Weak predation strength promotes stable coexistence of predators and prey in the same chain and across chains

AbstractThe mechanisms of species coexistence make ecologists fascinated, although theoretical work show that omnivory can promote coexistence of species and food web stability, it is still a lack of the general mechanisms for species coexistence in the real food webs, and is unknown how omnivory affects the interactions between competitor and predator. In this work, we first establish an omnivorous food web model with a competitor based on two natural ecosystems (the plankton community and fig-fig wasp system). We analyze the changes of both food web structure and stability under the different resource levels and predation preference of the generalist/top predator. The results of model analyses show that weak predation strength can promote stable coexistence of predators and prey. Moreover, evolutionary trend of food web structure changes with the relative predation strength is more diversity than the relative competition strength, and an integration of both omnivory, increased competition, top-down control and bottom-up control can promote species diversity and food web stability. Our theoretical predictions are consistent with empirical data in the plankton community: the lower concentration of nutrient results in a more stable population dynamics. Our theoretical work could enrich the general omnivorous theory on species coexistence and system stability in the real food webs.

Download Full-text

Weak Predation Strength Promotes Stable Coexistence of Predators and Prey in the Same Chain and Across Chains

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127420502284 ◽

2020 ◽

Vol 30 (15) ◽

pp. 2050228

Author(s):

Lin Wang ◽

Yan-Ping Liu ◽

Rui-Wu Wang

Keyword(s):

Food Web ◽

Food Webs ◽

Species Coexistence ◽

Theoretical Work ◽

Plankton Community ◽

System Stability ◽

Food Web Structure ◽

The Real ◽

Stable Coexistence ◽

Web Structure

The mechanisms of species coexistence make ecologists fascinated, although theoretical work shows that omnivory can promote coexistence of species and food web stability, it is still a lack of the general mechanisms for species coexistence in the real food webs, and is unknown how omnivory affects the interactions between competitor and predator. In this work, we first establish an omnivorous food web model with a competitor based on two natural ecosystems (the plankton community and fig–fig wasp system). We analyze the changes of both food web structure and stability under the different resource levels and predation preference of the generalist/top predator. The results of model analyses show that weak predation strength can promote stable coexistence of predators and prey. Moreover, the evolutionary trend of food web structure changes with the relative predation strength is more diverse than the relative competition strength, and an integration of both omnivory, increased competition, top-down control and bottom-up control can promote species diversity and food web stability. Our theoretical predictions are consistent with empirical data in the plankton community: the lower concentration of nutrient results in a more stable population dynamics. Our theoretical work could enrich the general omnivorous theory on species coexistence and system stability in the real food webs.

Download Full-text

Decrease in diatom dominance at lower Si:N ratios alters plankton food webs

Journal of Plankton Research ◽

10.1093/plankt/fbaa032 ◽

2020 ◽

Vol 42 (4) ◽

pp. 411-424

Author(s):

Kriste Makareviciute-Fichtner ◽

Birte Matthiessen ◽

Heike K Lotze ◽

Ulrich Sommer

Keyword(s):

Food Web ◽

Food Webs ◽

Phytoplankton Community ◽

Plankton Community ◽

Trophic Levels ◽

Food Web Structure ◽

Planktonic Food ◽

Web Structure ◽

Copepod Grazing ◽

Important Food Source

Abstract Many coastal oceans experience not only increased loads of nutrients but also changes in the stoichiometry of nutrient supply. Excess supply of nitrogen and stable or decreased supply of silicon lower silicon to nitrogen (Si:N) ratios, which may decrease diatom proportion in phytoplankton. To examine how Si:N ratios affect plankton community composition and food web structure, we performed a mesocosm experiment where we manipulated Si:N ratios and copepod abundance in a Baltic Sea plankton community. In high Si:N treatments, diatoms dominated. Some of them were likely spared from grazing unexpectedly resulting in higher diatom biomass under high copepod grazing. With declining Si:N ratios, dinoflagellates became more abundant under low and picoplankton under high copepod grazing. This altered plankton food web structure: under high Si:N ratios, edible diatoms were directly accessible food for copepods, while under low Si:N ratios, microzooplankton and phago-mixotrophs (mixoplankton) were a more important food source for mesograzers. The response of copepods to changes in the phytoplankton community was complex and copepod density-dependent. We suggest that declining Si:N ratios favor microzoo- and mixoplankton leading to increased complexity of planktonic food webs. Consequences on higher trophic levels will, however, likely be moderated by edibility, nutritional value or toxicity of dominant phytoplankton species.

Download Full-text

The more food webs change, the more they stay the same

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2008.0273 ◽

2009 ◽

Vol 364 (1524) ◽

pp. 1789-1801 ◽

Cited By ~ 84

Author(s):

Kevin Shear McCann ◽

Neil Rooney

Keyword(s):

Food Web ◽

Food Webs ◽

Temporal Variability ◽

Spatial And Temporal Variability ◽

Scale Invariant ◽

Food Web Structure ◽

Behavioural Responses ◽

Web Structure ◽

Food Web Ecology ◽

Food Web Theory

Here, we synthesize a number of recent empirical and theoretical papers to argue that food-web dynamics are characterized by high amounts of spatial and temporal variability and that organisms respond predictably, via behaviour, to these changing conditions. Such behavioural responses on the landscape drive a highly adaptive food-web structure in space and time. Empirical evidence suggests that underlying attributes of food webs are potentially scale-invariant such that food webs are characterized by hump-shaped trophic structures with fast and slow pathways that repeat at different resolutions within the food web. We place these empirical patterns within the context of recent food-web theory to show that adaptable food-web structure confers stability to an assemblage of interacting organisms in a variable world. Finally, we show that recent food-web analyses agree with two of the major predictions of this theory. We argue that the next major frontier in food-web theory and applied food-web ecology must consider the influence of variability on food-web structure.

Download Full-text

The use of DNA barcodes in food web construction—terrestrial and aquatic ecologists unite!

Genome ◽

10.1139/gen-2015-0229 ◽

2016 ◽

Vol 59 (9) ◽

pp. 603-628 ◽

Cited By ~ 47

Author(s):

Tomas Roslin ◽

Sanna Majaneva

Keyword(s):

Food Web ◽

Food Webs ◽

Taxonomic Resolution ◽

Dna Barcodes ◽

Food Web Structure ◽

Web Studies ◽

Web Structure ◽

Asking Questions ◽

Web Construction ◽

Interaction Webs

By depicting who eats whom, food webs offer descriptions of how groupings in nature (typically species or populations) are linked to each other. For asking questions on how food webs are built and work, we need descriptions of food webs at different levels of resolution. DNA techniques provide opportunities for highly resolved webs. In this paper, we offer an exposé of how DNA-based techniques, and DNA barcodes in particular, have recently been used to construct food web structure in both terrestrial and aquatic systems. We highlight how such techniques can be applied to simultaneously improve the taxonomic resolution of the nodes of the web (i.e., the species), and the links between them (i.e., who eats whom). We end by proposing how DNA barcodes and DNA information may allow new approaches to the construction of larger interaction webs, and overcome some hurdles to achieving adequate sample size. Most importantly, we propose that the joint adoption and development of these techniques may serve to unite approaches to food web studies in aquatic and terrestrial systems—revealing the extent to which food webs in these environments are structured similarly to or differently from each other, and how they are linked by dispersal.

Download Full-text

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

10.1101/019497 ◽

2015 ◽

Cited By ~ 1

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.

Download Full-text

Surface water connectivity controls fish food web structure and complexity across local- and meta-food webs in Arctic Coastal Plain lakes

Food Webs ◽

10.1016/j.fooweb.2019.e00123 ◽

2019 ◽

Vol 21 ◽

pp. e00123 ◽

Cited By ~ 1

Author(s):

Sarah M. Laske ◽

Amanda E. Rosenberger ◽

Mark S. Wipfli ◽

Christian E. Zimmerman

Keyword(s):

Surface Water ◽

Food Web ◽

Food Webs ◽

Coastal Plain ◽

Food Web Structure ◽

Fish Food ◽

Web Structure ◽

Arctic Coastal Plain

Download Full-text

Resolving Food-Web Structure

Annual Review of Ecology Evolution and Systematics ◽

10.1146/annurev-ecolsys-110218-024908 ◽

2020 ◽

Vol 51 (1) ◽

pp. 55-80

Author(s):

Robert M. Pringle ◽

Matthew C. Hutchinson

Keyword(s):

Food Web ◽

Food Webs ◽

Trophic Interactions ◽

Sampling Methods ◽

Taxonomic Resolution ◽

Major Focus ◽

Web Data ◽

Food Web Structure ◽

Web Structure ◽

Abundant Evidence

Food webs are a major focus and organizing theme of ecology, but the data used to assemble them are deficient. Early debates over food-web data focused on taxonomic resolution and completeness, lack of which had produced spurious inferences. Recent data are widely believed to be much better and are used extensively in theoretical and meta-analytic research on network ecology. Confidence in these data rests on the assumptions ( a) that empiricists correctly identified consumers and their foods and ( b) that sampling methods were adequate to detect a near-comprehensive fraction of the trophic interactions between species. Abundant evidence indicates that these assumptions are often invalid, suggesting that most topological food-web data may remain unreliable for inferences about network structure and underlying ecological and evolutionary processes. Morphologically cryptic species are ubiquitous across taxa and regions, and many trophic interactions routinely evade detection by conventional methods. Molecular methods have diagnosed the severity of these problems and are a necessary part of the cure.

Download Full-text