The Global Register of Introduced and Invasive Species - Belgium is a species checklist published by the Invasive Species Specialist Group (ISSG). It contains information on 3,900+ validated non-native taxa in Belgium and serves as the national reference for the Global Register of Introduced and Invasive Species (GRIIS, Pagad et al. 2018). The checklist is created through an open and reproducible workflow developed for the TrIAS project (http://trias-project.be, see Methodology). It is published here as a standardized Darwin Core Archive and includes for each taxon: the scientific name, higher classification and stable taxon identifier, provided by the GBIF Backbone Taxonomy (in the taxon core) and related information in three extensions, provided by the source checklists (or the most trustworthy one in case of competing information). The related information consists of the year of first introduction and last assessment/observation in Belgium and where available its regions (given as a year range in the event date in the distribution extension), coarse habitat information (in the species profile extension) and the pathway(s) of introduction, native ranges (following UN geoscheme), and invasion stage in Belgium (in the description extension). The source for each piece of information is credited. Issues with the dataset can be reported at https://github.com/trias-project/unified-checklist We have released this dataset under a Creative Commons Attribution 4.0 International License (CC-BY 4.0). We would appreciate it if you follow the GBIF citation guidelines (https://www.gbif.org/citation-guidelines) when using the data. If you have any questions regarding this dataset, don’t hesitate to contact us via the contact information provided in the metadata or via https://twitter.com/trias_project. This dataset was published as open data for the TrIAS project (Tracking Invasive Alien Species http://trias-project.be, Vanderhoeven et al. 2017), with technical support provided by the Research Institute for Nature and Forest (INBO).

The checklist of alien herpetofauna of Belgium is a species checklist dataset published by the Research Institute for Nature and Forest (INBO). It contains information on alien amphibian and reptile species recorded in the wild in Belgium since 1968. Both established species and occasional records are included, but with information on the degree of establishment of species following the unified invasion framework of Blackburn et al. (2011). The checklist is published here as a standardized Darwin Core Archive and includes for each (sub)species: the scientific name and classification (in the taxon core), the presence in Flanders, Wallonia and the Brussels-Capital Region, year of first and last observation in Belgium (given as a year range in the event date in the distribution extension), coarse habitat information (in the species profile extension), and the degree of establishment, pathway(s) of introduction and native range(s) (in the description extension). Issues with the dataset can be reported at https://github.com/trias-project/alien-herpetofauna-belgium. We have released this dataset to the public domain under a Creative Commons Zero waiver. We would appreciate it if you follow the GBIF citation guidelines (https://www.gbif.org/citation-guidelines) when using the data. If you have any questions regarding this dataset, don’t hesitate to contact us via the contact information provided in the metadata or via https://twitter.com/trias_project. This dataset was published as open data for the TrIAS project (Tracking Invasive Alien Species http://trias-project.be, Vanderhoeven et al. 2017), with technical support provided by the Research Institute for Nature and Forest (INBO). It is selected as one of the authoritative sources for the compilation of a unified and reproducible checklist of alien species in Belgium.

The Checklist of non-native freshwater fishes in Flanders, Belgium is a species checklist dataset published by the Research Institute for Nature and Forest (INBO). It contains information on 23 alien fish species occurring in Flemish natural and semi-natural waterbodies, detected in sampling between 1992 and 2006. This species checklist was assessed within the framework of the Freshwater Fish Monitoring Network by Verreycken et al. (2007) and reassessed for Verreycken et al. (2018). Here it is published as a standardized Darwin Core Archive and includes for each species: the scientific name, kingdom, and stable taxon identifier (in the taxon core), the Dutch and English vernacular name (in the vernacular names extension), the year of first introduction in Flanders (given as a year range, with the year of last observation empty), the pathway(s) of introduction and the degree of establishment in Flanders (in the distribution extension), coarse habitat information (in the species profile extension) and native range(s) (in the description extension). The dataset can be used for researching and managing aquatic invasions or compiling regional and national registries of alien species. Issues with the dataset can be reported at: https://github.com/trias-project/alien-fishes-checklist We have released this dataset to the public domain under a Creative Commons Zero waiver. We would appreciate it if you follow the the INBO norms for data use (https://www.inbo.be/en/norms-data-use) when using the data. If you have any questions regarding this dataset, don’t hesitate to contact us via the contact information provided in the metadata or via https://twitter.com/LifeWatchINBO. This dataset was published as open data for the TrIAS project (Tracking Invasive Alien Species http://trias-project.be, Vanderhoeven et al. 2017), with technical support provided by the Research Institute for Nature and Forest (INBO). It is selected as one of the authoritative sources for the compilation of a unified and reproducible checklist of alien species in Belgium.

Waarnemingen.be / observations.be - List of species observed in Belgium is a species checklist dataset published by Natuurpunt and Natagora. Waarnemingen.be (in Dutch) and observation.be (in French) are the two local Belgian subsites of the global observation.org website. The checklist comprises 18.785 species observed in Belgium. Here, it is published as a standardized Darwin Core Archive and includes for each species: the scientific name, higher classification and stable taxon identifier (in the taxon core), its status (native, introduced) and first and last observation date per region (Flanders, Brussels Capital Region, Wallonia) in Belgium (in the distribution extension). Only observations which were approved by species specialists based on provided evidence (photograph or sound), or which were approved based on expert judgment by the validating experts were considered for publication (see Swinnen et al. 2022 for the validation procedure). Observers’ data-sharing settings were respected at all times. When the first or last observation from a species in a region was not to be shared, observers were contacted to request an exception for this species list. In the few cases this authorisation was not acquired, the next (for the oldest record) or previous (for the most recent record) observation date was considered for publication. This species list does not represent a complete overview of Belgian biodiversity, only species that are recorded in the citizen science platforms waarnemingen.be and observation.be. Other datasets and checklists have to be considered for the compilation of a complete Belgian overview. We have released this dataset under a Creative Commons Attribution 4.0 International License (CC-BY 4.0). We would appreciate it, however, if you read and follow these norms for data use (http://www.natuurpunt.be/normen-voor-datagebruik). If you use these data for a scientific paper, please cite the dataset following the applicable citation norms and/or consider us for co-authorship. We are always prepared to provide more information or knowledge on how to use the data, so please contact us via the contact information provided in the metadata or natuurdata@natuurpunt.be. This dataset was published as open data for the TrIAS project (Tracking Invasive Alien Species http://trias-project.be, Vanderhoeven et al. 2017, Groom et al. 2022), with technical support provided by the Research Institute for Nature and Forest (INBO). The subset of introduced species is selected as one of the authoritative sources for the compilation of a unified and reproducible checklist of alien species in Belgium published as the Global Register of Introduced and Invasive Species - Belgium (Desmet et al. 2021). This way, validated newly reported alien species on the waarnemingen.be/observation.be citizen science portal (Swinnen et al. 2018) quickly find their way to the scientific tools supporting alien species policies and management in Belgium.

The checklist of alien parrot species in Turkey is a species checklist dataset managed by the Gazi University. It was developed particularly for the Turkish parakeet census project (trpapagansayimlari.blogspot.com), and it includes newly introduced parrot species not covered elsewhere (yet). Here it is published as a standardized Darwin Core Archive and includes for each species: the scientific name, higher classification and stable taxon identifier (in the taxon core), the presence status, date of first collection and last observation (given as a year range in the event date) and degree of establishment of the species in Turkey in the distribution extension. Issues with the dataset can be reported at esraper@gazi.edu.tr We have released this dataset to the public domain under a Creative Commons Zero waiver. We would appreciate it if you follow the GBIF citation guidelines (https://www.gbif.org/citation-guidelines) when using the data. If you have any questions regarding this dataset, don't hesitate to contact us via the contact information provided in the metadata or via e-mail.

Non-native Fish in Flanders, Belgium is a sampling event dataset published by the Research Institute of Nature and Forest (INBO). It is part of the VIS database in which data are collected to monitor the status of fishes and their habitats in Flanders,. This dataset contains fish counts of exotic fish in Flanders. Here, it is published as a standardized Darwin Core Archive and includes for each sampling event an eventID, date, location and sampling protocol (in the event core) and for each occurrence and occurrenceID, the number of recorded individuals, status (present/absent) and scientific name (in the occurrence extension). Issues with the dataset can be reported at https://github.com/inbo/data-publication/issues We have released this dataset to the public domain under a Creative Commons Zero waiver. We would appreciate it if you follow the INBO norms for data use (https://www.vlaanderen.be/inbo/en-gb/norms-for-data-use/) when using the data. If you have any questions regarding this dataset, don't hesitate to contact us via the contact information provided in the metadata or via opendata@inbo.be. For all published VIS datasets occurrences, see https://www.gbif.org/occurrence/search?collection_code=VIS

The Checklist of alien species in the Scheldt estuary in Flanders, Belgium is a species checklist dataset published by the Research Institute for Nature and Forest (INBO). It contains information on 61 invertebrate alien species occurring in the Belgian Scheldt estuary, detected between 1835 and now. Here it is published as a standardized Darwin Core Archive and includes for each species: the scientific name, higher taxonomy, stable taxon ID (in the taxon core), the year of first introduction and/or last assessment in Flanders (given as a year or year range in the event date in the distribution extension), coarse habitat information (in the species profile extension) and the native range(s), pathway(s) of introduction and degree of establishment in Flanders (in the description extension). Issues with the dataset can be reported at https://github.com/trias-project/alien-scheldt-checklist We have released this dataset to the public domain under a Creative Commons Zero waiver. We would appreciate it if you follow the INBO norms for data use (https://www.inbo.be/en/norms-data-use) when using the data. If you have any questions regarding this dataset, don't hesitate to contact us via the contact information provided in the metadata or via opendata@inbo.be. This dataset was published as open data for the TrIAS project (Tracking Invasive Alien Species http://trias-project.be, Vanderhoeven et al. 2017), with technical support provided by the Research Institute for Nature and Forest (INBO). It is selected as one of the authoritative sources for the compilation of a unified and reproducible checklist of alien species in Belgium.

Invasive species - Chinese muntjac (Muntiacus reevesi) in Flanders, Belgium is a sampling event dataset published by the Research Institute of Nature and Forest (INBO). It contains information on 120 sampling events with 64 validated occurrences of invasive muntjac (M. reevesi) and native roe deer (Capreolus capreolus) starting from 2004. These occurrences mainly originate from casual observations or cullings of individuals. Here the dataset is published as a standardized Darwin Core Archive and includes for each event: a stable eventID, date and location of observation, and a short description of the sampling protocol (in the event core), supplemented with specific information for each occurrence: a stable occurrenceID, the scientific name and higher classification of the observed species, the number of recorded individuals, sex, life stage, and a reference to the observer and identifier of the record (in the occurrence extension). Issues with the dataset can be reported at https://github.com/inbo/data-publication/issues We have released this dataset to the public domain under a Creative Commons Zero waiver. We would appreciate it if you follow the INBO norms for data use (https://www.inbo.be/en/norms-data-use) when using the data. If you have any questions regarding this dataset, don't hesitate to contact us via the contact information provided in the metadata or via opendata@inbo.be. This dataset was published as open data for the TrIAS project (Tracking Invasive Alien Species http://trias-project.be, Vanderhoeven et al. 2017), with technical support provided by the Research Institute for Nature and Forest (INBO).

Invasive species - Ruddy duck (Oxyura jamaicensis) in Flanders, Belgium is a sampling event dataset published by the Research Institute of Nature and Forest (INBO). It contains information on 107 sampling events with 88 validated occurrences of invasive ruddy duck (with 2 extra occurrences reporting on white-headed duck) starting from 2009. These occurrences mainly originate from observations or cullings (through shooting or trapping) of individuals associated with official control actions in Flanders, North Belgium in response to the Bern Convention Action Plan on ruddy duck eradication (Robertson et al. 2015; Bern Convention 2016; Hall 2016). The data are used for feeding the Flemish biodiversity indicator on the progress of ruddy duck eradication. Also, they are used for official reporting to the Bern Convention Action Plan on the eradication of ruddy duck from the Western Palearctic (Bern Convention 2016; Hall 2016) and, as the species is included in the list of invasive species of Union Concern since 2016, for reporting to the EU IAS Regulation (1143/2014) (European Union 2014). The data are also used for research purposes. Here the dataset is published as a standardized Darwin Core Archive and includes for each event: a stable eventID, date and location of observation, and a short description of the sampling protocol (in the event core), supplemented with specific information for each occurrence: a stable occurrenceID, the scientific name and higher classification of the observed species, the number of recorded individuals, sex, life stage, and a reference to the observer and identifier of the record (in the occurrence extension). Issues with the dataset can be reported at https://github.com/inbo/data-publication/issues We have released this dataset to the public domain under a Creative Commons Zero waiver. We would appreciate it if you follow the INBO norms for data use (https://www.inbo.be/en/norms-data-use) when using the data. If you have any questions regarding this dataset, don't hesitate to contact us via the contact information provided in the metadata or via opendata@inbo.be. This dataset was published as open data for the TrIAS project (Tracking Invasive Alien Species http://trias-project.be, Vanderhoeven et al. (2017)), with technical support provided by the Research Institute for Nature and Forest (INBO).

An inventory was made of the alien macroinvertebrates occurring in Flanders. To this end large collections of biological samples were investigated and supplemented with own sampling campaigns. Mainly fresh and brackish surface waters were investigated. Three new macroinvertebrate species for Flanders were discovered. In total 41 alien macroinvertebrates were encountered in fresh and slightly brackish surface waters in Flanders. Additionally, 24 alien macroinvertebrate species have been reported for the Belgian part of the North Sea and its adjacent estuaries. Most alien macroinvertebrates belonged to the crustaceans and molluscs. Over 2,500 samples containing macrocrustaceans were identified to species level, which allowed us to accurately map their distribution in Flanders. Alien species found in the fresh and brackish water environment, mainly originated from the Ponto-Caspian area and North-America followed by Asia and South- and East-Europe. This overview shows that alien macroinvertebrates are widespread and abundantly present in many watercourses in Flanders. Based on observations in neighbouring countries, several additional species are expected to arrive in the near future. A follow-up of the invasive alien species together with a monitoring scheme to detect new incoming species is valuable to estimate the size of the problem and to be able to closely follow their ecological and economic impact This dataset was originally created for research on the spread and impact of alien invasive macroinvertebrate species in Flanders. However, the dataset can be reused for a variety of purposes. However, this being an occurrence dataset, it can be used for understanding species richness, distribution pattern and modelling studies such as ecological niche modelling. In order to enhance the confidence of use, we have documented the metadata as well as subjected the data records to a series of quality assessment and enhancement processes as described in the earlier section quality control description. To allow anyone to use this dataset, we have released the data to the public domain under a Creative Commons Zero waiver (http://creativecommons.org/publicdomain/zero/1.0/). We would appreciate however, if you read and follow these norms for data use (http://www.inbo.be/en/norms-for-data-use) and provide a link to the original dataset (https://doi.org/10.15468/xjtfoo) whenever possible. If you use these data for a scientific paper, please cite the dataset following the applicable citation norms and/or consider us for co-authorship. We are always interested to know how you have used or visualized the data, or to provide more information, so please contact us via the contact information provided in the metadata, opendata@inbo.be or https://twitter.com/LifeWatchINBO.