UNDERSTANDING MULTIPLE SPECIES ECOSYSTEM DYNAMICS USING A CONSUMER RESOURCE MODEL

2016 ◽  
Vol 29 (1) ◽  
pp. 145-158
Author(s):  
OBIORA C. COLLINS ◽  
KEVIN J. DUFFY
Keyword(s):  
Ecosystem Dynamics ◽  
Resource Model ◽  
Multiple Species ◽  
Consumer Resource

scholarly journals Linking Fishing Behavior and Ecosystem Dynamics Using Social and Ecological Network Models

2021 ◽  
Vol 9 ◽  
Author(s):  
Joseph J. Luczkovich ◽  
Jeffrey C. Johnson ◽  
Rebecca A. Deehr ◽  
Kevin J. Hart ◽  
Lisa Clough ◽  
...  
Keyword(s):  
Fishery Management ◽  
Fishing Effort ◽  
Ecosystem Dynamics ◽  
Ecological System ◽  
Regulatory Change ◽  
Estuarine Ecosystem ◽  
Gill Net ◽  
Affiliation Network ◽  
Multiple Species ◽  
Fishing Behavior

One goal of ecosystem-based management is studying an ecosystem and its people, the socio-ecological system, in a qualitative and quantitative modeling approach that can provide management agencies with possible outcomes of their actions using scenario forecasting. Ecosystem-based fisheries management strives to use the socio-ecological system approach, including direct and indirect impacts on multiple species including the behavioral responses of fishers after a regulatory change (a gillnet ban). Here, we link fisher behavioral networks with a mass-balanced food-web ECOPATH network model of an estuarine ecosystem and its commercial fisheries for an analysis of fishing impacts after a gillnet ban on multiple species using ECOSIM. We modeled fisher behavioral networks using reported catches of species from individual fishers along with the gear fished to create nodes in a gear/species affiliation network. Individual fishers with common gear/species use are indicative of common fishing behavior. When such fishers have high network centrality and are engaged in multiple gear/species fisheries, they can transition to other gear/species fisheries along “switching pathways” when facing a regulatory change. We used an index of joint gear participation to identify likely gear switching pathways, and we predicted changes in fishing effort after a gill net ban. We simulated the gill net ban in ECOSIM under two scenarios of fishing effort: Scenario 1, gill net fishing effort of 0%; Scenario 2, gill net fishing effort of 0% with increased effort in the alternative gear fisheries using the predicted switching pathways for the affiliation network. Scenario 1 predicted an increase in flounder (Paralichthys spp.) biomass over a decade. Under Scenario 2, fishers targeting flounders were predicted to switch from gill nets to pound nets. Scenario 2 predicted a 7% decline in flounder biomass over ten years, rather than an increase in flounders. The gillnet ban with increased effort due to switching is predicted to have the opposite effect on the conservation goal, which was to increase flounder stocks. Fishery management that incorporates a socio-ecological approach modeling both fisher behaviors and multi-species ecosystem responses can reveal single-species responses that are in the opposite direction of the anticipated management goals.

scholarly journals Asymptotical behaviors of a general diffusive consumer-resource model with maturation delay

2015 ◽  
Vol 20 (6) ◽  
pp. 1715-1733 ◽  
Author(s):  
Wonlyul Ko ◽  
◽  
Inkyung Ahn ◽  
Shengqiang Liu ◽  
Keyword(s):  
Resource Model ◽  
Maturation Delay ◽  
Consumer Resource

scholarly journals Computational Study on the Dynamics of a Consumer-Resource Model: The Influence of the Growth Law in the Resource

Mathematics ◽  
2021 ◽  
Vol 9 (21) ◽  
pp. 2746
Author(s):  
Luis M. Abia ◽  
Óscar Angulo ◽  
Juan Carlos López-Marcos ◽  
Miguel Ángel López-Marcos
Keyword(s):  
Numerical Study ◽  
Computational Study ◽  
Point Of View ◽  
Global Dynamics ◽  
Resource Model ◽  
Resource Population ◽  
Consumer Population ◽  
Order Scheme ◽  
Growth Laws ◽  
Consumer Resource

The dynamics of a specific consumer-resource model for Daphnia magna is studied from a numerical point of view. In this study, Malthusian, chemostatic, and Gompertz growth laws for the evolution of the resource population are considered, and the resulting global dynamics of the model are compared as different parameters involved in the model change. In the case of Gompertz growth law, a new complex dynamic is found as the carrying capacity for the resource population increases. The numerical study is carried out with a second-order scheme that approximates the size-dependent density function for individuals in the consumer population. The numerical method is well adapted to the situation in which the growth rate for the consumer individuals is allowed to change the sign and, therefore, individuals in the consumer population can shrink in size as time evolves. The numerical simulations confirm that the shortage of the resource has, as a biological consequence, the effective shrink in size of individuals of the consumer population. Moreover, the choice of the growth law for the resource population can be selected by how the dynamics of the populations match with the qualitative behaviour of the data.

Consumer-Resource Dynamics and Emergent Density Dependence

2019 ◽  
pp. 163-182
Author(s):  
Ken H. Andersen
Keyword(s):  
Density Dependence ◽  
Population Size ◽  
Fisheries Management ◽  
Late Life ◽  
Static Model ◽  
Size Spectrum ◽  
Resource Model ◽  
Single Population ◽  
Resource Dynamics ◽  
Consumer Resource

This chapter focuses on a generalization of a classic consumer-resource model with a single population embedded in a community. It develops this physiologically structured consumer-resource model by extending the static model in Chapter 4. The chapter then studies how density dependence emerges in the model, and how it changes the population size spectrum. Finally, the chapter explores how some of the standard fisheries impact assessments from Chapter 5 are changed when density dependence is in the form of competition or cannibalism. Specifically, it shows how the appearance of late-life density dependence rocks one of the cornerstones of contemporary fisheries management: that we should fish only the largest fish. In some cases, it turns out that yield is instead maximized by fishing juveniles.

scholarly journals Inquiline predator increases nutrient-cycling efficiency of Nepenthes rafflesiana pitchers

2019 ◽  
Vol 15 (12) ◽  
pp. 20190691
Author(s):  
Weng Ngai Lam ◽  
Ying Yi Chou ◽  
Felicia Wei Shan Leong ◽  
Hugh Tiang Wah Tan
Keyword(s):  
Experimental Data ◽  
Nutrient Cycling ◽  
Ecosystem Functioning ◽  
Trophic Levels ◽  
Resource Model ◽  
Pitcher Plants ◽  
Predator Prey ◽  
Invertebrate Prey ◽  
Cycling Efficiency ◽  
Consumer Resource

The modified-leaf pitchers of Nepenthes rafflesiana pitcher plants are aquatic, allochthonous ecosystems that are inhabited by specialist inquilines and sustained by the input of invertebrate prey. Detritivorous inquilines are known to increase the nutrient-cycling efficiency (NCE) of pitchers but it is unclear whether predatory inquilines that prey on these detritivores decrease the NCE of pitchers by reducing detritivore populations or increase the NCE of pitchers by processing nutrients that may otherwise be locked up in detritivore biomass. Nepenthosyrphus is a small and poorly studied genus of hoverflies and the larvae of one such species is a facultatively detritivorous predator that inhabits the pitchers of N. rafflesiana . We fitted a consumer–resource model to experimental data collected from this system. Simulations showed that systems containing the predator at equilibrium almost always had higher NCEs than those containing only prey (detritivore) species. We showed using a combination of simulated predator/prey exclusions that the processing of the resource through multiple pathways and trophic levels in this system is more efficient than that accomplished through fewer pathways and trophic levels. Our results thus support the vertical diversity hypothesis, which predicts that greater diversity across trophic levels results in greater ecosystem functioning.

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