DOI: 10.5061/dryad.6f774
title: Data from: Phylogenetic relatedness, phenotypic similarity, and plant-soil feedbacks

description: Plant–soil feedbacks contribute to species invasions, the maintenance of
 biodiversity and climate change impacts on terrestrial ecosystems. Despite
 their far-reaching importance, we lack a general understanding of the
 ecological and evolutionary determinants of plant–soil feedbacks. We
 conducted a large-scale plant–soil feedback experiment using 49
 co-occurring plant species from southern Ontario, Canada, representing a
 wide phylogenetic range. We tested whether the effects of soil
 conditioning vary among these species and whether different focal species
 respond similarly to the same soil conditioning. Next, we investigated
 whether plant traits and soil feedbacks depend on phylogenetic similarity
 and which plant traits affect plant–soil feedbacks between pairs of plant
 species. Finally, we used our experimental results to test whether soil
 feedbacks affect co-occurrence of species in the field. We found evidence
 of both strong positive and negative soil feedbacks between pairs of plant
 species. Our soil-conditioning treatment explained nearly 20% of the
 variation in focal species performance. Phylogenetic relatedness and
 phenotypic similarity between plant species were unrelated to the strength
 of their soil feedback. However, numerous plant traits of the conditioning
 species influenced the strength of soil feedbacks on focal species,
 including specific leaf area and total above-ground productivity. Trait
 differences between species were also predictive of plant–soil feedbacks,
 though for some pairs of species, increased trait differences were
 associated with positive plant–soil feedbacks and for others, trait
 differences were associated with negative plant–soil feedbacks. Plant
 species co-occurrence in the field was related to their experimentally
 determined soil feedbacks but only for particular plant species.
 Synthesis. Our results illustrate how evolutionary history and phenotypic
 variation shape plant–soil feedbacks and highlight the need for
 trait-based studies. Due to the unique evolutionary history of individual
 traits and the variability in their importance across all possible
 interacting species, we show that indices of overall phenotypic and
 phylogenetic relatedness are poor predictors of plant–soil feedbacks at
 large phylogenetic scales. We conclude that a detailed trait-based
 approach can be used to predict plant–soil feedbacks, and laboratory
 measures of soil feedbacks can explain patterns of co-occurrence in
 nature.
description: Fitzpatrick.et.al.2016PSFPerformance data of focal species in conditioned soil. Block = spatial block in growth chamber. Species = numerical ID for focal plant species. Soil = numerical ID for soil conditioning plant species. See readme file for species names. AGB = aboveground biomass of focal species in particular soil treatment. BGB = belowground biomass of focal species in particular soil treatment. Species.exotic = exotic/native status of focal species. Soil.exotic = exotic/native status of soil conditioning species.Trait.dataTrait data for every species in experiment. agb = aboveground biomass; bgb = belowground biomass; rl = root length; ra = root angle; water = leaf water content; sla = specific leaf area; rhd = root hair density; srl = specific root length. sd = standard deviation; se = standard error; n = number of independent measurements.TraitDataCombined.csvfieldsurveyCo-occurence data. Population = replicate population; distance = distance between focal species and competitor; feedback = the measured feedback between each pair of focal X soil-conditioning species (see methods in paper) calculated for above-, belowground, and total biomass.Phylogenetic treePhylogenetic tree including all 49 species (see methods for protocol).final.tre