Diversity begets diversity in competition for space

TY - JOUR

T1 - Diversity begets diversity in competition for space

AU - Maynard, Daniel S.

AU - Bradford, Mark A.

AU - Lindner, Daniel L.

AU - van Diepen, Linda T. A.

AU - Frey, Serita D.

AU - Glaeser, Jessie A.

AU - Crowther, Thomas W.

N1 - 6394, TE; Data archiving: data archived at Github

PY - 2017/5/15

Y1 - 2017/5/15

N2 - Competition can profoundly affect biodiversity patterns by determining whether similar species are likely to coexist. When speciescompete directly for space, competitive ability differences should theoretically promote trait and phylogenetic clustering,provided that niche differences are otherwise minimal. Yet many sessile communities exhibit high biodiversity despite minimalreliance on niche differentiation. A potential explanation is that intransitive competition (‘rock–paper–scissors’ competition)not only promotes species richness but also fosters coexistence among highly dissimilar species with different competitivestrategies. Here, we test this hypothesis using a combination of empirical and analytical approaches. In an experimental systemcomprising 37 wood-decay basidiomycete fungi grown in nutrient-rich agar media, pairwise displacement was maximized whenspecies had widely different competitive traits and divergent evolutionary histories. However, when these interactions wereembedded in models of species-rich communities, high levels of intransitivity ultimately overwhelmed the pairwise relationships,allowing the weakest and most dissimilar species to survive. In line with theoretical expectations, these multispeciesassemblages exhibited reduced functional and phylogenetic diversity, yet the smallest losses were likewise observed in species-rich communities. By demonstrating that species richness can act as a self-reinforcing buffer against competitive exclusion,these results contribute to our understanding of how biodiversity is maintained in natural systems.

AB - Competition can profoundly affect biodiversity patterns by determining whether similar species are likely to coexist. When speciescompete directly for space, competitive ability differences should theoretically promote trait and phylogenetic clustering,provided that niche differences are otherwise minimal. Yet many sessile communities exhibit high biodiversity despite minimalreliance on niche differentiation. A potential explanation is that intransitive competition (‘rock–paper–scissors’ competition)not only promotes species richness but also fosters coexistence among highly dissimilar species with different competitivestrategies. Here, we test this hypothesis using a combination of empirical and analytical approaches. In an experimental systemcomprising 37 wood-decay basidiomycete fungi grown in nutrient-rich agar media, pairwise displacement was maximized whenspecies had widely different competitive traits and divergent evolutionary histories. However, when these interactions wereembedded in models of species-rich communities, high levels of intransitivity ultimately overwhelmed the pairwise relationships,allowing the weakest and most dissimilar species to survive. In line with theoretical expectations, these multispeciesassemblages exhibited reduced functional and phylogenetic diversity, yet the smallest losses were likewise observed in species-rich communities. By demonstrating that species richness can act as a self-reinforcing buffer against competitive exclusion,these results contribute to our understanding of how biodiversity is maintained in natural systems.

KW - international

UR - https://github.com/dsmaynard/diversity_begets_diversity

U2 - 10.1038/s41559-017-0156

DO - 10.1038/s41559-017-0156

M3 - Article

SN - 2397-334X

VL - 1

JO - Nature Ecology and Evolution

JF - Nature Ecology and Evolution

M1 - 0156

ER -