Data from: Release from aboveground enemies increases seedling survival in grasslands
Data files
Apr 10, 2024 version files 1.88 MB
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abundances.csv
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damage_E.csv
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damage_M.csv
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damage_overall.csv
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effect_size_species.csv
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effect_sizes_individuallevel.csv
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effect_sizes_other.csv
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effect_sizes_plotlevel.csv
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new_dead.csv
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pca_results_modified.csv
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phylo_effect.csv
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plot_richness.csv
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README.md
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siteNMDS.csv
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species_traits_all.csv
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Supporting_Information_Code_S1.R
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survival_data.csv
Abstract
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.
README: 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.
Methods
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.