The origin of motif families in food webs

Research output: Contribution to journalArticle

Authors

Colleges, School and Institutes

External organisations

  • Centre for Complexity Science, University of Warwick

Abstract

Food webs have been found to exhibit remarkable “motif profles”, patterns in the relative prevalences of all possible three-species subgraphs, and this has been related to ecosystem properties such as stability and robustness. Analysing 46 food webs of various kinds, we fnd that most food webs fall into one of two distinct motif families. The separation between the families is well predicted by a global measure of hierarchical order in directed networks—trophic coherence. We fnd that trophic coherence is also a good predictor for the extent of omnivory, defned as the tendency of species to feed on multiple trophic levels. We compare our results to a network assembly model that admits
tunable trophic coherence via a single free parameter. The model is able to generate food webs in either of the two families by varying this parameter, and correctly classifes almost all the food webs in our database. This is in contrast with the two most popular food web models, the generalized cascade and niche models, which can only generate food webs within a single motif family. Our fndings suggest the importance of trophic coherence in modelling local preying patterns in food webs.

Details

Original languageEnglish
Article number16197
Number of pages11
JournalScientific Reports
Publication statusPublished - 23 Nov 2017