Parasites Affect Food Web Structure Primarily through Increased Diversity and Complexity

Jennifer A. Dunne, Kevin D. Lafferty, Andrew P. Dobson, Ryan F. Hechinger, Armand M. Kuris, Neo D Martinez, John P. McLaughlin, Kim N. Mouritsen, Robert Poulin, Karsten Reise, Daniel B. Stouffer, David W. Thieltges, Richard J. Williams, Claus Dieter Zander

Research output: Contribution to journalArticle

116 Citations (Scopus)

Abstract

Comparative research on food web structure has revealed generalities in trophic organization, produced simple models, and allowed assessment of robustness to species loss. These studies have mostly focused on free-living species. Recent research has suggested that inclusion of parasites alters structure. We assess whether such changes in network structure result from unique roles and traits of parasites or from changes to diversity and complexity. We analyzed seven highly resolved food webs that include metazoan parasite data. Our analyses show that adding parasites usually increases link density and connectance (simple measures of complexity), particularly when including concomitant links (links from predators to parasites of their prey). However, we clarify prior claims that parasites "dominate" food web links. Although parasites can be involved in a majority of links, in most cases classic predation links outnumber classic parasitism links. Regarding network structure, observed changes in degree distributions, 14 commonly studied metrics, and link probabilities are consistent with scale-dependent changes in structure associated with changes in diversity and complexity. Parasite and free-living species thus have similar effects on these aspects of structure. However, two changes point to unique roles of parasites. First, adding parasites and concomitant links strongly alters the frequency of most motifs of interactions among three taxa, reflecting parasites' roles as resources for predators of their hosts, driven by trophic intimacy with their hosts. Second, compared to free-living consumers, many parasites' feeding niches appear broader and less contiguous, which may reflect complex life cycles and small body sizes. This study provides new insights about generic versus unique impacts of parasites on food web structure, extends the generality of food web theory, gives a more rigorous framework for assessing the impact of any species on trophic organization, identifies limitations of current food web models, and provides direction for future structural and dynamical models.

Original languageEnglish (US)
Article numbere1001579
JournalPLoS Biology
Volume11
Issue number6
DOIs
StatePublished - Jun 2013
Externally publishedYes

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Food Chain
food webs
Parasites
parasites
predators
Structural Models
Body Size
Life Cycle Stages
Research
Life cycle
life cycle (organisms)
parasitism
niches

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)
  • Neuroscience(all)

Cite this

Dunne, J. A., Lafferty, K. D., Dobson, A. P., Hechinger, R. F., Kuris, A. M., Martinez, N. D., ... Zander, C. D. (2013). Parasites Affect Food Web Structure Primarily through Increased Diversity and Complexity. PLoS Biology, 11(6), [e1001579]. https://doi.org/10.1371/journal.pbio.1001579

Parasites Affect Food Web Structure Primarily through Increased Diversity and Complexity. / Dunne, Jennifer A.; Lafferty, Kevin D.; Dobson, Andrew P.; Hechinger, Ryan F.; Kuris, Armand M.; Martinez, Neo D; McLaughlin, John P.; Mouritsen, Kim N.; Poulin, Robert; Reise, Karsten; Stouffer, Daniel B.; Thieltges, David W.; Williams, Richard J.; Zander, Claus Dieter.

In: PLoS Biology, Vol. 11, No. 6, e1001579, 06.2013.

Research output: Contribution to journalArticle

Dunne, JA, Lafferty, KD, Dobson, AP, Hechinger, RF, Kuris, AM, Martinez, ND, McLaughlin, JP, Mouritsen, KN, Poulin, R, Reise, K, Stouffer, DB, Thieltges, DW, Williams, RJ & Zander, CD 2013, 'Parasites Affect Food Web Structure Primarily through Increased Diversity and Complexity', PLoS Biology, vol. 11, no. 6, e1001579. https://doi.org/10.1371/journal.pbio.1001579
Dunne, Jennifer A. ; Lafferty, Kevin D. ; Dobson, Andrew P. ; Hechinger, Ryan F. ; Kuris, Armand M. ; Martinez, Neo D ; McLaughlin, John P. ; Mouritsen, Kim N. ; Poulin, Robert ; Reise, Karsten ; Stouffer, Daniel B. ; Thieltges, David W. ; Williams, Richard J. ; Zander, Claus Dieter. / Parasites Affect Food Web Structure Primarily through Increased Diversity and Complexity. In: PLoS Biology. 2013 ; Vol. 11, No. 6.
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