Experimental evidence for a hidden network of higher-order interactions in a diverse arthropod community

Milton Barbosa; Geraldo Wilson Fernandes; Rebecca Jane Morris

doi:10.1016/j.cub.2022.11.057

Experimental evidence for a hidden network of higher-order interactions in a diverse arthropod community

Curr Biol. 2023 Jan 23;33(2):381-388.e4. doi: 10.1016/j.cub.2022.11.057. Epub 2022 Dec 22.

Authors

Milton Barbosa¹, Geraldo Wilson Fernandes², Rebecca Jane Morris³

Affiliations

¹ Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK; Department of Genetics, Ecology and Evolution, Federal University of Minas Gerais, CP 486, 30161-970 Belo Horizonte, Brazil. Electronic address: miltonbsjunior@ufmg.br.
² Department of Genetics, Ecology and Evolution, Federal University of Minas Gerais, CP 486, 30161-970 Belo Horizonte, Brazil.
³ Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK; School of Biological Sciences, University of Southampton, Highfield Campus, Life Sciences Building 85, Southampton SO17 1BJ, UK.

PMID: 36563693
DOI: 10.1016/j.cub.2022.11.057

Abstract

Transcending pairwise interactions in ecological networks remains a challenge.¹^,²^,³^,⁴^,⁵ Higher-order interactions (HOIs), the modulation of a pairwise interaction by a third species,⁶ are thought to play a particularly important role in stabilizing coexistence and maintaining species diversity.⁷^,⁸^,⁹^,¹⁰^,¹¹^,¹² However, HOIs have so far only been demonstrated in models⁹^,¹⁰^,¹¹^,¹²^,¹³^,¹⁴ or isolated experimental systems including only a few interacting species.⁷^,⁸^,¹⁵ Their ubiquity and importance at a community level in the real world remain unknown. We hypothesized that a complex network of HOIs could be constantly modifying pairwise interactions and shaping ecological communities and that consequently the outcome of pairwise interactions would be a product of many influences from distinct sources. Using field experiments, we tested how multiple interactions within a diverse arthropod community associated with the tropical shrub Baccharis dracunculifolia D.C. (Asteraceae) were modified by the removal of ant species or live or hatched insect galls (a non-trophic engineering effect) of the dominant galler species. We revealed an extensive hidden network of HOIs modifying each other and the "visible" pairwise interactions. Most pairwise interactions were affected indirectly by the manipulation of non-interacting taxonomic groups. The pervasiveness of these interaction modifications challenges pairwise approaches to understanding interaction outcomes and could shift our thinking about the structure and persistence of ecological communities. Investigating coexistence mechanisms involving interaction modulation by HOIs may be key to elucidating the underlying causes of the stability and persistence of ecological communities.

Keywords: Baccharis dracunculifolia; Cerrado; ants; aphids; experimental manipulation; galling insects; indirect interactions; interaction modification; parasitism; parasitoid wasps.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Arthropods*
Baccharis*
Biota
Insecta