title: The value of trophic interactions for ecosystem function: dung beetle communities influence seed burial and seedling recruitment in tropical forests.
abstract: Anthropogenic activities are causing species extinctions, raising concerns about the consequences of changing biological communities for ecosystem functioning. To address this, we investigated how dung beetle communities influence seed burial and seedling recruitment in the Brazilian Amazon. First, we conducted a burial and retrieval experiment using seed mimics. We found that dung beetle biomass had a stronger positive effect on the burial of large than small beads, suggesting that anthropogenic reductions in large-bodied beetles will have the greatest effect on the secondary dispersal of large-seeded plant species. Second, we established mesocosm experiments in which dung beetle communities buried Myrciaria dubia seeds to examine plant emergence and survival. Contrary to expectations, we found that beetle diversity and biomass negatively influenced seedling emergence, but positively affected the survival of seedlings that emerged. Finally, we conducted germination trials to establish the optimum burial depth of experimental seeds, revealing a negative relationship between burial depth and seedling emergence success. Our results provide novel evidence that seed burial by dung beetles may be detrimental for the emergence of some seed species. However, we also detected positive impacts of beetle activity on seedling recruitment, which are probably because of their influence on soil properties. Overall, this study provides new evidence that anthropogenic impacts on dung beetle communities could influence the structure of tropical forests; in particular, their capacity to regenerate and continue to provide valuable functions and services.
authors.affiliation: Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ, UK han.m.griffiths@gmail.com.|Departamento de Biologia, Universidade Federal de Lavras, Lavras, Minas Gerais 37200-000, Brazil.|School of Environmental Sciences, The University of Liverpool, Nicholson Building, L69 3GP, UK.
authors.forename: Hannah M
authors.identifier: 0000-0002-4800-8031
authors.initials: HM
authors.lastname: Griffiths
authors.affiliation: School of Earth and Environmental Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Bardgett
authors.affiliation: Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ, UK.|Departamento de Biologia, Universidade Federal de Lavras, Lavras, Minas Gerais 37200-000, Brazil.
authors.forename: Julio
authors.initials: J
authors.lastname: Louzada
authors.affiliation: Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ, UK.|Departamento de Biologia, Universidade Federal de Lavras, Lavras, Minas Gerais 37200-000, Brazil.|Museu Paraense Emilio Goeldi, Av. Magalhães Barata, 376, Belém, Pará, Brazil.
authors.forename: Jos
authors.initials: J
authors.lastname: Barlow
mesh_terms: D000818:Animals; D001938:Brazil; D001517:Coleoptera; D065928:Forests; D058614:Seed Dispersal; D036226:Seedlings / Q000254:growth & development*; D012639:Seeds
keywords: biodiversity–ecosystem functioning; defaunation; ecosystem processes; plant recruitment; soil