments for ~900 generations. We compared the growth rates and the corresponding trade-off patterns of these populations to those that were selected under constant values of the component stresses (i.e. pH, H2O2and NaCl) for the same duration. The fluctuation-selected populations had greater mean growth rate and lower variation for growth rate over all the selection environments experienced. However, while the populations selected under constant stresses experienced severe tradeoffs in many of the environments other than those in which they were selected, the fluctuation-selected populations could by-pass the across-environment trade-offs completely. Interestingly, trade-offs were found between growth rates and carrying capacities. The results suggest that complexity and fluctuations can strongly affect the underlying trade-off structure in evolving populations.

Should I stay or should I go? Complex environments influence the developmental plasticity of flight capacity and flight-related trade-offs

2019 ◽  
Vol 128 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Jordan R Glass ◽  
Zachary R Stahlschmidt
Keyword(s):  
Life History ◽  
Food Availability ◽  
Life History Traits ◽  
Developmental Plasticity ◽  
Temperature Variability ◽  
Field Cricket ◽  
Valuable Insight ◽  
Complex Environments ◽  
Trade Offs ◽  
Flight Capacity

Abstract Complex environments, characterized by co-varying factors (e.g. temperature and food availability) may cause animals to invest resources differentially into fitness-related traits. Thus, experiments manipulating multiple environmental factors concurrently provide valuable insight into the role of the environment in shaping not only important traits (e.g. dispersal capacity or reproduction), but also trait–trait interactions (e.g. trade-offs between traits). We used a multi-factorial design to manipulate variation in temperature (constant 28 °C vs. 28 ± 5 °C daily cycle) and food availability (unlimited vs. intermittent access) throughout development in the sand field cricket (Gryllus firmus). Using a univariate approach, we found that temperature variability and unlimited food availability promoted survival, development, growth, body size and/or reproductive investment. Using principal components as indices of resource allocation strategy, we found that temperature variability and unlimited food reduced investment into flight capacity in females. Thus, we detected a sex-specific trade-off between flight and other life-history traits that was developmentally plastic in response to variation in temperature and food availability. We develop an experimental and statistical framework to reveal shifts in correlative patterns of investment into different life-history traits. This approach can be applied to a range of biological systems to investigate how environmental complexity influences traits and trait trade-offs.

scholarly journals Cross-Scale Value Trade-Offs in Managing Social-Ecological Systems: The Politics of Scale in Ruaha National Park, Tanzania

2011 ◽  
Vol 16 (4) ◽  
Author(s):  
Asim Zia ◽  
Paul Hirsch ◽  
Alexander Songorwa ◽  
David R. Mutekanga ◽  
Sheila O'Connor ◽  
...  
Keyword(s):  
National Park ◽  
Ecological Systems ◽  
Politics Of Scale ◽  
Social Ecological Systems ◽  
Social Ecological ◽  
Trade Offs ◽  
Ruaha National Park

Distribution des brachiopodes en especes et ses causes, illustree par les terebratulinides de l'Eocene de l'Europe occidentale

1947 ◽  
Vol S5-XVII (1-3) ◽  
pp. 67-80 ◽  
Author(s):  
Graham F. Elliott
Keyword(s):  
Rare Species ◽  
Physical Environment ◽  
Western Europe ◽  
Distinct Species ◽  
Discontinuous Groups

Abstract Study of terebratulinids from the Eocene of western Europe shows that an unfavorable biologic environment (abundance of mollusks) rather than the physical environment was responsible for speciation, on the basis of the concept that rare species tend to subdivide into discontinuous groups which in turn exhibit a tendency to subdivide into distinct species. The decline of brachiopods in the Tertiary was not due to modifications of their structure or to degeneration, but to their constitutional inability to compete successfully with mollusks.

scholarly journals Wind and water tunnel testing of a morphing aquatic micro air vehicle

2017 ◽  
Vol 7 (1) ◽  
pp. 20160085 ◽  
Author(s):  
Robert Siddall ◽  
Alejandro Ortega Ancel ◽  
Mirko Kovač
Keyword(s):  
Field Tests ◽  
Micro Air Vehicle ◽  
Water Tunnel ◽  
Complex Environments ◽  
Aerial Robots ◽  
Dive Behaviour ◽  
Trade Offs ◽  
Planar Trajectory ◽  
Air Vehicle ◽  
The Family

Aerial robots capable of locomotion in both air and water would enable novel mission profiles in complex environments, such as water sampling after floods or underwater structural inspections. The design of such a vehicle is challenging because it implies significant propulsive and structural design trade-offs for operation in both fluids. In this paper, we present a unique Aquatic Micro Air Vehicle (AquaMAV), which uses a reconfigurable wing to dive into the water from flight, inspired by the plunge diving strategy of water diving birds in the family Sulidae . The vehicle's performance is investigated in wind and water tunnel experiments, from which we develop a planar trajectory model. This model is used to predict the dive behaviour of the AquaMAV, and investigate the efficacy of passive dives initiated by wing folding as a means of water entry. The paper also includes first field tests of the AquaMAV prototype where the folding wings are used to initiate a plunge dive.

Heat Transfer Models of Moving Packed-Bed Particle-to-SCO2 Heat Exchangers

2017 ◽  
Author(s):  
Kevin J. Albrecht ◽  
Clifford K. Ho
Keyword(s):  
Heat Transfer ◽  
Particle Size ◽  
Residence Time ◽  
Heat Exchangers ◽  
High Efficiency ◽  
Operating Temperature ◽  
Constitutive Relations ◽  
Packed Bed ◽  
Working Fluid ◽  
Trade Offs

Particle-based concentrating solar power (CSP) plants have been proposed to increase operating temperature for integration with higher efficiency power cycles using supercritical carbon dioxide (sCO2). The majority of research to date has focused on the development of high-efficiency and high-temperature particle solar thermal receivers. However, system realization will require the design of a particle/sCO2 heat exchanger as well for delivering thermal energy to the power-cycle working fluid. Recent work has identified moving packed-bed heat exchangers as low-cost alternatives to fluidized-bed heat exchangers, which require additional pumps to fluidize the particles and recuperators to capture the lost heat. However, the reduced heat transfer between the particles and the walls of moving packed-bed heat exchangers, compared to fluidized beds, causes concern with adequately sizing components to meet the thermal duty. Models of moving packed-bed heat exchangers are not currently capable of exploring the design trade-offs in particle size, operating temperature, and residence time. The present work provides a predictive numerical model based on literature correlations capable of designing moving packed-bed heat exchangers as well as investigating the effects of particle size, operating temperature, and particle velocity (residence time). Furthermore, the development of a reliable design tool for moving packed-bed heat exchangers must be validated by predicting experimental results in the operating regime of interest. An experimental system is designed to provide the data necessary for model validation and/or to identify where deficiencies or new constitutive relations are needed.

scholarly journals Monitoring social–ecological networks for biodiversity and ecosystem services in human-dominated landscapes

FACETS ◽  
2021 ◽  
Vol 6 ◽  
pp. 1670-1692
Author(s):  
Carina Rauen Firkowski ◽  
Amanda M. Schwantes ◽  
Marie-Josée Fortin ◽  
Andrew Gonzalez
Keyword(s):  
Ecosystem Services ◽  
Ecosystem Service ◽  
Ecological Systems ◽  
Maple Syrup ◽  
Spatial And Temporal Scales ◽  
Causal Understanding ◽  
Social Ecological Systems ◽  
Social Ecological ◽  
Trade Offs ◽  
Analytical Tools

The demand the human population is placing on the environment has triggered accelerated rates of biodiversity change and created trade-offs among the ecosystem services we depend upon. Decisions designed to reverse these trends require the best possible information obtained by monitoring ecological and social dimensions of change. Here, we conceptualize a network framework to monitor change in social–ecological systems. We contextualize our framework within Ostrom’s social–ecological system framework and use it to discuss the challenges of monitoring biodiversity and ecosystem services across spatial and temporal scales. We propose that spatially explicit multilayer and multiscale monitoring can help estimate the range of variability seen in social–ecological systems with varying levels of human modification across the landscape. We illustrate our framework using a conceptual case study on the ecosystem service of maple syrup production. We argue for the use of analytical tools capable of integrating qualitative and quantitative knowledge of social–ecological systems to provide a causal understanding of change across a network. Altogether, our conceptual framework provides a foundation for establishing monitoring systems. Operationalizing our framework will allow for the detection of ecosystem service change and assessment of its drivers across several scales, informing the long-term sustainability of biodiversity and ecosystem services.

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