Oecologia

, Volume 174, Issue 3, pp 953–965

Complex life cycles in a pond food web: effects of life stage structure and parasites on network properties, trophic positions and the fit of a probabilistic niche model

  • Daniel L. Preston
  • Abigail Z. Jacobs
  • Sarah A. Orlofske
  • Pieter T. J. Johnson
Community ecology - Original research

DOI: 10.1007/s00442-013-2806-5

Cite this article as:
Preston, D.L., Jacobs, A.Z., Orlofske, S.A. et al. Oecologia (2014) 174: 953. doi:10.1007/s00442-013-2806-5

Abstract

Most food webs use taxonomic or trophic species as building blocks, thereby collapsing variability in feeding linkages that occurs during the growth and development of individuals. This issue is particularly relevant to integrating parasites into food webs because parasites often undergo extreme ontogenetic niche shifts. Here, we used three versions of a freshwater pond food web with varying levels of node resolution (from taxonomic species to life stages) to examine how complex life cycles and parasites alter web properties, the perceived trophic position of organisms, and the fit of a probabilistic niche model. Consistent with prior studies, parasites increased most measures of web complexity in the taxonomic species web; however, when nodes were disaggregated into life stages, the effects of parasites on several network properties (e.g., connectance and nestedness) were reversed, due in part to the lower trophic generality of parasite life stages relative to free-living life stages. Disaggregation also reduced the trophic level of organisms with either complex or direct life cycles and was particularly useful when including predation on parasites, which can inflate trophic positions when life stages are collapsed. Contrary to predictions, disaggregation decreased network intervality and did not enhance the fit of a probabilistic niche model to the food webs with parasites. Although the most useful level of biological organization in food webs will vary with the questions of interest, our results suggest that disaggregating species-level nodes may refine our perception of how parasites and other complex life cycle organisms influence ecological networks.

Keywords

Community ecology Wetland Food web model Topology Host–parasite interaction 

Supplementary material

442_2013_2806_MOESM1_ESM.docx (18 kb)
Supplementary material 1 (DOCX 117 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Daniel L. Preston
    • 1
  • Abigail Z. Jacobs
    • 2
  • Sarah A. Orlofske
    • 3
  • Pieter T. J. Johnson
    • 1
  1. 1.Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderUSA
  2. 2.Department of Computer ScienceUniversity of ColoradoBoulderUSA
  3. 3.Department of BiologyNortheastern Illinois UniversityChicagoUSA

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