DOI: 10.5061/dryad.wwpzgmssg
title: Data from: Release from aboveground enemies increases seedling survival in grasslands

description: Plant enemies can influence plant community assembly and structure.
 However, it is unclear how insect herbivores and fungal pathogens affect
 seedling recruitment. Complex interactions with competition and resource
 availability make it difficult to isolate the effect of enemies. This
 uncertainty can impede understanding of community assembly drivers,
 species coexistence, and trophic interactions; and limits hypothesis
 testing such as the enemy release hypothesis, a key hypothesis in invasion
 biology. Using a novel species-specific approach, we examine how enemies
 affect seedling survival and recruitment of 16 grassland species. We
 planted seedlings of 16 native species from two functional groups (C4
 grasses and non-legume forbs) into two grassland sites (early and mid
 succession). We hand-painted 1,548 individual seedlings with pesticides
 (insecticide and fungicide) over the course of one growing season to
 enforce aboveground species-specific release from enemies, and tested
 whether it enhanced survival relative to untreated controls. Applying
 treatments to individuals allowed us to test for the effect of enemies on
 plant performance while controlling for contexts such as competition from
 the resident community and resource levels. Release from insects increased
 seedling survival by 56% on average, with no additional benefit of release
 from fungal pathogens. This effect was observed for both forbs and C4
 grasses across both sites, and was strongest in resource-acquisitive
 species. There was no effect of the mean phylogenetic distance between our
 target species and the resident plant community, or of light availability
 or soil moisture. Synthesis. The significant positive effect of release
 from insect herbivores on survival early in colonisation – a trend that
 held across functional groups and types of resident communities – suggests
 insects play an important regulatory role in community assembly,
 especially for resource-acquisitive species. As variation between species
 could be explained by traits but not by phylogeny, we emphasise the
 importance of trait-based approaches to plant community ecology. Our
 results also support the key mechanism (increased performance following
 release from enemies) underlying the enemy release hypothesis. Enemy
 release may therefore aid initial recruitment of plants during the
 invasion process.
description: This dataset is based on an experiment carried out at Cedar Creek
 Ecosystem Science Reserve, Minnesota, USA. In this experiment, seedlings
 of 16 different species were planted into two naturally occurring
 grasslands; one early-successional sites and one mid-successional site.
 The seedlings were treated with either insecticide, insecticide, and
 fungicide, or a control treatment, and seedling survival was monitored for
 two months. Relative seedling survival was compared among the three
 treatments, and correlated with environmental conditions, species-level
 traits, phylogenetic relatedness, and damage by insects and fungal
 pathogens.
description: # Data from: Release from aboveground enemies increases seedling survival
 in grasslands Journal of Ecology *Joshua I. Brian, Harry E. R. Shepherd,
 María Ángeles Pérez-Navarro, Jane A. Catford* ## Background: This dataset
 is based on an experiment carried out at Cedar Creek Ecosystem Science
 Reserve, Minnesota, USA. In this experiment, seedlings of 16 different
 species were planted into two naturally occurring grasslands; one
 early-successional site and one mid-successional site. The seedlings were
 treated with either insecticide, insecticide and fungicide, or a control
 treatment, and seedling survival was monitored for two months. Relative
 seedling survival was compared among the three treatments, and correlated
 with environmental conditions, species-level traits, phylogenetic
 relatedness and damage by insects and fungal pathogens.   The current
 submission allows for the reproduction of all analyses and figures as
 described in the paper. ## Data description and file structure: The data
 consists of sixteen files: one code file and fifteen data files. ### *Code
 file:* `Supporting Information Code S1.R` * Contains code to replicate all
 analyses and figures. It also contains detailed usage notes for the below
 data files. #### *Data files* (note: each bullet point under each data
 file is a column name in that data file, followed by a description of that
 column): `abundances.csv` * plot: the experimental plot (ranges from 1 to
 288) * abundance: the percent cover of each species in the plot * species:
 a list of species found in each plot * specieslowbar: as per previous
 column, but with genus and species names separated by '_' *
 genus: genus of each species * family: family of each species *
 species.relative: nearest related species to the listed species (mostly
 blank, filled in if the species does not appear in backbone tree of Jin
 & Qian 2019) * genus.relative: genus used to interpolate species into
 tree if no suitable sister species available   `damage_E.csv` * species:
 5-letter abbreviation for each of the 16 species * plot: the experimental
 plot; ranges from 1 to 144 as this data is from early site only *
 treatment: the experimental treatment; either C (control), I
 (insecticide), IF (insecticide + fungicide) * plantnumber: the identifying
 number for each plant in the plot (ranges from 1-6). Only plants that
 survived until end of season appear in the dataset * leaf1i – leaf5f (10
 columns total): percent of leaf damaged by either insects (i suffix) or
 fungal pathogens (f suffix). Data from 5 leaves total. Blank if plant had
 less than 5 leaves * height: height of plant at end of season (mm) *
 meaninsect: mean insect damage (percent of leaf removed) across all 5
 leaves * mean fungal: mean fungal damage (percent of leaf infected) across
 all 5 leaves `damage_M.csv` * all columns as per `damage_E.csv`, but for
 plants from the mid site `damage_overall.csv` * species: 5-letter
 abbreviation for each of the 16 species * plot: the experimental plot;
 ranges from 1 to 288 * richness: the number of other naturally occurring
 species in each plot * treatment: the experimental treatment; either C
 (control), I (insecticide), IF (insecticide + fungicide) * plantnumber:
 the identifying number for each plant in the plot (ranges from 1-6). Only
 plants that survived until end of season appear in the dataset * damage:
 the percent of each plant damaged (average of 5 leaves) * type: whether
 the damage was caused by insects (ins) or fungal pathogens (fun) * stage:
 whether the plot is at the early (E) or mid (M) successional stage *
 combo: a composite column combining the information in the treatment, type
 and stage columns   `effect_size_species.csv` * treatment: the
 experimental treatment; I (insecticide), IF (insecticide + fungicide) *
 species: the 16 species in the experiment * growth: whether the species is
 a forb or a grass * ef: effect size of the treatment relative to the
 control (from model set 3) * cilower: 95% lower confidence interval of the
 effect size * ciupper: 95% upper confidence interval of the effect size *
 meaninsectdamageC: mean insect damage on control plants of that species *
 meanfungaldamageC: mean fungal pathoegn damage on control plants of that
 species * meaninsectfungaldamageC: combined mean insect and fungal
 pathogen damage on control plants of that species  
 `effect_sizes_individuallevel.csv` * treatment: the experimental
 treatment; I (insecticide), IF (insecticide + fungicide) * time: the
 number of weeks since beginning of the experiment * ef: effect size of the
 treatment relative to the control (from model set 2) * cilower: 95% lower
 confidence interval of the effect size * ciupper: 95% upper confidence
 interval of the effect size   `effect_sizes_other.csv` * time: the number
 of weeks since beginning of the experiment * efstage: the effect size of
 being in mid-succession relative to early succession (from model set 1a) *
 cilowerstage: 95% lower confidence interval of the stage effect size *
 ciupperstage: 95% upper confidence interval of the stage effect size *
 efrichness: the effect size of a one-species increase in plot species
 richness * cilowerrichness: 95% lower confidence interval of the richness
 effect size * ciupperrichness: 95% upper confidence interval of the
 richness effect size   `effect_sizes_plotlevel.csv` * treatment: the
 experimental treatment; I (insecticide), IF (insecticide + fungicide) *
 time: the number of weeks since beginning of the experiment * ef: effect
 size of the treatment relative to the control (from model set 1) *
 cilower: 95% lower confidence interval of the effect size * ciupper: 95%
 upper confidence interval of the effect size   `new_dead.csv` * species:
 5-letter abbreviation for each of the 16 species * functional: whether the
 species is grass or forb * treatment: the experimental treatment; either C
 (control), I (insecticide), IF (insecticide + fungicide) * stage: whether
 the plot is at the early (E) or mid (M) successional stage * plotnumber:
 the experimental plot (ranges from 1 to 288) * awMPD: abundance-weighted
 mean phylogenetic distance between the focal planted species and the rest
 of the plant community. Standardised to have mean 0 and standard deviation
 1 * moisture: the moisture level of each plot (% moisture). Standardised
 to have mean 0 and standard deviation 1 * lightavailable: the percentage
 of available light through the canopy. Standardised to have mean 0 and
 standard deviation 1 * richness: the number of species naturally occurring
 in the plot. Standardised to have mean 0 and standard deviation 1 * date:
 the number of weeks since beginning of the experiment * mean: the
 proportion of plants surviving in the plot * newdead: the number of plants
 that died between the preceding date and the current date
 `pca_results_modified.csv` * species: the 16 species in the experiment *
 funcgroup: whether the species is grass or forb * PC1aboveground: value of
 PC1 from a principal components analysis from aboveground traits of all 16
 species * PC2aboveground: value of PC2 from a principal components
 analysis from aboveground traits of all 16 species * SLA: mean specific
 leaf area for each species (mm2 mg-1) * N: mean % nitrogen content in
 leaves for each species * effectsizeI: effect size of insecticide
 treatment relative to control (from model set 3) * logeffectsizeI: log of
 the previous column * effectsizeIF: effect size of insecticide + fungicide
 treatment relative to control (from model set 3) * logeffectsizeIF: log of
 the previous column   `phylo_effect.csv` * species: the 16 species in the
 experiment * specieslowbar: as per previous column, but with genus and
 species names separated by '_' * genus: genus of each species *
 family: family of each species * species.relative: nearest related species
 to the listed species (mostly blank, filled in if the species does not
 appear in backbone tree of Jin & Qian 2019) * genus.relative: genus
 used to interpolate species into tree if no suitable sister species
 available * effectsizeI: effect size of insecticide treatment relative to
 control (from model set 3) * effectsizeIF: effect size of insecticide +
 fungicide treatment relative to control (from model set 3)  
 `plot_richness.csv` * plotnumber: the experimental plot; ranges from 1 to
 288 * richness: the number of species naturally occurring in the plot  
 `siteNMDS.csv` * Plot: plot code for various old field plots at Cedar
 Creek * group: whether the plot is Early (15-25 years post-abandonment) or
 Mid (36-46 years post-abandonment) * exp: the experiment the plots come
 from; either 'Old_fields' (general old fields at Cedar Creek) or
 'MechER' (the experiment described in the paper) * columns E to
 DG: species at Cedar Creek and their percent cover in each plot  
 `species_traits_all.csv` * species: the 16 species in the experiment *
 funcgroup: whether the species is grass or forb * LDMC: mean leaf dried
 matter content for each species (mg g-1) * leaf_area: mean leaf area for
 each species (mm2) * SLA: mean specific leaf area for each species (mm2
 mg-1) * N: mean % leaf N for each species * P: mean % leaf P for each
 species * leaf_dry_mass: mean dry mass for each species (g) *
 leaf_fresh_mass: mean fresh mass for each species (g) * height: mean
 height of plant (cm) * seed_mass: mean mass of single seed (g)
 `survival_data.csv` * species: 5-letter abbreviation for each of the 16
 species * functional: whether the species is grass or forb * treatment:
 the experimental treatment; either C (control), I (insecticide), IF
 (insecticide + fungicide) * stage: whether the plot is at the early (E) or
 mid (M) successional stage * replicate: the replicate number for each
 treatment for each species (a, b or c) * plantnumber: the identifying
 number for each plant in the plot (ranges from 1-6) * plotnumber: the
 experimental plot; ranges from 1 to 288 * awMPD: abundance-weighted mean
 phylogenetic distance between the focal planted species and the rest of
 the plant community * moisture: the moisture level of each plot (%
 moisture) * lightavailable: the percentage of available light through the
 canopy * heightinitial: seedling height (mm) when planted * date: the time
 period the observation was made at (1-7) * survived: whether the seedling
 was alive (1) or dead (0) ## Sharing and access information The dataset is
 free to download and use under the conditions of the CC0 license.