DOI: 10.5061/dryad.v0t4qm3
title: Data from: Snail herbivory affects seedling establishment in a temperate forest in the Ozark region

description: 1. Species-specific herbivores are hypothesized to maintain plant
 diversity by preventing the dominance of any one plant species. However, a
 large proportion of herbivores have wide host ranges, and these
 generalists could have similar effects on plant community composition if
 they exhibit differences in their host preference. Here, we coupled lab
 and field experiments to test whether a common forest-understory snail
 (Neohelix alleni), a generalist herbivore, has the potential to influence
 forest composition through differential preference of their plant hosts.
 2. We first performed a cafeteria-style experiment to test whether N.
 alleni shows feeding preferences among leaves of five tree species and one
 shrub common to temperate forests in Missouri, USA. We then conducted a
 factorial snail and deer exclusion experiment to decouple the effects of
 snail herbivory from those of white-tailed deer on seedling establishment
 of 1 month-old newly germinated seedlings of these six tree woody species
 in the field. Finally, we examined whether variation in both snail feeding
 preference and experimentally measured effects of snails on seedling
 establishment across plant species were related to their tree species
 relative abundance measured in a 12-ha forest plot. 3. In the lab, we
 found that snails preferred leaves of tree woody species that were less
 abundant in the forests relative to those species that were more common.
 In the forest, we found that experimental exclusion of snails had a
 stronger positive effect on seedling aboveground biomass and survival over
 a 1-year period than did exclusion of deer. tree Plant species found to be
 more preferred in the lab were also those that had lower seedling
 establishment in the forest due to the negative effects of snails. 4.
 Synthesis. Collectively, our results suggest that greater susceptibility
 to snail herbivory limit seedling establishment, perhaps contributing to
 differences in tree species relative abundance. Although less appreciated
 than their insect and mammal counterparts, herbivory by snails may be
 significant drivers to the assembly of forest tree communities.
description: All
 data.Data include results
 from a cafeteria-style preference experiment, observational data of
 relative abundances of tree species across a 12-ha forest plot and results
 from factorial snail and deer exclusion field experiments. Data for each
 figure in the manuscript are shown on separate spreadsheets. Abbreviated
 headlines are as follows: "species" = plant species,
 "abund" = % abundance plant species across 12-ha forest plot,
 "loss" = % biomass loss due to snail feeding, "SE
 loss" = standarderror for biomass loss, "feeding_rank" = 1
 (least preferred) to 6 (most preferred by snails),
 "snail_treatment" = snail addition, exclusion or not manipulated
 (control) in the field experiments, "biomass" = LSmeans of
 seedling biomass after 1 year in field experiment, "SE" =
 standarderror for biomass, "log_response" = log response ratio
 of species biomass to the 'snails added' treatment relative to
 the ‘snail exclusion’ treatment, "CI" = 95% confidence
 interval.snail_alldata.xlsx