title: Phylogenetic structure of soil bacterial communities predicts ecosystem functioning.
abstract: Quantifying diversity with phylogeny-informed metrics helps understand the effects of diversity on ecosystem functioning (EF). The sign of these effects remains controversial because phylogenetic diversity and taxonomic identity may interactively influence EF. Positive relationships, traditionally attributed to complementarity effects, seem unimportant in natural soil bacterial communities. Negative relationships could be attributed to fitness differences leading to the overrepresentation of few productive clades, a mechanism recently invoked to assemble soil bacteria communities. We tested in two ecosystems contrasting in terms of environmental heterogeneity whether two metrics of phylogenetic community structure, a simpler measure of phylogenetic diversity (NRI) and a more complex metric incorporating taxonomic identity (PCPS), correctly predict microbially mediated EF. We show that the relationship between phylogenetic diversity and EF depends on the taxonomic identity of the main coexisting lineages. Phylogenetic diversity was negatively related to EF in soils where a marked fertility gradient exists and a single and productive clade (Proteobacteria) outcompete other clades in the most fertile plots. However, phylogenetic diversity was unrelated to EF in soils where the fertility gradient is less marked and Proteobacteria coexist with other abundant lineages. Including the taxonomic identity of bacterial lineages in metrics of phylogenetic community structure allows the prediction of EF in both ecosystems.
authors: Centro de Investigaciones sobre Desertificación (CSIC-UVEG-GV), Carretera Moncada - Náquera, Km 4.5, E-46113 Moncada, Valencia, Spain.
authors: Eduardo
authors: E
authors: Pérez-Valera
authors: Centro de Investigaciones sobre Desertificación (CSIC-UVEG-GV), Carretera Moncada - Náquera, Km 4.5, E-46113 Moncada, Valencia, Spain.
authors: Marta
authors: M
authors: Goberna
authors: Centro de Investigaciones sobre Desertificación (CSIC-UVEG-GV), Carretera Moncada - Náquera, Km 4.5, E-46113 Moncada, Valencia, Spain miguel.verdu@uv.es.
authors: Miguel
authors: M
authors: Verdú
mesh_terms: D039903:Actinobacteria / Q000145:classification* / Q000235:genetics; D001483:Base Sequence; D044822:Biodiversity; D004269:DNA, Bacterial / Q000235:genetics; D017753:Ecosystem; D019083:Mediterranean Region; D059013:Microbial Consortia / Q000235:genetics*; D010802:Phylogeny; D020560:Proteobacteria / Q000145:classification* / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012987:Soil
keywords: Proteobacteria; competitive exclusion; fitness differences; phylogenetic clustering; phylogenetic diversity; taxonomic identity