IASDT modelling workflow — 3. biotic data

This article details the processing of biotic data within the IASDT modelling 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 naturalised 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 1,319 species (September, 2025). The table below summarises 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	8	Magnoliopsida	Geraniales	9
Liliopsida	Arecales	5	Magnoliopsida	Gunnerales	1
Liliopsida	Asparagales	74	Magnoliopsida	Lamiales	63
Liliopsida	Commelinales	4	Magnoliopsida	Laurales	1
Liliopsida	Liliales	6	Magnoliopsida	Magnoliales	1
Liliopsida	Poales	163	Magnoliopsida	Malpighiales	41
Liliopsida	Zingiberales	7	Magnoliopsida	Malvales	10
Lycopodiopsida	Selaginellales	1	Magnoliopsida	Myrtales	74
Magnoliopsida	Apiales	15	Magnoliopsida	Oxalidales	19
Magnoliopsida	Asterales	148	Magnoliopsida	Piperales	3
Magnoliopsida	Boraginales	10	Magnoliopsida	Proteales	4
Magnoliopsida	Brassicales	13	Magnoliopsida	Ranunculales	27
Magnoliopsida	Caryophyllales	141	Magnoliopsida	Rosales	125
Magnoliopsida	Celastrales	4	Magnoliopsida	Sapindales	23
Magnoliopsida	Cornales	10	Magnoliopsida	Saxifragales	38
Magnoliopsida	Cucurbitales	6	Magnoliopsida	Solanales	51
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	12
Magnoliopsida	Garryales	1	Polypodiopsida	Schizaeales	1

GBIF

The gbif_process() function manages the retrieval, processing, and visualisation of the most current occurrence data for invasive alien species (IAS) from the Global Biodiversity Information Facility (GBIF), totalling approximately 10.4 million occurrences as of September 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 visualisation 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 427K observations for 465 IAS as of September 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. Cleaned standardised data encompassed 4K observations for 109 IAS (September 2025). The elter_process() function processed standardised eLTER data in a format ready to be used in the models.

Species distribution

The naps_process() function integrates and visualises 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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Previous articles:
↠1. Overview
↠2. Processing abiotic data
Next articles:
↠4. Model fitting
↠5. Model post-processing