Data from: Niche dynamics of alien plant species in Mediterranean Europe
Data files
Jul 31, 2025 version files 3.12 GB
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dataset_0103.csv
76.22 KB
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EVAE.70.Rda
1.48 KB
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EVAT.30.Rda
1.46 KB
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GBIF_BKG_2Msampled_4resp.curv.Rda
55.65 MB
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GBIF_grilled.P2.Rda
24.14 MB
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ly.names.def.Rda
148 B
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myexpl.var30_Global_used.tif
3 GB
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myexpl.var30_ST_DEF.tif
33.37 MB
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Niche_analyses_NEW_results_real_DEF.zip
1.46 MB
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NicheResults_NoEVANEW_Extraction.R
7.32 KB
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README.md
27.10 KB
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Sup._Mat._data_submitted_to_Dryad.csv
71.08 KB
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TDWG_level-3_regions.zip
3.70 MB
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Third_article_Niche_an._after_Grenoble.R
19.67 KB
Abstract
Aim: Humans have spread plants globally for millennia, inadvertently causing ecological disruptions. However, biological invasions also provide a unique opportunity to study the process of niche dynamics, through which species adapt their niche when confronted with novel environments. Focusing on the Mediterranean basin, we assessed 1) which traits favour niche dynamics, and 2) whether niche conservatism or niche shift promotes invasion success.
Location: Mediterranean Europe and the World.
Results: We found that niche shifts were common (71% of species) and were mostly driven by species failing to occupy all suitable environments of their invaded range (unfilling), regardless of residence time. Niche unfilling and niche expansion were more important in species with high ITV, introduced from non-mediterranean biomes (temperate or tropical). Niche expansion was also greater for species that can disperse further, and have bigger seeds and a narrow native niche. Interestingly, invasion success was more correlated with a species’ ability to conserve its niche and residence time than niche expansion.
Main conclusions: Niche shifts were better predicted by species traits than residence time. For example, high adaptive potential (inferred from high ITV) favoured niche shifts in general, and long-distance dispersal favoured niche expansion. Understanding how these traits relate to niche dynamics is important since a species' ability to conserve and fill its niche is in turn a good predictor of invasion success.
https://doi.org/10.5061/dryad.cc2fqz6gc
Description of the data and file structure
Data were collected for the paper "Niche dynamics of alien plant species in Mediterranean Europe". Here, you can find the original data and code used in the analyses — shared for the purpose of open science. For this work, we selected the 80 most widespread alien vascular plants in Mediterranean Europe and compiled data on their distribution in their native and invaded ranges (GBIF data https://doi.org/10.15468/dl.mdkwsz). We then used the "ecospat" (https://doi.org/10.1111/ecog.02671) package to estimate niche shifts and niche dynamics for our set of 80 species. We finally built models to compare niche shifts to species' ecological characteristics and other biogeographic characteristics of the species (available in the Supplementary Materials of the paper).
Files and variables
File: EVAE.70.Rda
Description: This file has only two rows and all the species names as columns. This was originally used as a presence/absence dataset with rows as cells and species names and their presence/absence (i.e., 0,1 in the table). In this work, it is only used to define the species names of the species we analyse. The file could be opened in R, and it is needed to reproduce the code and is called in the R code "Third_article_Niche_an._after_Grenoble.R".
File: EVAT.30.Rda
Description: This file has only two rows and all the species names as columns. This was originally used as a presence/absence dataset with rows as cells and species names and their presence/absence (i.e., 0,1 in the table). In this work, it is only used to define the species names of the species we analyse. This and the previous dataset (EVAE.70.Rda) need to be combined. The file is needed to reproduce the code, it could be opened in R and it's called into the R code "Third_article_Niche_an._after_Grenoble.R".
File: ly.names.def.Rda
Description: Names of the environmental variables stored in both "myexpl.var30_ST_DEF.tif" and "myexpl.var30_Global_used.tif" files. The names stored are: "CHELSA_bio10_07", "CHELSA_bio10_10", "CHELSA_bio10_16", "CHELSA_bio10_17" obtained from CHELSA at https://chelsa-climate.org (Version 1.2 measured in Celsius degrees (bio07 and bio10, and mm/quarter both bio16 and bio17)), "BLDFIE_M" Soil bulk density data were obtained from ISRIC at https://data.isric.org/geonetwork/srv/eng/catalog.search#/metadata/2ebc3811-2783-4fb6-bb68-e8af47d32fd3 (Version 1.0 measured as kg/m³) and "Population.density.2000" and "TWI" which however were not used for this analysis. These are the variable names for the environmental variables. The file is needed to reproduce the code and it's called into the R code "Third_article_Niche_an._after_Grenoble.R".
File: dataset_0103.csv
Description: The dataset has POWO REGIONS in rows and species in columns. The dataset was manually compiled from https://powo.science.kew.org/ to define each species' native range with a TDWG level-3 regions accuracy.
Variables
- ID: a unique ID for the regions
- POWO REGIONS: Region name
- Acacia.dealbata: 0/1 for species origin in the region or not
- Acacia.saligna: 0/1 for species origin in the region or not
- Acer.negundo: 0/1 for species origin in the region or not
- Agave.americana: 0/1 for species origin in the region or not
- Ageratina.adenophora: 0/1 for species origin in the region or not
- Ailanthus.altissima: 0/1 for species origin in the region or not
- Amaranthus.albus: 0/1 for species origin in the region or not
- Amaranthus.blitoides: 0/1 for species origin in the region or not
- Amaranthus.cruentus: 0/1 for species origin in the region or not
- Amaranthus.deflexus: 0/1 for species origin in the region or not
- Amaranthus.emarginatus: 0/1 for species origin in the region or not
- Amaranthus.hybridus: 0/1 for species origin in the region or not
- Amaranthus.powellii: 0/1 for species origin in the region or not
- Amaranthus.retroflexus: 0/1 for species origin in the region or not
- Amaranthus.viridis: 0/1 for species origin in the region or not
- Ambrosia.artemisiifolia: 0/1 for species origin in the region or not
- Ambrosia.psilostachya: 0/1 for species origin in the region or not
- Amorpha.fruticosa: 0/1 for species origin in the region or not
- Arctotheca.calendula: 0/1 for species origin in the region or not
- Artemisia.verlotiorum: 0/1 for species origin in the region or not
- Baccharis.halimifolia: 0/1 for species origin in the region or not
- Bidens.aureus: 0/1 for species origin in the region or not
- Bidens.frondosus: 0/1 for species origin in the region or not
- Buddleja.davidii: 0/1 for species origin in the region or not
- Carpobrotus.acinaciformis: 0/1 for species origin in the region or not
- Carpobrotus.edulis: 0/1 for species origin in the region or not
- Ceratochloa.cathartica: 0/1 for species origin in the region or not
- Cortaderia.selloana: 0/1 for species origin in the region or not
- Cotula.coronopifolia: 0/1 for species origin in the region or not
- Crassula.lycopodioides: 0/1 for species origin in the region or not
- Cuscuta.campestris: 0/1 for species origin in the region or not
- Cyperus.eragrostis: 0/1 for species origin in the region or not
- Datura.stramonium: 0/1 for species origin in the region or not
- Digitaria.ciliaris: 0/1 for species origin in the region or not
- Echinochloa.oryzoides: 0/1 for species origin in the region or not
- Eleusine.indica: 0/1 for species origin in the region or not
- Erigeron.annuus: 0/1 for species origin in the region or not
- Erigeron.bonariensis: 0/1 for species origin in the region or not
- Erigeron.canadensis: 0/1 for species origin in the region or not
- Erigeron.floribundus: 0/1 for species origin in the region or not
- Erigeron.karvinskianus: 0/1 for species origin in the region or not
- Erigeron.sumatrensis: 0/1 for species origin in the region or not
- Euphorbia.maculata: 0/1 for species origin in the region or not
- Euphorbia.prostrata: 0/1 for species origin in the region or not
- Galinsoga.parviflora: 0/1 for species origin in the region or not
- Galinsoga.quadriradiata: 0/1 for species origin in the region or not
- Helianthus.annuus: 0/1 for species origin in the region or not
- Helianthus.tuberosus: 0/1 for species origin in the region or not
- Impatiens.balfourii: 0/1 for species origin in the region or not
- Impatiens.glandulifera: 0/1 for species origin in the region or not
- Impatiens.parviflora: 0/1 for species origin in the region or not
- Juncus.tenuis: 0/1 for species origin in the region or not
- Lepidium.didymum: 0/1 for species origin in the region or not
- Lonicera.japonica: 0/1 for species origin in the region or not
- Lycopersicon.esculentum: 0/1 for species origin in the region or not
- Matricaria.discoidea: 0/1 for species origin in the region or not
- Mirabilis.jalapa: 0/1 for species origin in the region or not
- Morus.alba: 0/1 for species origin in the region or not
- Nicotiana.glauca: 0/1 for species origin in the region or not
- Oenothera.biennis: 0/1 for species origin in the region or not
- Opuntia.ficus.indica: 0/1 for species origin in the region or not
- Oryza.sativa: 0/1 for species origin in the region or not
- Oxalis.dillenii: 0/1 for species origin in the region or not
- Oxalis.latifolia: 0/1 for species origin in the region or not
- Oxalis.pes.caprae: 0/1 for species origin in the region or not
- Oxalis.stricta: 0/1 for species origin in the region or not
- Panicum.capillare: 0/1 for species origin in the region or not
- Panicum.dichotomiflorum: 0/1 for species origin in the region or not
- Panicum.miliaceum: 0/1 for species origin in the region or not
- Parthenocissus.quinquefolia: 0/1 for species origin in the region or not
- Paspalum.dilatatum: 0/1 for species origin in the region or not
- Paspalum.distichum: 0/1 for species origin in the region or not
- Paspalum.vaginatum: 0/1 for species origin in the region or not
- Phytolacca.americana: 0/1 for species origin in the region or not
- Pinus.strobus: 0/1 for species origin in the region or not
- Pseudotsuga.menziesii: 0/1 for species origin in the region or not
- Quercus.rubra: 0/1 for species origin in the region or not
- Reynoutria.japonica: 0/1 for species origin in the region or not
- Ricinus.communis: 0/1 for species origin in the region or not
- Robinia.pseudoacacia: 0/1 for species origin in the region or not
- Setaria.faberi: 0/1 for species origin in the region or not
- Solanum.chenopodioides: 0/1 for species origin in the region or not
- Solanum.tuberosum: 0/1 for species origin in the region or not
- Solidago.canadensis: 0/1 for species origin in the region or not
- Solidago.gigantea: 0/1 for species origin in the region or not
- Sporobolus.indicus: 0/1 for species origin in the region or not
- Sporobolus.virginicus: 0/1 for species origin in the region or not
- Symphyotrichum.lanceolatum: 0/1 for species origin in the region or not
- Symphyotrichum.squamatum: 0/1 for species origin in the region or not
- Tradescantia.fluminensis: 0/1 for species origin in the region or not
- Xanthium.orientale: 0/1 for species origin in the region or not
- Xanthium.spinosum: 0/1 for species origin in the region or not
- Zea.mays: 0/1 for species origin in the region or not
File: GBIF_grilled.P2.Rda
Description: These are the used presences for all the species (in columns again) derived from the GBIF dataset accessed in 2022. The original downloaded data were resampled to only have one presence per species in a 1x1 km raster. We then extracted the environmental variables for these species presences to prepare a consistent table used in the analyses. So the file has the raster cells in rows, coordinates, species (presence absences) and environmental variables are in columns. These data were then elaborated in the loop present in the code, to be divided into the native and invaded range and then analysed using "ecospat" pipeline. The file is needed to reproduce the code, and it's called into the R code "Third_article_Niche_an._after_Grenoble.R".
File: GBIF_BKG_2Msampled_4resp.curv.Rda
Description: 2 million points of global background data used to identify background environmental conditions in the niche shift analyses. So the file has the raster cells in rows, coordinates, species (as only one column filled with zeros as absences) and environmental variables are in columns. During the development pipeline, these data were used to resample in a buffer the native and invaded range environmental conditions. These environmental conditions were then used to compute the shared environmental conditions in which to estimate niche shift metrics. The file is needed to reproduce the code, and it's called into the R code "Third_article_Niche_an._after_Grenoble.R". The variables names are shared with the previous datasets "GBIF_grilled.P2.Rda".
Variables
- Longitude: Longitude coordinate of the background point (centroid of raster cell) - Decimal degrees (WGS84)
- Latitude: Latitude coordinate of the background point (centroid of raster cell) - Decimal degrees (WGS84)
- CHELSA_bio10_07: Temperature annual range [°C*10]
- CHELSA_bio10_10: Mean temperature of warmest quarter [°C*10]
- CHELSA_bio10_16: Precipitation of wettest quarter [mm/quarter]
- CHELSA_bio10_17: Precipitation of driest quarter [mm/quarter]
- BLDFIE_M: Soil bulk density, measured at standard depth [kg / cubic-meter]
- Population.density.2000: Human population density in the year 2000 (log of absolute number). NOT USED IN THE ANALYSES
- TWI: Topographic Wetness Index — a compound index representing potential soil moisture. NOT USED IN THE ANALYSES
- cells: Internal raster cell identifier used for indexing spatial data. Integer numeric number
- myexpl.var30_Global_used.1: Duplicate of the first raster, i.e., Temperature annual range [°C*10]
File: NicheResults_NoEVANEW_Extraction.R
Description: The code used to extract the stored results saved by the code "Third_article_Niche_an._after_Grenoble.R". This will be a fundamental code to extract the result and produce a table directly in R for subsequent analyses.
File: Third_article_Niche_an._after_Grenoble.R
Description: The code used to estimate niche shifts in Mediterranean Europe. This represents the main parts of the computed analyses and uses the previously presented datasets to: identify the native range for each species, while the invaded range is always Mediterranean Europe. Sample background points (i.e., the general environmental conditions) and each species' presence in both Mediterranean Europe and each species native range. In the rest of the code, we computed different metrics of niche shifts, according to different theoretical questions, and saved all the results for further analyses. These results are then extracted using the code "NicheResults_NoEVANEW_Extraction.R"
File: myexpl.var30_ST_DEF.tif
Description: These are the raster data with the environmental conditions of the study area, i.e., our Mediterranean Europe. These rasters were used during the pipeline to select GBIF presences in the study area and subsample background points used for the main analyses. The variables included in these raster files have the name from (and are the same of) "ly.names.def" and hence "CHELSA_bio10_07", "CHELSA_bio10_10", "CHELSA_bio10_16", "CHELSA_bio10_17", "BLDFIE_M", "Population.density.2000", "TWI".
File: myexpl.var30_Global_used.tif
Description: These are the raster data with the environemntal conditions of the all world. These data were used during the pipeline to be clipped for each species based on their native range and to select backround points. The variables included in this raster files have the name from (and are the same of) "ly.names.def" and hence "CHELSA_bio10_07", "CHELSA_bio10_10", "CHELSA_bio10_16", "CHELSA_bio10_17", "BLDFIE_M", "Population.density.2000", "TWI".
Folder: Niche_analyses_NEW_results_real_DEF.zip
Description: These are the main results of the analyses performed in the R code "Third_article_Niche_an._after_Grenoble.R". By running the script, and after the creation of a destination folder, you will get these results for each of the 80 analysed species. In fact, these are the main raw original results of the work, which are then condensed in the supporting information of the paper, after running the script "NicheResults_NoEVANEW_Extraction.R". Some of these results are images reporting the niche similarity; in the images, there is the quantitative comparison between the native and the invaded niche. Niche similarity test results, instead, are presented as a simulated vs actual observed value.
Folder: TDWG_level-3_regions.zip
Description: This folder contains a shapefile of the TDWG level 3 regions (which are the samed used to identify the native range of the species). This dataset, combined with the dataset_0103.csv (for each species' native range) and with the raster file of the global environmental variables, were used to crop the native range conditions, select the native range presences and absences and used in the main code "Third_article_Niche_an._after_Grenoble.R" and to perform the main analyses.
File: Sup._Mat._data_submitted_to_Dryad.csv
Description: These data are presented for the purposes of reproducible science. In Italic, the corresponding column name in the data. The table has all the values needed for the modelling presented in the main text and derived from the previous niche shift analyses. This table (see every column description as a bullet point list later) with species names in rows shows in the columns the corresponding summaries of GBIF nr. of presences in the native (Nr. Nat. Pres..) and invaded range (Nr. Inv. Pres.), PCA explained variability (PCA-2 axes exp. Var.) for the niche shift framework, niche shift metrics (D sim.test = observed overlap of the niches, P-val. = results of the similarity test, Exp. = observed expansion, Unf. = observed unfilling, Niche shift Bin.* = the binarised version of niche shifts based on the similarity test, threshold 0.05), longer residence time in one of the study area country (ResidenceTime (Years), and the standardised version for modelling purposes, Res. Time Std. Global (Years)), date of the first record as an alien species globally (FirstIntroduction Global (Date)), phylogeny (Family, Family Agg. = Amaranthaceae, Compositae, Poacea or other and Grow Form = herb or tree), species dispersal ability (Disp. Synrome = the modality through which seeds are dispersed, Disp. Dist. Std. (for modelling purposed), Disp. Dist. (meters)), biogeographic origin (Biome of Orig. = among Mediterranean, Temperate and Tropical), functional traits (Perennial = for perennial or not species, Mean SLA = mean value of Surface Leaf Area (SLA) from all the observations, Mean SLA Filled = SLA filling missing values, SLA Std. = Standardised value of Surface Leaf Area used for modelling purposes, Mean SM = mean value of Seed mass (SM) from all the observations for every species, Mean SM Filled = SM filling missing values, SM Std. = Standardised value of SM used for modelling purposes, Mean RH = mean value of release high (RH, which corresponds to plant height in meters) from all the observations, Mean RH Filled = RH filling missing values, RH Std. = Standardised value of release height used for modelling purposes) and their variability (SLA sd. = Surface leaf Area (SLA) Standard deviation, SLA sd. Filles = SLA standard deviation, with filled missing values, SLA No. Ob. = Nr of observations used for the estimate of SLA metrics, SLA CV Std. = SLA coefficient of variation values standardised for modelling purposes, SM sd. = Seed mass (SM in mg) Standard deviation, SM sd. Filles = SM standard deviation, with filled missing values, SM Nr. Ob. = Nr. of observations used for the estimate of SM metrics, SM CV Std. = SM coefficient of variation values standardised for modelling purposes, RH sd. = release height (RH in meters) Standard deviation, RH sd. Filles = RH standard deviation, with filled missing values, RH Nr. Ob. = Nr of observations used for the estimate of RH metrics, RH CV Std. = RH coefficient of variation values standardised for modelling purposes), native environmental niche breadth (Native Env. Niche Breadth), invasion success metrics (Inv. Niche Breadth Inv. = regional spread of the invasive species in the environmental space, Local Abundance = mean local abundance of the species in the sampled plots, Inv. Regional Spread = regional spread in the geographic space, the Number of countries in which the species is naturalised according to GLONAFF (Nr of countries in which the species is naturalised (GLONAFF)) and niche shift metrics in the non-analogue space (NA) (D NA = observed overlap of the niches, Unf. NA = observed unfilling, Exp. NA = observed expansion, sim.test P-val. NA = results of the similarity test.
Detailed legend:
File: Sup._Mat._data_submitted_to_Dryad.csv
Description:
Variables
- sp.ID: unique species number (integer and sequential)
- Species: Scientific name of the species (string)
- Nr. Nat. Pres.: Number of GBIF presence records in the native range (as integer)
- Nr. Inv. Pres.: Number of GBIF presence records in the invaded range (as integer)
- PCA-2 axes exp. Var.: Percentage of variance explained by the first two PCA axes (per cent %)
- D: Observed niche overlap between native and invaded ranges (Schoener’s D as a percentage of overlap %)
- sim. test P-val.: P‑value from niche similarity test Probability (0–1)
- Exp.: Observed environmental niche expansion (% as a percentage)
- Unf. : Observed environmental niche unfilling (% as a percentage)
- ResidenceTime (Years): Longer residence time of the species in one study‑area country i.e., in Mediterranean Europe (years)
- Res. Time Std.: Standardised (z‑score) residence time for modelling at global scale (std. units)
- FirstIntroduction Global (Date): Date of first record as alien species globally (calendar year)
- ResidenceTime Global (Years): The Longer residence time, the species has became alien somewhere in the globe (years)
- Res. Time Std. Global (Years): Standardised (z‑score) residence time the species became alien somewhere in the globe (std. units)
- Family: Taxonomic family of the species (categorical text string)
- Family Agg.: Aggregated family category: Amaranthaceae, Compositae, Poaceae, or other (categorical text string)
- Grow Form: Growth form: herb or tree (categorical text string)
- Disp. Synrome : Dispersal syndrome (seed dispersal modality as a categorical text string)
- Disp. Dist. Std.: Standardised seed dispersal distance for modelling purposes (std. units)
- Disp. Dist. (meters): Seed dispersal distance in meters (meters)
- Biome of Orig. : Biogeographic origin: Mediterranean, Temperate, Tropical (categorical string)
- Perennial: Whether the species is perennial or not Binary (0 = no, 1 = yes)
- Mean SLA: Mean leaf area per species (specific leaf area mm2 mg−1)
- Mean SLA Filled: Mean SLA with missing values filled using imputation (mm2 mg−1)
- SLA Std.: Standardised SLA for modelling (z-score) (std. units)
- SLA sd.: Standard deviation of SLA observations (mm2 mg−1)
- SLA sd. Filles: SLA SD with missing values imputed (mm2 mg−1)
- SLA Nr. Ob.: Number of SLA observations used (integer)
- SLA CV Std.: Standardised coefficient of variation of SLA for modelling (std. units)
- Mean SM: Mean seed mass per species (mg)
- Mean SM filled: Mean SM with missing values imputed (mg)
- Mean SM Std.: Standardised seed mass for modelling (std. units)
- SM sd.: Standard deviation of SM observations (mg)
- SM Nr. Ob.: Number of seed mass observations used (units integer)
- SM CV Std.: Standardised coefficient of variation of SM (std. units)
- Mean RH: Mean release height (plant height) per species (meters)
- Mean RH Std.: Standardised release height for modelling (std. units)
- RH sd.: Standard deviation of RH observations (meters)
- RH Nr. Ob.: Number of RH observations used (integer)
- RH CV Std.: Standardised coefficient of variation of RH (std. units)
- Native Env. Niche Breadth: Environmental niche breadth in the native range (std. unit)
- Niche shift Bin.: Binary value showing if the species has shifted the niche or not. Binary (0 = no, 1 = yes)
- Inv. Niche Breadth: Regional spread of the invasive species in the environmental space (std. unit)
- Inv. Local Abundance: Mean local abundance (e.g., plot-level) in invaded range (std. unit)
- Inv. Regional Spread: Geographic spread of invasive species in invaded range (std. unit)
- Nr. of countries in which the species is naturalised (GLONAFF): Number of countries in Mediterranean Europe where the species is reported as naturalised per GLONAFF (Integer)
- D NA: NA stands for non-analogous spaces. Niche overlap in non-analogue environmental space as a percentage of overlap %
- Unf. NA: Unfilling in non-analogue space (% as a percentage)
- Exp. NA: Expansion in non-analogue space (% as a percentage)
- sim.test P-val. NA: P‑value from similarity test in non-analogue space Probability (0–1)
Code/software
All the analyses can be reproduced using the R software and by launching the shared codes.
Access information
Other publicly accessible locations of the data:
- The paper page, once published. It will contain original data on species traits.
Data was derived from the following sources:
Plant occurrence records were obtained from GBIF. The native ranges for each species were identified using Plants of the World Online (POWO), available at https://powo.science.kew.org/. Environmental data of present-day climate were obtained from CHELSA at https://chelsa-climate.org (Version 1.2). Soil bulk density data were obtained from ISRIC at https://data.isric.org/geonetwork/srv/eng/catalog.search#/metadata/2ebc3811-2783-4fb6-bb68-e8af47d32fd3 (Version 1.0). The traits data were obtained from TRY at https://www.try-db.org/ (Version 5.0).
We selected the 85 most widespread alien vascular plants in Mediterranean Europe and compiled data on their distribution in their native and invaded ranges. We then tested how a species' residence time, biogeographic origin, dispersal ability, functional traits and intraspecific trait variability (ITV) influence its niche dynamics following invasion. Using already published independent data, we finally assessed whether niche dynamics can explain different dimensions of invasion success (such as regional spread or local abundance).