DOI: 10.5061/dryad.3q9k0
title: Data from: Consumer trait variation influences tri-trophic interactions in salt marsh communities

description: The importance of intraspecific variation has emerged as a key question in
 community ecology, helping to bridge the gap between ecology and
 evolution. Although much of this work has focused on plant species, recent
 syntheses have highlighted the prevalence and potential importance of
 morphological, behavioral, and life history variation within animals for
 ecological and evolutionary processes. Many small-bodied consumers live on
 the plant that they consume, often resulting in host plant-associated
 trait variation within and across consumer species. Given the central
 position of consumer species within tritrophic food webs, such consumer
 trait variation may play a particularly important role in mediating
 trophic dynamics, including trophic cascades. In this study, we used a
 series of field surveys and laboratory experiments to document
 intraspecific trait variation in a key consumer species, the marsh
 periwinkle Littoraria irrorata, based on its host plant species (Spartina
 alterniflora or Juncus roemerianus) in a mixed species assemblage. We then
 conducted a 12-week mesocosm experiment to examine the effects of
 Littoraria trait variation on plant community structure and dynamics in a
 tritrophic salt marsh food web. Littoraria from different host plant
 species varied across a suite of morphological and behavioral traits.
 These consumer trait differences interacted with plant community
 composition and predator presence to affect overall plant stem height, as
 well as differentially alter the density and biomass of the two key plant
 species in this system. Whether due to genetic differences or phenotypic
 plasticity, trait differences between consumer types had significant
 ecological consequences for the tritrophic marsh food web over seasonal
 time scales. By altering the cascading effects of the top predator on
 plant community structure and dynamics, consumer differences may generate
 a feedback over longer time scales, which in turn influences the degree of
 trait divergence in subsequent consumer populations.
description: Snail morphological
 trait variationVariation in shell
 morphology of Littoraria irrorata snails from Spartina alterniflora or
 Juncus roemerianus host plantshughes_snail_morphology.csvSnail stable isotope variationVariation in C and N stable isotopes for Littoraria irrorata snails from Spartina alterniflora or Juncus roemerianus host plantshughes_snail_stableisotope.csvSnail feeding assayResults of a lab feeding trial with Littoraria irrorata snails from Spartina alterniflora or Juncus roemerianus host plants feeding on plant-based agarhughes_feeding_assay.csvSusceptibility of live snails to predationResults of laboratory trial testing the susceptibility of Littoraria irrorata snails from Spartina alterniflora or Juncus roemerianus host plants to predation by the crown conch Melongena coronahughes_live_snail_susceptibility_trial.csvSusceptibility of dead snails to predationResults of lab experiment testing susceptibility of dead Littoraria irrorata snails from Spartina alterniflora or Juncus roemerianus host plants to predation by the crown conch Melongena coronahughes_dead_snail_susceptibility_trial.csvMesocosm experimentResults of a mesocosm experiment testing the effects of snail type (Littoraria irrorata from Spartina alterniflora or Juncus roemerianus host plants), plant community (Spartina alterniflora only, Juncus roemerianus only, or Spartina and Juncus mix), and predator presence (Melongena corona) on plant density, height, and biomasshughes_mesocosm_exp.csvSnail climbing behavior at high tide in mesocosm experimentNumber of Littoraria irrorata snails climbing on plant stems at high tide during a mesocosm experimenthughes_mesocosm_snail_behavior_high_tide.csvSnail climbing behavior at low tide in a mesocosm experimentNumber of Littoraria irrorata snails climbing plant stems in a mesocosm experimenthughes_mesocosm_snail_behavior_low_tide.csv