Identifying patterns in the multitrophic community and food-web structure of a low-turbidity temperate estuarine bay

Abstract Food web dynamics outline the ecosystem processes that regulate community structure. Challenges in the approaches used to capture topological descriptions of food webs arise due to the difficulties in collecting extensive empirical data with temporal and spatial variations in community structure and predator–prey interactions. Here, we use a Kohonen self-organizing map algorithm (as a measure of community pattern) and stable isotope-mixing models (as a measure of trophic interaction) to identify food web patterns across a low-turbidity water channel of a temperate estuarine-coastal continuum. We find a spatial difference in the patterns of community compositions between the estuarine and deep-bay channels and a seasonal difference in the plankton pattern but less in the macrobenthos and nekton communities. Dietary mixing models of co-occurring dominant taxa reveal site-specific but unchanging food web topologies and the prominent role of phytoplankton in the trophic base of pelagic and prevalent-detrital benthic pathways. Our approach provides realistic frameworks for linking key nodes from producers to predators in trophic networks.

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Analysis of complex trophic networks reveals the signature of land-use intensification on soil communities in agroecosystems

Scientific Reports ◽

10.1038/s41598-021-97300-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Juliette M. G. Bloor ◽

Sara Si-Moussi ◽

Pierre Taberlet ◽

Pascal Carrère ◽

Mickaël Hedde

Keyword(s):

Land Use ◽

Food Web ◽

Agricultural Intensification ◽

Environmental Dna ◽

Trophic Group ◽

Interaction Networks ◽

Land Use Intensity ◽

Food Web Structure ◽

Trophic Networks ◽

Management Intensity

AbstractIncreasing evidence suggests that agricultural intensification is a threat to many groups of soil biota, but how the impacts of land-use intensity on soil organisms translate into changes in comprehensive soil interaction networks remains unclear. Here for the first time, we use environmental DNA to examine total soil multi-trophic diversity and food web structure for temperate agroecosystems along a gradient of land-use intensity. We tested for response patterns in key properties of the soil food webs in sixteen fields ranging from arable crops to grazed permanent grasslands as part of a long-term management experiment. We found that agricultural intensification drives reductions in trophic group diversity, although taxa richness remained unchanged. Intensification generally reduced the complexity and connectance of soil interaction networks and induced consistent changes in energy pathways, but the magnitude of management-induced changes depended on the variable considered. Average path length (an indicator of food web redundancy and resilience) did not respond to our management intensity gradient. Moreover, turnover of network structure showed little response to increasing management intensity. Our data demonstrates the importance of considering different facets of trophic networks for a clearer understanding of agriculture-biodiversity relationships, with implications for nature-based solutions and sustainable agriculture.

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Role of TEP in the microbial food web structure. II. Influence on the ciliate community structure

Marine Ecology Progress Series ◽

10.3354/meps279023 ◽

2004 ◽

Vol 279 ◽

pp. 23-32 ◽

Cited By ~ 8

Author(s):

X Mari ◽

F Rassoulzadegan ◽

CPD Brussaard

Keyword(s):

Community Structure ◽

Food Web ◽

Microbial Food Web ◽

Food Web Structure ◽

Ciliate Community ◽

Web Structure

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Modification of benthic food web structure by recovering seagrass meadows, as revealed by trophic markers and mixing models

Ecological Indicators ◽

10.1016/j.ecolind.2018.02.054 ◽

2018 ◽

Vol 90 ◽

pp. 28-37 ◽

Cited By ~ 9

Author(s):

Emilia Jankowska ◽

Marleen De Troch ◽

Loïc N. Michel ◽

Gilles Lepoint ◽

Maria Włodarska-Kowalczuk

Keyword(s):

Food Web ◽

Mixing Models ◽

Food Web Structure ◽

Benthic Food Web ◽

Seagrass Meadows ◽

Web Structure ◽

Benthic Food ◽

Trophic Markers

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Predicting the effects of temperature on food web connectance

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2010.0011 ◽

2010 ◽

Vol 365 (1549) ◽

pp. 2081-2091 ◽

Cited By ~ 90

Author(s):

Owen L. Petchey ◽

Ulrich Brose ◽

Björn C. Rall

Keyword(s):

Community Structure ◽

Food Web ◽

Food Webs ◽

Temperature Effects ◽

Diet Breadth ◽

The Body ◽

Large Temperature ◽

Temperature Sensitive ◽

Food Web Structure ◽

Resource Item

Few models concern how environmental variables such as temperature affect community structure. Here, we develop a model of how temperature affects food web connectance, a powerful driver of population dynamics and community structure. We use the Arrhenius equation to add temperature dependence of foraging traits to an existing model of food web structure. The model predicts potentially large temperature effects on connectance. Temperature-sensitive food webs exhibit slopes of up to 0.01 units of connectance per 1°C change in temperature. This corresponds to changes in diet breadth of one resource item per 2°C (assuming a food web containing 50 species). Less sensitive food webs exhibit slopes down to 0.0005, which corresponds to about one resource item per 40°C. Relative sizes of the activation energies of attack rate and handling time determine whether warming increases or decreases connectance. Differences in temperature sensitivity are explained by differences between empirical food webs in the body size distributions of organisms. We conclude that models of temperature effects on community structure and dynamics urgently require considerable development, and also more and better empirical data to parameterize and test them.

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Plant-mediated community structure of spring-fed, coastal rivers

10.1101/678128 ◽

2019 ◽

Author(s):

Matthew V. Lauretta ◽

William E. Pine ◽

Carl J. Walters ◽

Thomas K. Frazer

Keyword(s):

Community Structure ◽

Primary Production ◽

Food Web ◽

Vascular Plant ◽

Search Efficiency ◽

Top Down ◽

Food Web Structure ◽

Bottom Up ◽

Model Predictions ◽

Filamentous Macroalgae

AbstractQuantifying ecosystem-level processes that drive community structure and function is key to the development of effective environmental restoration and management programs. To assess the effects of large-scale aquatic vegetation loss on fish and invertebrate communities in Florida estuaries, we quantified and compared the food webs of two adjacent spring-fed rivers that flow into the Gulf of Mexico. We constructed a food web model using field-based estimates of community absolute biomass and trophic interactions of a highly productive vegetated river, and modeled long-term simulations of vascular plant decline coupled with seasonal production of filamentous macroalgae. We then compared ecosystem model predictions to observed community structure of the second river that has undergone extensive vegetative habitat loss, including extirpation of several vascular plant species. Alternative models incorporating bottom-up regulation (decreased primary production resulting from plant loss) versus coupled top-down effects (compensatory predator search efficiency) were ranked by goodness-of-fit tests of model predictions to the empirical community observations. Our best model for predicting community responses to vascular plant loss incorporated coupled effects of decreased primary production (bottom-up), increased prey search efficiency of large-bodied fishes at low vascular plant density (top-down), and decreased prey search efficiency of small-bodied fishes with increased biomass of filamentous macroalgae (bottom-up). The results of this study indicate that the loss of vascular plants from the coastal river ecosystem may alter the food web structure and result in a net decline in the biomass of fishes. These results are highly relevant to ongoing landscape-level restoration programs intended to improve aesthetics and ecosystem function of coastal spring-fed rivers by highlighting how the structure of these communities can be regulated both by resource availability and consumption. Restoration programs will need to acknowledge and incorporate both to be successful.

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Optimal Design of District Metered Areas in a Water Distribution Network Using Coupled Self-Organizing Map and Community Structure Algorithm

Water ◽

10.3390/w13060836 ◽

2021 ◽

Vol 13 (6) ◽

pp. 836

Author(s):

Xuan Khoa Bui ◽

Malvin S. Marlim ◽

Doosun Kang

Keyword(s):

Community Structure ◽

Optimal Design ◽

Water Distribution ◽

Distribution Network ◽

Coupled Model ◽

Water Distribution Network ◽

Self Organizing Map ◽

Structure Algorithm ◽

Demand Variability ◽

Self Organizing

Operation and management of a water distribution network (WDN) by district metered areas (DMAs) bring many benefits for water utilities, particularly regarding water loss control and pressure management. However, the optimal design of DMAs in a WDN is a challenging task. This paper proposes an approach for the optimal design of DMAs in the multiple-criteria decision analysis (MCDA) framework based on the outcome of a coupled model comprising a self-organizing map (SOM) and a community structure algorithm (CSA). First, the clustering principle of the SOM algorithm is applied to construct initial homologous clusters in terms of pressure and elevation. CSA is then coupled to refine the SOM-based initial clusters for the automated creation of multiscale and dynamic DMA layouts. Finally, the criteria for quantifying the performance of each DMA layout solution are assessed in the MCDA framework. Verifying the model on a hypothetical network and an actual WDN proved that it could efficiently create homologous and dynamic DMA layouts capable of adapting to water demand variability.

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