Gathering knowledge on mesopelagic ecosystems: insights from a parsimonious modelling approach

2020 ◽  
Author(s):  
Anna Conchon ◽  
Olivier Titaud ◽  
Inna Senina ◽  
Beatriz Calmettes ◽  
Audrey Delpech ◽  
...  
Keyword(s):  
Functional Groups ◽  
Parameters Estimation ◽  
Trophic Levels ◽  
Spatially Explicit ◽  
Vertical Layer ◽  
Modeling Framework ◽  
Acoustic Data ◽  
Future Challenges ◽  
Global Datasets ◽  
Modelling Approach

<p><span xml:lang="EN-US" data-contrast="none"><span>SEAPODYM-LMTL is the Lower (zooplankton) and Mid (micronekton) Trophic levels model of the Spatial Ecosystem </span></span><span xml:lang="EN-US" data-contrast="none"><span>And</span></span><span xml:lang="EN-US" data-contrast="none"><span> </span></span><span xml:lang="EN-US" data-contrast="none"><span>POpulation</span></span><span xml:lang="EN-US" data-contrast="none"><span> </span></span><span xml:lang="EN-US" data-contrast="none"><span>DYnamic</span></span><span xml:lang="EN-US" data-contrast="none"><span> Modeling framework. Currently, there is one zooplankton and 6 micronekton functional groups defined according to their vertical behavior and development times. The model is global and spatially explicit with transport described through a system of advection-diffusion equations. The vertical dimension is simplified into three layers -- epipelagic, upper and lower mesopelagic -- defined relatively to the euphotic depth. There are three vertically migrant and three non-migrant functional groups. The model is parsimonious with only a few parameters (6 for the zooplankton and 11 for the micronekton) that control the energy transfer efficiency from the primary production and the mortality and time of development that are linked to the water temperature. A data assimilation framework has been implemented to estimate those parameters.  We present briefly the latest results and future challenges of this model. They include the validation of vertical layer boundaries, the first zooplankton and micronekton parameters estimation using existing biomass observations, and the developments needed to use large global datasets of acoustic data.</span></span><span> </span></p>

scholarly journals The importance of species interactions in spatially explicit eco-evolutionary community dynamics under climate change

2020 ◽  
Author(s):  
Anna Åkesson ◽  
Alva Curtsdotter ◽  
Anna Eklöf ◽  
Bo Ebenman ◽  
Jon Norberg ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Interactions ◽  
Community Dynamics ◽  
Evolutionary Dynamics ◽  
Negative Relationship ◽  
Trophic Levels ◽  
Spatially Explicit ◽  
Modeling Framework ◽  
Impact Of Climate Change ◽  
The Impact

AbstractEco-evolutionary dynamics are essential in shaping the biological response of communities to ongoing climate change. Here we develop a spatially explicit eco-evolutionary framework which integrates evolution, dispersal, and species interactions within and between trophic levels. This allows us to analyze how these processes interact to shape species- and community-level dynamics under climate change. Additionally, we incorporate the heretofore unexplored feature that species interactions themselves might change due to increasing temperatures and affect the impact of climate change on ecological communities. The new modeling framework captures previously reported ecological responses to climate change, and also reveals two new key results. First, interactions between trophic levels as well as temperature-dependent competition within a trophic level mitigate the negative impact of climate change on global biodiversity, emphasizing the importance of understanding biotic interactions in shaping climate change impact. Second, using a trait-based perspective, we found a strong negative relationship between the within-community variation in preferred temperatures and the capacity to respond to climate change. Communities resulting from different ecological interaction structures form distinct clusters along this relationship, but varying species’ abilities to disperse and adapt to new temperatures leave it unaffected.

Modelling Gas Processing Unit: An Inter-disciplinary Approach Based on Petri Nets

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Sanda Florentina Mihalache
Keyword(s):  
Industrial Process ◽  
Industrial Processes ◽  
Processing Unit ◽  
Industrial System ◽  
Modeling Framework ◽  
Gas Processing ◽  
Human Interactions ◽  
Modelling Method ◽  
Effective Representation ◽  
Modelling Approach

A modelling approach that will facilitate an in-depth understanding of the interactions of the different phenomena, human interactions and environmental factors constituting �real world� industrial processes is presented. An important industrial system such as Gas Processing Unit (GPU) have inter-related internal process activities coexisting with external events and requires a real time inter-disciplinary approach to model them. This modeling framework is based on identifying as modules, the part of processes that have interactions and can be considered active participants in overall behaviour. The selected initial set of modules are structured as Petri net models and made to interact iteratively to provide process states of the system. The modeling goal is accomplished by identifying the evolution of the process states as a means of effective representation of the �actual running�� of the industrial process. The paper discusses the function and the implementation of the modelling method as applicable to the industrial case of GPU.

scholarly journals The importance of species interactions in eco-evolutionary community dynamics under climate change

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anna Åkesson ◽  
Alva Curtsdotter ◽  
Anna Eklöf ◽  
Bo Ebenman ◽  
Jon Norberg ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Interactions ◽  
Community Dynamics ◽  
Evolutionary Dynamics ◽  
Negative Impact ◽  
Trophic Levels ◽  
Temperature Dependent ◽  
Modeling Framework ◽  
Impact Of Climate Change ◽  
The Impact

AbstractEco-evolutionary dynamics are essential in shaping the biological response of communities to ongoing climate change. Here we develop a spatially explicit eco-evolutionary framework which features more detailed species interactions, integrating evolution and dispersal. We include species interactions within and between trophic levels, and additionally, we incorporate the feature that species’ interspecific competition might change due to increasing temperatures and affect the impact of climate change on ecological communities. Our modeling framework captures previously reported ecological responses to climate change, and also reveals two key results. First, interactions between trophic levels as well as temperature-dependent competition within a trophic level mitigate the negative impact of climate change on biodiversity, emphasizing the importance of understanding biotic interactions in shaping climate change impact. Second, our trait-based perspective reveals a strong positive relationship between the within-community variation in preferred temperatures and the capacity to respond to climate change. Temperature-dependent competition consistently results both in higher trait variation and more responsive communities to altered climatic conditions. Our study demonstrates the importance of species interactions in an eco-evolutionary setting, further expanding our knowledge of the interplay between ecological and evolutionary processes.

Advanced open rotor noise prediction

2014 ◽  
Vol 118 (1208) ◽  
pp. 1125-1135 ◽  
Author(s):  
M. J. Kingan
Keyword(s):  
High Speed ◽  
Broadband Noise ◽  
Current Status ◽  
Prediction Methods ◽  
Noise Prediction ◽  
Acoustic Data ◽  
Rotor Noise ◽  
Future Challenges ◽  
Open Rotor ◽  
Development And Validation

Abstract The purpose of this paper is to describe the current status of open rotor noise prediction methods and to highlight future challenges in this area. A number of analytic and numerical methods are described which can be used for predicting ‘isolated’ and ‘installed’ open rotor tonal noise. Broadband noise prediction methods are also described and it is noted that further development and validation of the current models is required. The paper concludes with a discussion of the analytical methods which are used to assess the acoustic data collected during the high-speed wind-tunnel testing of a model scale advanced open rotor rig.

scholarly journals Making better sense of monitoring data from low density species using a spatially explicit modelling approach

2010 ◽  
Vol 48 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Max Post van der Burg ◽  
Bartholomew Bly ◽  
Tammy VerCauteren ◽  
Andrew J. Tyre
Keyword(s):  
Monitoring Data ◽  
Spatially Explicit ◽  
Low Density ◽  
Modelling Approach

scholarly journals Climate and human development impacts on municipal water demand: A spatially-explicit global modeling framework

2016 ◽  
Vol 85 ◽  
pp. 266-278 ◽  
Author(s):  
Simon C. Parkinson ◽  
Nils Johnson ◽  
Narasimha D. Rao ◽  
Bryan Jones ◽  
Michelle T.H. van Vliet ◽  
...  
Keyword(s):  
Human Development ◽  
Water Demand ◽  
Spatially Explicit ◽  
Modeling Framework ◽  
Global Modeling ◽  
Municipal Water

Modeling mercury cycling in the marine environment

2020 ◽  
Author(s):  
Johannes Bieser ◽  
Ute Daewel ◽  
Corinna Schrum
Keyword(s):  
Numerical Models ◽  
Marine Ecosystem ◽  
Ecosystem Model ◽  
Trophic Levels ◽  
Modeling Framework ◽  
Modeling Tools ◽  
Large Variability ◽  
Marine Ecosystem Model ◽  
Set Up ◽  
Fully Coupled

<p>Five decades of Hg science have shown the <strong>tremendous complexity of the global Hg cycle</strong>. Yet, the pathways that lead from anthropogenic Hg emissions to MeHg exposure through sea food are not fully comprehended. Moreover, the observed amount of MeHg in fish exhibits a large temporal and spatial variability that we cannot predict yet. A key issue is that fully speciated Hg measurements in the ocean are difficult to perform and thus we will never be able to achieve a comprehensive spatial and temporal coverage.</p><p>Therefore, we need complex modeling tools that allow us to fill the gaps in the observations and to predict future changes in the system under changing external drivers (emissions, climate change, ecosystem changes). Numerical models have a long history in Hg research, but so far have virtually only addressed inorganic Hg cycling in atmosphere and oceans.</p><p>Here we present a novel 3d-hydrodynamic mercury modeling framework based on fully coupled compartmental models including atmosphere, ocean, and ecosystem. The generalized high resolution model has been set up for European shelf seas and was used to model the transition zone from estuaries to the open ocean. Based on this model we present our findings on intra- and inter-annual dynamics and variability of mercury speciation and distribution in a coastal ocean. Moreover, we present the first results on the dynamics of mercury bio-accumulation from a fully coupled marine ecosystem model. Most importantly, the model is able to reproduce the large variability in methylmercury accumulation in higher trophic levels.</p>

Lake Michigan offshore ecosystem structure and food web changes from 1987 to 2008

2014 ◽  
Vol 71 (7) ◽  
pp. 1072-1086 ◽  
Author(s):  
Mark W. Rogers ◽  
David B. Bunnell ◽  
Charles P. Madenjian ◽  
David M. Warner
Keyword(s):  
Food Web ◽  
Functional Groups ◽  
Lake Michigan ◽  
Neogobius Melanostomus ◽  
Trophic Levels ◽  
Nutrient Concentrations ◽  
Ecosystem Structure ◽  
Bythotrephes Longimanus ◽  
Nutrient Inputs ◽  
Food Web Structure

Ecosystems undergo dynamic changes owing to species invasions, fisheries management decisions, landscape modifications, and nutrient inputs. At Lake Michigan, new invaders (e.g., dreissenid mussels (Dreissena spp.), spiny water flea (Bythotrephes longimanus), round goby (Neogobius melanostomus)) have proliferated and altered energy transfer pathways, while nutrient concentrations and stocking rates to support fisheries have changed. We developed an ecosystem model to describe food web structure in 1987 and ran simulations through 2008 to evaluate changes in biomass of functional groups, predator consumption, and effects of recently invading species. Keystone functional groups from 1987 were identified as Mysis, burbot (Lota lota), phytoplankton, alewife (Alosa pseudoharengus), nonpredatory cladocerans, and Chinook salmon (Oncorhynchus tshawytscha). Simulations predicted biomass reductions across all trophic levels and predicted biomasses fit observed trends for most functional groups. The effects of invasive species (e.g., dreissenid grazing) increased across simulation years, but were difficult to disentangle from other changes (e.g., declining offshore nutrient concentrations). In total, our model effectively represented recent changes to the Lake Michigan ecosystem and provides an ecosystem-based tool for exploring future resource management scenarios.

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