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 The effect of resource dynamics on species packing in diverse ecosystems

2019 ◽  
Author(s):  
Wenping Cui ◽  
Robert Marsland ◽  
Pankaj Mehta
Keyword(s):  
Competitive Exclusion ◽  
Exclusion Principle ◽  
Ecological Niches ◽  
Resource Model ◽  
Competitive Exclusion Principle ◽  
Species Packing ◽  
Resource Dynamics ◽  
Coexisting Species ◽  
Open Question ◽  
Consumer Resource

The competitive exclusion principle asserts that coexisting species must occupy distinct ecological niches (i.e. the number of surviving species can not exceed the number of resources). An open question is to understand if and how different resource dynamics affect this bound. Here, we analyze a generalized consumer resource model with externally supplied resources and show that – in contrast to self-renewing resources – species can occupy only half of all available environmental niches. This motivates us to construct a new schema for classifying ecosystems based on species packing properties.

scholarly journals Bridging fisheries management and biodiversity conservation norms: potential and challenges of balancing harvest in ecosystem-based frameworks

2015 ◽  
Vol 73 (6) ◽  
pp. 1659-1667 ◽  
Author(s):  
S. M. Garcia ◽  
J. Rice ◽  
A. Charles
Keyword(s):  
Decision Making ◽  
Fisheries Management ◽  
Biological Diversity ◽  
Population Level ◽  
System Level ◽  
Convention On Biological Diversity ◽  
Management Decision ◽  
Size Spectrum ◽  
Ecosystem Structure ◽  
Management Decision Making

Abstract Balanced harvesting has been proposed as a way for fisheries management to achieve the requirements of both the Law of the Sea Convention (LOSC)—to maintain stocks at the level at which they could produce MSY—and the Convention on Biological Diversity (CBD)—to maintain ecosystem structure and functioning. This paper examines these requirements and briefly presents four system-level relationships (spectra), representing ecosystem structures that might guide management decision-making aiming to meet both requirements. These spectra would fit in the widely accepted frameworks of the Ecosystem Approach enshrined in the CBD and adopted by FAO for Fisheries. A size spectrum, relating biomass to body length, is used as an example to illustrate its potential to support management decision-making—much like present stock-based harvest control rules—in more ecosystem-compliant fishing strategies at a sector or ecosystem level, as a complement to those currently used at a stock/population level.

Dynamics of Consumer-Resource Systems

2013 ◽  
Author(s):  
André M. de Roos ◽  
Lennart Persson
Keyword(s):  
Model Organism ◽  
Growth Dynamics ◽  
Population Cycles ◽  
Food Density ◽  
Juvenile Period ◽  
Ecological Processes ◽  
Resource Dynamics ◽  
Cladoceran Zooplankton ◽  
The Individual ◽  
Consumer Resource

This chapter focuses on consumer-resource dynamics in systems where consumers of different sizes compete for a shared resource. It considers the implications of three important aspects of consumer life history: the explicit handling of a juvenile period leading to a delay between the time when an individual is born to when it starts to reproduce; the rate by which individual ecological processes scale with body size; and whether the rate by which the individual grows is dependent on food density or not. The chapter examines the effects of different resource growth dynamics to illustrate the fundamental differences between population cycles driven by interactions between individuals of different sizes, and classical predator–prey cycles driven by interactions between the consumer and the resource, also referred to as paradox of enrichment cycles. It also discusses experiments with the model organism, the cladoceran zooplankton Daphnia, to elucidate our current understanding of cycles driven by cohort interactions in this organism.

Consumer–resource dynamics in Arctic ponds

Ecology ◽  
2020 ◽  
Vol 101 (10) ◽  
Author(s):  
Melissa H. DeSiervo ◽  
Matthew P. Ayres ◽  
Ross A. Virginia ◽  
Lauren E. Culler
Keyword(s):  
Arctic Ponds ◽  
Resource Dynamics ◽  
Consumer Resource
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