Habitat heterogeneity induces rapid changes in the feeding behaviour of generalist arthropod predators

Research output: Contribution to journalArticle

Abstract

The "habitat heterogeneity hypothesis" predicts positive effects of structural complexity on species coexistence. Increasing habitat heterogeneity can change the diversity (number of species, abundances) and the functional roles of communities. The latter, however, is not well understood as species and individuals may respond very differently and dynamically to a changing environment. Here, we experimentally test how habitat heterogeneity affects generalist arthropod predators, including epigaeic spiders, carabid and staphylinid beetles, under natural conditions by assessing their diversity and directly measuring their trophic interactions (which provide a proxy for their functional roles). The experiment was conducted in spring barley fields in Southern Sweden where habitat heterogeneity was manipulated by increasing within-field plant diversity. Increased habitat heterogeneity triggered rapid changes in the feeding behaviour of generalist predators characterized by lower trophic specialization at both network (H2', degree of interaction specialization in the entire network) and species level (d', degree of interaction specialization at the species level). We presume that this is because spatial separation resulted in relaxed competition and allowed an increased overlap in resources used among predator species. Predators collected from heterogenous habitats also showed greater individual-level dietary variability which might be ascribed to relaxed intraspecific competition. Our results provide conclusive evidence that habitat heterogeneity can induce rapid behavioural responses independent of changes in diversity, potentially promoting the stability of ecosystem functions. A plain language summary is available for this article.

Details

Authors
  • Karin Staudacher
  • Oskar Rennstam Rubbmark
  • Klaus Birkhofer
  • Gerard Malsher
  • Daniela Sint
  • Mattias Jonsson
  • Michael Traugott
Organisations
External organisations
  • University of Innsbruck
  • Brandenburg University of Technology Cottbus- Senftenberg
  • Swedish University of Agricultural Sciences
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Ecology

Keywords

  • Food webs, Habitat complexity, Habitat microstructure, Molecular diet analysis, Specialization index, Trophic interactions
Original languageEnglish
Pages (from-to)809-819
JournalFunctional Ecology
Volume32
Issue number3
Early online date2018 Jan 10
Publication statusPublished - 2018 Mar
Publication categoryResearch
Peer-reviewedYes