DOI: 10.5061/dryad.g7f45
title: Data from: Traits underlying community consequences of plant intra-specific diversity

description: A plant’s performance and interactions with other trophic levels are
 recorgnized to be contingent upon plant diversity and underlying
 associational dynamics, but far less is known about the plant traits
 driving such phenomena. We manipulated diversity in plant traits using
 pairs of plant and a substitutive design to elucidate the mechanisms
 underlying diversity effects operating at a fine spatial scale.
 Specifically, we measured the effects of diversity in sex (sexual
 monocultures vs. male and female genotypes together) and growth rate
 (growth rate monocultures vs. fast- and slow-growing genotypes together)
 on growth of the shrub Baccharis salicifolia and on above- and belowground
 consumers associated with this plant. We compared effects on associate
 abundance (# associates per plant) vs. density (# associates per kg plant
 biomass) to elucidate the mechanisms underlying diversity effects; effects
 on abundance but not density suggest diversity effects are mediated by
 resource abundance (i.e. plant biomass) alone, whereas effects on density
 suggest diversity effects are mediated by plant-based heterogeneity or
 quality. Sexual diversity increased root growth but reduced the density
 (but not abundance) of the dietary generalist aphid Aphis gossypii and its
 associated aphid-tending ants, suggesting sex mixtures were of lower
 quality to this herbivore (e.g. via reduced plant quality), and that this
 effect indirectly influenced ants. Sexual diversity had no effect on the
 abundance or density of parasitoids attacking A. gossypii, the dietary
 specialist aphid Uroleucon macolai, or mycorrhizae. In contrast, growth
 rate diversity did not influence plant growth or any associates except for
 the dietary specialist aphid U. macolai, which increased in both abundance
 and density at high diversity, suggesting growth rate mixtures were of
 higher quality to this herbivore. These results highlight that plant
 associational and diversity effects on consumers are contingent upon the
 source of plant trait variation, and that the nature of such dynamics may
 vary both within and among trophic levels.
description: DRYADdata_Abdala-RobetalThis file contains all data for Abdala-Roberts et al. accepted to PLoS-One in August, 2017, titled "Traits underlying community consequences of plant intra-specific diversity." The data are structured by plot (1-10) and planting positions in each plot (1-9). Each row provides data for a pair of plants and describes either plant biomass for the pair or the associates of the pair (arthropods or colonization by mycorrhizae). The design of the experiment is fully explained in the manuscript. Within each plot, pairs of plants are coded as "ff", "ss" or "fs" for both being fast growing, slow growing, or a polyculture of each (one fast and one slow). Similarly, pairs of plants are coded as "mm", "ff" or "fm" for both being males, females, or a polyculture of both (one male and one female). The variables predators, ant, Uroleucon, Aphis, and Aphisparasitoids are predatory arthropods, Linepithema humile, Uroleucon macolai, Aphis gossypii, or the parasitoids of A.g., respectively.