scholarly journals Novel feeding interactions amplify the impact of species redistribution on an Arctic food web

2020 ◽  
Vol 26 (9) ◽  
pp. 4894-4906
Author(s):  
Laurene Pecuchet ◽  
Marie‐Anne Blanchet ◽  
André Frainer ◽  
Bérengère Husson ◽  
Lis L. Jørgensen ◽  
...  
Keyword(s):  
Food Web ◽  
Arctic Food Web ◽  
The Impact ◽  
Feeding Interactions

scholarly journals Enhanced Viral Activity in the Surface Microlayer of the Arctic and Antarctic Oceans

2021 ◽  
Vol 9 (2) ◽  
pp. 317
Author(s):  
Dolors Vaqué ◽  
Julia A. Boras ◽  
Jesús Maria Arrieta ◽  
Susana Agustí ◽  
Carlos M. Duarte ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Food Web ◽  
Physicochemical Characteristics ◽  
The Arctic ◽  
Microbial Food Web ◽  
Surface Microlayer ◽  
Polar Regions ◽  
Nutrient Inputs ◽  
Viral Activity ◽  
The Impact

The ocean surface microlayer (SML), with physicochemical characteristics different from those of subsurface waters (SSW), results in dense and active viral and microbial communities that may favor virus–host interactions. Conversely, wind speed and/or UV radiation could adversely affect virus infection. Furthermore, in polar regions, organic and inorganic nutrient inputs from melting ice may increase microbial activity in the SML. Since the role of viruses in the microbial food web of the SML is poorly understood in polar oceans, we aimed to study the impact of viruses on prokaryotic communities in the SML and in the SSW in Arctic and Antarctic waters. We hypothesized that a higher viral activity in the SML than in the SSW in both polar systems would be observed. We measured viral and prokaryote abundances, virus-mediated mortality on prokaryotes, heterotrophic and phototrophic nanoflagellate abundance, and environmental factors. In both polar zones, we found small differences in environmental factors between the SML and the SSW. In contrast, despite the adverse effect of wind, viral and prokaryote abundances and virus-mediated mortality on prokaryotes were higher in the SML than in the SSW. As a consequence, the higher carbon flux released by lysed cells in the SML than in the SSW would increase the pool of dissolved organic carbon (DOC) and be rapidly used by other prokaryotes to grow (the viral shunt). Thus, our results suggest that viral activity greatly contributes to the functioning of the microbial food web in the SML, which could influence the biogeochemical cycles of the water column.

scholarly journals The impact of intraspecific variation on food web structure

Ecology ◽  
2018 ◽  
Vol 99 (12) ◽  
pp. 2712-2720 ◽  
Author(s):  
Tom Clegg ◽  
Mohammad Ali ◽  
Andrew P. Beckerman
Keyword(s):  
Food Web ◽  
Intraspecific Variation ◽  
Food Web Structure ◽  
Web Structure ◽  
The Impact

scholarly journals Untangling the roles of parasites in food webs with generative network models

2015 ◽  
Author(s):  
Abigail Z. Jacobs ◽  
Jennifer A. Dunne ◽  
Cristopher Moore ◽  
Aaron Clauset
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Statistical Physics ◽  
Network Models ◽  
Food Web Structure ◽  
Free Living ◽  
Web Structure ◽  
Living Species ◽  
Parasitic Interactions ◽  
The Impact

Food webs represent the set of consumer-resource interactions among a set of species that co-occur in a habitat, but most food web studies have omitted parasites and their interactions. Recent studies have provided conflicting evidence on whether including parasites changes food web structure, with some suggesting that parasitic interactions are structurally distinct from those among free-living species while others claim the opposite. Here, we describe a principled method for understanding food web structure that combines an efficient optimization algorithm from statistical physics called parallel tempering with a probabilistic generalization of the empirically well-supported food web niche model. This generative model approach allows us to rigorously estimate the degree to which interactions that involve parasites are statistically distinguishable from interactions among free-living species, whether parasite niches behave similarly to free-living niches, and the degree to which existing hypotheses about food web structure are naturally recovered. We apply this method to the well-studied Flensburg Fjord food web and show that while predation on parasites, concomitant predation of parasites, and parasitic intraguild trophic interactions are largely indistinguishable from free-living predation interactions, parasite-host interactions are different. These results provide a powerful new tool for evaluating the impact of classes of species and interactions on food web structure to shed new light on the roles of parasites in food webs.

An order-specific monoclonal antibody to Diptera reveals the impact of alternative prey on spider feeding behavior in a complex food web

2007 ◽  
Vol 41 (3) ◽  
pp. 397-407 ◽  
Author(s):  
James D. Harwood ◽  
Mark R. Bostrom ◽  
Erin E. Hladilek ◽  
David H. Wise ◽  
John J. Obrycki
Keyword(s):  
Monoclonal Antibody ◽  
Feeding Behavior ◽  
Food Web ◽  
Alternative Prey ◽  
Specific Monoclonal Antibody ◽  
The Impact

Lipid composition of zooplankton in relation to the sub-arctic food web

Polar Biology ◽  
1987 ◽  
Vol 8 (2) ◽  
pp. 115-120 ◽  
Author(s):  
Stig Falk-Petersen ◽  
John R. Sargent ◽  
Kurt S. Tande
Keyword(s):  
Food Web ◽  
Lipid Composition ◽  
Arctic Food Web

An Inverse Model Analysis of Planktonic Food Webs in Experimental Lakes

1994 ◽  
Vol 51 (9) ◽  
pp. 2034-2044 ◽  
Author(s):  
Alain F. Vézina ◽  
Michael L. Pace
Keyword(s):  
Food Web ◽  
Heterotrophic Bacteria ◽  
Grazing Pressure ◽  
Inverse Methods ◽  
Trophic Levels ◽  
Microbial Food Web ◽  
Food Web Structure ◽  
Planktonic Food ◽  
Size Groups ◽  
The Impact

We used inverse methods to reconstruct carbon flows in experimental lakes where the fish community had been purposely altered. These analyses were applied to three years of data from a reference lake and two experimental lakes located in Gogebic County, Michigan. We reconstructed seasonally averaged flows among two size groups of phytoplankton, heterotrophic bacteria, microzooplankton, cladocerans, and copepods. The inverse analysis produced significantly different flow networks for the different lakes that agreed qualitatively with known chemical and biological differences between lakes and with other analyses of the impact of fish manipulations on food web structure and dynamics. The results pointed to alterations in grazing pressure on the phytoplankton that parallel changes in the size and abundance of cladocerans and copepods among lakes. Estimated flows through the microbial food web indicated low bacterial production efficiencies and small carbon transfers from the microbial food web to the larger zooplankton. This study demonstrates the use of inverse methods to identify and compare flow patterns across ecosystems and suggests that microbial flows are relatively insensitive to changes at the upper trophic levels.

Transformation of Mercury at the Bottom of the Arctic Food Web: An Overlooked Puzzle in the Mercury Exposure Narrative

2014 ◽  
Vol 48 (13) ◽  
pp. 7280-7288 ◽  
Author(s):  
Monika Pućko ◽  
A. Burt ◽  
W. Walkusz ◽  
F. Wang ◽  
R. W. Macdonald ◽  
...  
Keyword(s):  
Food Web ◽  
Mercury Exposure ◽  
The Arctic ◽  
Arctic Food Web

scholarly journals The Dynamics of a Tritrophic Leslie-Gower Food-Web System with the Effect of Fear

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Firas Hussean Maghool ◽  
Raid Kamel Naji
Keyword(s):  
Food Web ◽  
Evolutionary Biology ◽  
Basin Of Attraction ◽  
Growth Function ◽  
Generalist Predator ◽  
Specific Level ◽  
Predator Species ◽  
Web System ◽  
Group Defense ◽  
The Impact

The avoidance strategy of prey to predation and the predation strategy for predators are important topics in evolutionary biology. Both prey and predators adjust their behaviors in order to obtain the maximal benefits and to raise their biomass for each. Therefore, this paper is aimed at studying the impact of prey’s fear and group defense against predation on the dynamics of the food-web model. Consequently, in this paper, a mathematical model that describes a tritrophic Leslie-Gower food-web system is formulated. Sokol-Howell type of function response is adapted to describe the predation process due to the prey’s group defensive capability. The effects of fear due to the predation process are considered in the first two levels. It is assumed that the generalist predator grows logistically using the Leslie-Gower type of growth function. All the solution properties of the model are studied. Local dynamics behaviors are investigated. The basin of attraction for each equilibrium is determined using the Lyapunov function. The conditions of persistence of the model are specified. The study of local bifurcation in the model is done. Numerical simulations are implemented to show the obtained results. It is watched that the system is wealthy in its dynamics including chaos. The fear factor works as a stabilizing factor in the system up to a specific level; otherwise, it leads to the extinction of the predator. However, increasing the prey’s group defense leads to extinction in predator species.

scholarly journals KEYLINK: towards a more integrative soil representation for inclusion in ecosystem scale models. I. review and model concept

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9750
Author(s):  
Gaby Deckmyn ◽  
Omar Flores ◽  
Mathias Mayer ◽  
Xavier Domene ◽  
Andrea Schnepf ◽  
...  
Keyword(s):  
Food Web ◽  
Soil Structure ◽  
Soil Food Web ◽  
Ecosystem Models ◽  
Model Concept ◽  
Soil Functioning ◽  
Scale Models ◽  
Key Issues ◽  
Below Ground ◽  
The Impact

The relatively poor simulation of the below-ground processes is a severe drawback for many ecosystem models, especially when predicting responses to climate change and management. For a meaningful estimation of ecosystem production and the cycling of water, energy, nutrients and carbon, the integration of soil processes and the exchanges at the surface is crucial. It is increasingly recognized that soil biota play an important role in soil organic carbon and nutrient cycling, shaping soil structure and hydrological properties through their activity, and in water and nutrient uptake by plants through mycorrhizal processes. In this article, we review the main soil biological actors (microbiota, fauna and roots) and their effects on soil functioning. We review to what extent they have been included in soil models and propose which of them could be included in ecosystem models. We show that the model representation of the soil food web, the impact of soil ecosystem engineers on soil structure and the related effects on hydrology and soil organic matter (SOM) stabilization are key issues in improving ecosystem-scale soil representation in models. Finally, we describe a new core model concept (KEYLINK) that integrates insights from SOM models, structural models and food web models to simulate the living soil at an ecosystem scale.

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