scholarly journals Intrapopulation niche partitioning in a generalist predator limits food web connectivity

Ecology ◽  
2009 ◽  
Vol 90 (8) ◽  
pp. 2263-2274 ◽  
Author(s):  
Mario Quevedo ◽  
Richard Svanbäck ◽  
Peter Eklöv
Keyword(s):  
Food Web ◽  
Niche Partitioning ◽  
Generalist Predator

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 DNA metabarcoding reveals trophic niche diversity of micro and mesozooplankton species

2021 ◽  
Vol 288 (1953) ◽  
pp. 20210908
Author(s):  
Andreas Novotny ◽  
Sara Zamora-Terol ◽  
Monika Winder
Keyword(s):  
Energy Transfer ◽  
Food Web ◽  
Resource Use ◽  
Niche Partitioning ◽  
Trophic Niche ◽  
Alternative Pathways ◽  
Wide Range ◽  
Dna Metabarcoding ◽  
The Baltic ◽  
Species Specific

Alternative pathways of energy transfer guarantee the functionality and productivity in marine food webs that experience strong seasonality. Nevertheless, the complexity of zooplankton interactions is rarely considered in trophic studies because of the lack of detailed information about feeding interactions in nature. In this study, we used DNA metabarcoding to highlight the diversity of trophic niches in a wide range of micro- and mesozooplankton, including ciliates, rotifers, cladocerans, copepods and their prey, by sequencing 16- and 18S rRNA genes. Our study demonstrates that the zooplankton trophic niche partitioning goes beyond both phylogeny and size and reinforces the importance of diversity in resource use for stabilizing food web efficiency by allowing for several different pathways of energy transfer. We further highlight that small, rarely studied zooplankton (rotifers and ciliates) fill an important role in the Baltic Sea pelagic primary production pathways and the potential of ciliates, rotifers and crustaceans in the utilization of filamentous and picocyanobacteria within the pelagic food web. The approach used in this study is a suitable entry point to ecosystem-wide food web modelling considering species-specific resource use of key consumers.

On a Food Web Consisting of a Specialist and a Generalist Predator

2003 ◽  
Vol 11 (04) ◽  
pp. 365-376 ◽  
Author(s):  
S. Gakkhar ◽  
R. K. Naji
Keyword(s):  
Food Web ◽  
Continuous Time ◽  
Chaotic Behavior ◽  
Generalist Predator ◽  
Continuous Time Model ◽  
Time Model ◽  
Interacting Populations ◽  
Necessary And Sufficient Criteria ◽  
Coexisting Species ◽  
Necessary And Sufficient

A biologically feasible continuous time model of a three level food web consisting of a specialist and a generalist predator is investigated. The boundedness of the unique solution of the model establishes the dissipative nature of the food web. Necessary and sufficient criteria for the coexistence of the three interacting populations are established. Complex behavior of the system is evident from the bifurcation diagrams. Abundance of periodic and chaotic behavior of the species with the variation of the key parameters are also observed. The strange attractors for the time evolution of the coexisting species are drawn.

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