The effects of mixotrophy on the stability and dynamics of a simple planktonic food web

Theoretical Population Biology
By: , and 



Recognition of the microbial loop as an important part of aquatic ecosystems disrupted the notion of simple linear food chains. However, current research suggests that even the microbial loop paradigm is a gross simplification of microbial interactions due to the presence of mixotrophs—organisms that both photosynthesize and graze. We present a simple food web model with four trophic species, three of them arranged in a food chain (nutrients–autotrophs–herbivores) and the fourth as a mixotroph with links to both the nutrients and the autotrophs. This model is used to study the general implications of inclusion of the mixotrophic link in microbial food webs and the specific predictions for a parameterization that describes open ocean mixed layer plankton dynamics. The analysis indicates that the system parameters reside in a region of the parameter space where the dynamics converge to a stable equilibrium rather than displaying periodic or chaotic solutions. However, convergence requires weeks to months, suggesting that the system would never reach equilibrium in the ocean due to alteration of the physical forcing regime. Most importantly, the mixotrophic grazing link seems to stabilize the system in this region of the parameter space, particularly when nutrient recycling feedback loops are included.

Publication type Article
Publication Subtype Journal Article
Title The effects of mixotrophy on the stability and dynamics of a simple planktonic food web
Series title Theoretical Population Biology
DOI 10.1016/j.tpb.2004.02.001
Volume 66
Issue 1
Year Published 2004
Language English
Publisher Elsevier
Contributing office(s) Southeast Ecological Science Center
Description 15 p.
First page 37
Last page 51
Online Only (Y/N) N
Additional Online Files (Y/N) N
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