DOI: 10.5061/dryad.mp1bk57
title: Data from: The relative importance of plant intraspecific diversity in structuring arthropod communities: a meta-analysis

description: 1. Understanding how plant diversity influences higher trophic levels is
 important for predicting the consequences of global biodiversity loss.
 While early studies have focused on the effects of plant species richness,
 more recently a growing number of experiments have explored the effects of
 plant intraspecific diversity by manipulating the genotypic richness of
 plant communities. 2. By combining 162 estimates of effect size from 60
 experimental studies, we examined the effects of plant genotypic richness
 on arthropods, one of the most diverse and abundant taxa which play a
 crucial role in many ecosystem processes and services. We have also
 compared the effects of plant genetic and species diversity on arthropods
 when both were manipulated within the same study. 3. Species richness and
 abundance of most trophic groups of arthropods was higher in genetically
 diverse plant stands. Interestingly, the effects of plant genetic
 diversity on natural enemies of herbivores were stronger than the effects
 of plant genetic diversity on herbivores, suggesting that plant genetic
 diversity effects on predators might be driven by mechanisms independent
 of herbivores. 4. Herbivore and predator abundance increased with plant
 genetic diversity in studies using wild plants whereas predator abundance
 was unaffected and herbivore abundance was reduced by crop genetic
 diversity. Damage by generalist herbivores was reduced by plant genetic
 diversity whereas damage by specialist herbivores was not affected. 5.
 When the effects of plant genetic and species diversity on arthropods were
 compared within the same study, the magnitude of plant genetic diversity
 effects was comparable to that of plant species diversity. 6. Our results
 suggest that plant genetic diversity has significant effects on the
 diversity of arthropods across several trophic levels, thus highlighting
 the importance of maintaining high levels of both plant species and
 genetic diversity for arthropod conservation. However, the potential of
 using crop genetic mixtures in agriculture for pest control appears to be
 limited as even though herbivore abundance was reduced in genetically
 diverse plots, herbivore damage and predator abundance were not affected
 by crop genotypic richness.
description: Database for the
 meta-analysis of plant intraspecific diversity effects on
 arthropodsDatafile includes
 reference to a study from which the data have been extracted, trophic
 level of arthropods examined in the study, feeding specialization for
 herbivores (specialist/generalist), plant species, info on whether several
 plant genotypes or just a single plant genotype were represented in
 monocultures, plant type (crop/wild), arthropod response variable measured
 (species richness=richness, diversity=Shannon-Weiner index; evenness,
 abundance, damage (for herbivores, e.g. % leaf area damage), parasitism
 rate (for parasitoids), fecundity or biomass), effect size (Hedges'
 d) and variance of the effect size (var d). The full list of references
 used in the meta-analysis is available in the original paper (data sources
 for the meta-analysis)FE genetic diversity
 database.xlsxComparison of genetic vs
 species diversity effectsDataset for comparison
 of plant genetic and species diversity effects on arhtropods including
 reference from which the data were extracted, trophic level of arthropods,
 response variable, effect size (Hedges' d and variance for plant
 genetic diversity effects, and effect size and variance for plant species
 diversity effects.