IAS-pDT modelling workflow — 3. biotic data

This article details the processing of biotic data within the IAS-pDT modeling workflow. The biotic data are sourced from GBIF, EASIN, and eLTER; see below. All data preparation adheres to the FAIR principles (Findable, Accessible, Interoperable, and Reusable) to ensure scientific integrity and reproducibility.

IAS species list

The most recent checklist of naturalized terrestrial alien plant species of non-European origin was retrieved from FloraVeg.EU. This checklist was standardized against the GBIF taxonomic backbone to ensure taxonomic consistency, resulting in a total of 1,338 species. The table below summarizes the species count by taxonomic class and order. Occurrence data for these species were compiled from available sources detailed in subsequent sections.

class	order	# species	class	order	# species
Liliopsida	Acorales	2	Magnoliopsida	Gentianales	9
Liliopsida	Alismatales	9	Magnoliopsida	Geraniales	9
Liliopsida	Arecales	5	Magnoliopsida	Gunnerales	1
Liliopsida	Asparagales	75	Magnoliopsida	Lamiales	65
Liliopsida	Commelinales	4	Magnoliopsida	Laurales	1
Liliopsida	Liliales	6	Magnoliopsida	Magnoliales	1
Liliopsida	Poales	168	Magnoliopsida	Malpighiales	42
Liliopsida	Zingiberales	7	Magnoliopsida	Malvales	10
Lycopodiopsida	Selaginellales	1	Magnoliopsida	Myrtales	75
Magnoliopsida	Apiales	15	Magnoliopsida	Oxalidales	19
Magnoliopsida	Asterales	150	Magnoliopsida	Piperales	3
Magnoliopsida	Boraginales	10	Magnoliopsida	Proteales	4
Magnoliopsida	Brassicales	14	Magnoliopsida	Ranunculales	27
Magnoliopsida	Caryophyllales	144	Magnoliopsida	Rosales	124
Magnoliopsida	Celastrales	4	Magnoliopsida	Sapindales	24
Magnoliopsida	Cornales	10	Magnoliopsida	Saxifragales	38
Magnoliopsida	Cucurbitales	6	Magnoliopsida	Solanales	52
Magnoliopsida	Dipsacales	19	Magnoliopsida	Vitales	9
Magnoliopsida	Ericales	40	Pinopsida	Pinales	46
Magnoliopsida	Escalloniales	1	Polypodiopsida	Cyatheales	1
Magnoliopsida	Fabales	52	Polypodiopsida	Equisetales	1
Magnoliopsida	Fagales	20	Polypodiopsida	Polypodiales	13
Magnoliopsida	Garryales	1	Polypodiopsida	Schizaeales	1

GBIF

The GBIF_Process() function manages the retrieval, processing, and visualization of the most current occurrence data for invasive alien species (IAS) from the Global Biodiversity Information Facility (GBIF), totaling approximately 9.4 million occurrences as of March 2025. Occurrences deemed doubtful or exhibiting high spatial uncertainty are excluded to ensure data quality. Additionally, the function calculates the number of observations and occupied grid cells per species. Its primary output consists of gridded distribution maps for each species, delineating presence-only data across the reference grid.

EASIN

The European Alien Species Information Network (EASIN) serves as a web-based platform providing spatial data on approximately 14,000 alien species. The EASIN_Process() function oversees the processing and visualization of the latest IAS occurrence data sourced from EASIN. A checklist of vascular plants from EASIN’s database was retrieved via its API and standardized against the GBIF taxonomic backbone. Occurrence data for taxa corresponding to the IAS checklist were subsequently downloaded through the API. Of the 34 partner organizations contributing to EASIN (including GBIF), only non-GBIF data are incorporated into the models to avoid redundancy. Following processing and spatial filtering, the dataset includes over 420,000 observations for 466 IAS as of March 2025. Consistent with the GBIF output, the function generates gridded distribution maps for each species.

eLTER

The Integrated European Long-Term Ecosystem, Critical Zone, and Socio-Ecological Research Infrastructure (eLTER) comprises a network of sites dedicated to collecting ecological data for long-term research across the European Union. Data from 137 eLTER sites, encompassing 5,265 observations for 110 invasive alien species (IAS), were processed (eLTER_Process()) and standardized to ensure consistency with other biotic datasets in the IAS-pDT workflow.

Species distribution

The IAS_Process() function integrates and visualizes species distribution data sourced from GBIF, EASIN, and eLTER. It combines pre-processed datasets and generates presence-absence rasters for use in the species distribution models.

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↠1. Overview
↠2. Processing abiotic data
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↠4. Model fitting
↠5. Model post-processing