Data Paper
Data Paper – Plant occurrences in Flanders and the Brussels Capital Region, Belgium
expand article infoRoosmarijn Steeman, Wouter Vanreusel, Rutger Barendse§, Filip Verloove|, Nico Wysmantel, Walter Van den Bussche, Thomas Gyselinck, Pieter Hendrickx#, Arnout Zwaenepoel¤, Pierre Van Vooren, Steven Jacobs«, Peter Desmet», Karin Gielen, Marc Herremans, Kristijn R.R. Swinnen˄
‡ Natuurpunt Studie, Coxiestraat 11, 2800 Mechelen, Belgium
§ Plantenwerkgroep Genk, 3600 Genk, Belgium
| Botanic Garden of Meise, Nieuwelaan 38, 1860 Meise, Belgium
¶ Natuurpunt, Coxiestraat 11, 2800 Mechelen, Belgium
# Natuurpunt Beheer, Coxiestraat 11, 2800 Mechelen, Belgium
¤ WVI, Baron Ruzettelaan 35, 8310 Brugge, Belgium
« University of Antwerp, Wilrijk, Belgium
» Research Institute for Nature and Forest (INBO), Kliniekstraat 25, 1070 Brussels, Belgium
˄ Evolutionary Ecology Group, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
Open Access

Abstract - Plant occurrences in Flanders and the Brussels Capital Region, Belgium is a species occurrence dataset published by Natuurpunt. The dataset contains almost 1.2 million plant occurrences of 1,222 native vascular plant species, mostly recorded by volunteers (citizen scientists), mainly since 2008. The occurrences are derived from the database, hosted by Stichting Natuurinformatie and managed by the nature conservation NGO Natuurpunt. Together with the datasets Florabank1 (Van Landuyt and Brosens 2017) and the Belgian IFBL (Instituut voor Floristiek van België en Luxemburg) Flora Checklists (Van Landuyt and Noé 2015), the dataset represents the most complete overview of indigenous plants in Flanders and the Brussels Capital Region.


native, distribution, observation, citizen science,

General description

Purpose: Plants have a long history of being recorded by both amateur and professional botanists. Volunteer data from amateur botanists were always an important source of distribution data of plants. The atlas of Flanders and the Brussels Capital region (Van Landuyt et al. 2006) was based on the teamwork of many volunteer botanists, NGOs, scientific institutes and governmental organisations. Since Natuurpunt, the largest nature conservation NGO in Flanders, Belgium, launched the web portal in 2008, the number of plant observations in Flanders and the Brussels Capital Region has risen sharply. Beside IFBL-mapping and project-related observations, this database is easily used for occasional observations and can be used for monitoring (wildlife) areas. Old notebooks and reports were screened and stored in the database (Steeman et al. 2012). The team of specialized validators motivates the inexperienced observers and validates observations. Here we publish these records on a IFBL (Instituut voor Floristiek van België en Luxemburg) grid cell resolution of 4 × 4 km².

Data published through

Source publication: This paper describes version 1.4 of this resource.

Dataset on GBIF:, DOI:

Taxonomic coverage: the taxonomic reference for the dataset is Heukels’ Flora of the Netherlands by Van der Meijden (2005) which follows the classification as suggested by the Angiosperm Phylogeny Group (APG II 2003).

General taxonomic coverage description: The datasets contains 1,222 native vascular plant (Plantae) species (as well as an additional number of subspecies, varieties, forms, hybrids and multispecies) recorded in Flanders and the Brussels Capital Region. This includes angiosperms (flowering plants), gymnosperms, ferns and allies, but not algae, mosses and lichens. If the observer remarked that the specific individual of this native plant was introduced by man, then this is recorded in the field establishmentMeans.

Taxonomic ranks

Kingdom: Plantae

Families: Adoxaceae, Alismataceae, Amaranthaceae, Amaryllidaceae, Apiaceae, Apocynaceae, Aquifoliaceae, Araceae, Araliaceae, Asparagaceae, Aspleniaceae, Asteraceae, Athyriaceae, Balsaminaceae, Berberidaceae, Betulaceae, Blechnaceae, Boraginaceae, Brassicaceae, Butomaceae, Buxaceae, Campanulaceae, Cannabaceae, Caprifoliaceae, Caryophyllaceae, Celastraceae, Ceratophyllaceae, Cistaceae, Colchicaceae, Convolvulaceae, Cornaceae, Crassulaceae, Cucurbitaceae, Cupressaceae, Cyperaceae, Cystopteridaceae, Dennstaedtiaceae, Dioscoreaceae, Droseraceae, Dryopteridaceae, Elaeagnaceae, Elatinaceae, Equisetaceae, Ericaceae, Euphorbiaceae, Fabaceae, Fagaceae, Gentianaceae, Geraniaceae, Grossulariaceae, Haloragaceae, Hydrocharitaceae, Hypericaceae, Iridaceae, Juncaceae, Juncaginaceae, Lamiaceae, Lentibulariaceae, Liliaceae, Linaceae, Lycopodiaceae, Lythraceae, Malvaceae, Marsileaceae, Melanthiaceae, Menyanthaceae, Molluginaceae, Montiaceae, Myricaceae, Nartheciaceae, Nymphaeaceae, Oleaceae, Onagraceae, Onocleaceae, Ophioglossaceae, Orchidaceae, Orobanchaceae, Osmundaceae, Oxalidaceae, Papaveraceae, Plantaginaceae, Plumbaginaceae, Poaceae, Polygalaceae, Polygonaceae, Polypodiaceae, Potamogetonaceae, Primulaceae, Ranunculaceae, Resedaceae, Rhamnaceae, Rosaceae, Rubiaceae, Ruppiaceae, Salicaceae, Santalaceae, Sapindaceae, Saxifragaceae, Scrophulariaceae, Solanaceae, Taxaceae, Thelypteridaceae, Typhaceae, Ulmaceae, Urticaceae, Verbenaceae, Violaceae, Zosteraceae

The number of records (observations) per plant species is shown in Fig. 1 and the top 10 most frequently recorded species are shown in Table 1.

Figure 1. 

The number of observations per plant species (excluding subspecies, varieties, forms, hybrids and multispecies).

Top 10 of the most frequently recorded plant species in

Scientific name Number of observations
Urtica dioica 8687
Cardamine pratensis 8446
Glechoma hederacea 7741
Quercus robur 7695
Plantago lanceolata 7438
Filipendula ulmaria 7024
Cirsium arvense 7010
Anemone nemorosa 6902
Ranunculus repens 6863
Achillea millefolium 6830

Spatial coverage

General spatial coverage: Flanders and the Brussels Capital Region (Fig. 2). These regions are situated in the north of Belgium and cover an area of 13,522 km² and 162 km² respectively (13,684 km² in total or 45% of the Belgian territory).

Figure 2. 

Location of Belgium within Europe (left) and the three administrative regions in Belgium (yellow = Flanders, black = Brussels Capital Region, red = Wallonia)

Flanders is largely covered by agricultural land (51%), urban areas (30%) and woodland (10%) while the Brussels Capital Region mainly consists of urban areas (73%), woodland (12%) and other green areas (10%) (Vriens et al. 2011). All occurrence data are generalized to IFBL grid cells of 4 × 4 km² (Fig. 3), with the grid codes indicated in the field verbatimCoordinates. The WGS84 centroids of these grid cells are calculated in decimalLatitude/Longitude with a coordinate UncertaintyInMeters of 2,828 meters (using Wieczorek et al. 2004).

Figure 3. 

4 × 4 km2 IFBL grid cells in Flanders and the Brussels capital region.

Coordinates: 50°40'48"N and 51°30'36"N Latitude; 2°32'24"E and 5°55'12"E Longitude.

We show the number of plant observations and the number of plant species per IFBL grid cell (Fig. 4). Figure 5 shows the frequency distribution of plant species per number of IFBL grid cells. The top 10 of the most widespread recorded plant species is shown in Table 2.

Figure 4. 

Left: the number of plant observations per IFBL grid cell. Red (1–200), orange (201–500), yellow (501–1000), light blue (1001–2000) and dark blue (2001–14000). Right: the number of plant species (subspecies, varieties, forms, hybrids and multispecies not included) per IFBL grid cell. Red (1–150), orange (151–300), yellow (301–450) and blue (451–600). The two white IFBL grid cells in the west of Flanders are locations without plant observations.

Figure 5. 

Known distribution based on the data from of true plant species (subspecies, varieties, forms, hybrids and multispecies not included) based on the number of IFBL grid cells with observation of this species.

Top 10 of plant species registered in the most IFBL grid cells.

Scientific name Number of IFBL grid cells
Urtica dioica 790
Achillea millefolium 777
Plantago lanceolata 772
Glechoma hederacea 765
Ranunculus repens 765
Cardamine pratensis 762
Cirsium arvense 743
Sambucus nigra 740
Tanacetum vulgare 739
Rumex obtusifolius 736

Temporal coverage: June 30, 1855 - December 31, 2016

The majority of records was collected since the launch of in 2008 (Fig. 6).

Figure 6. 

Number of collected records between 1855 and 2000 (left) and between 2001 and 2016 (right). Each number on the left x-axis is a period of 10 year (e.g., 1910 = 1901–1910, etc.). Note the difference between the scales on the y-axis between the left and right figures and the strong increase in smartphone registration of records since the launch of an app (ObsMapp for Android) in 2012.


Sampling description: Most observations (species, date, location, observer) were recorded by volunteers (citizen scientists). The dataset also includes historical records and datasets imported in The large majority of records (95%) is a casual observation (presence only record). 5% of observations were registered as part of a species checklist. This is also recorded in the field samplingProtocol. The frequency distribution of number of observers per number of records or species is shown in Fig. 7.

Figure 7. 

Frequency distribution of observers per number of observations (left) or species (right). Note the difference between the x-axis in the left and right y-axis.

Quality control description: Recorded data are verified by a group of botanical experts (including professional botanists), based on collected specimens, the observer’s species knowledge, added photographs and known species list of locations. The validation procedure from consists of an interactive procedure in which observers can be asked for additional information by a team of validators, after which the validator manually adds a validation status. Manual validation focuses on rare species, species that are reported outside their known range and observations accompanied by pictures. Records that are not manually validated are additionally checked by an automated validation procedure that takes into account the number of manually validated observations of a species within a specified date and distance range. 12% of the plant records in this dataset are supported by photographs in The validation status is indicated in the field identificationVerificationStatus, the link to the original record in references.


Dataset description

The Plant occurrences in Flanders and the Brussels Capital Region, is an export from The data were standardized to Darwin Core using a SQL query. The included terms are:

occurrenceID, type, language, license rightsHolder, accessRights, references, datasetID, institutionCode, datasetName, basisOfRecord, informationWithheld, dataGeneralizations, individualCount, sex, reproductiveCondition, establishmentMeans, samplingProtocol, eventDate, continent, countryCode, stateProvince, municipality, verbatimCoordinates, verbatimCoordinateSystem, verbatimSRS, decimalLatitude, decimalLongitude, geodeticDatum, coordinateUncertaintyInMeters, georeferenceRemarks, identificationVerificationStatus, taxonID, scientificName, kingdom, taxonRank, scientificNameAuthorship, vernacularName, nomenclaturalCode.

Generalized and/or withheld information: location information is generalized to 4 × 4 km² IFBL grid cells. Observer name, exact XY-coordinates, toponyms, and photographs are not included in the published dataset, but are stored in the source database. The dataset will be updated on GBIF on a regular basis (currently planned every two year).

Object name: - Plant occurrences in Flanders and the Brussels Capital Region, Belgium

Format name: Darwin Core Archive format

Format version: 1.0

Character encoding: UTF-8

Language: English


Usage norms:

First publication date: 2016-12-23




Since 2010, the number of plant observations registered annually is larger than all the records available in before 2008. Observations are currently mainly presence only records (95%). Presence is certain, absence of data can have multiple reasons: an IFBL grid cell was not visited, the species was not present/seen, the species was present but not registered in the database. For this reason, since the end of 2016, focusses more on lists and transect registration. During field work, the route can be tracked via the mobile app ObsMapp. At the end of the excursion, observers can indicate different types of lists, depending on whether: (1) the records are opportunistically collected presence only data (some records of some of the species encountered), (2) all individuals of selected species were registered, (3) all species were recorded or (4) all individuals of all species (more useful for animals than plants). This additional information allows to account for a better observation effort than currently is the case.

The most frequently and widespread observed plant in is Urtica dioica. This species was in Van Landuyt et al. (2006) also the most widespread plant. The other plants on the top 10 of most frequently recorded plants shows there is bias in the data collected by the plant observers of Species like Poa annua or Sagina procumbens should be seen much more than striking species like Cardamine pratensis, Filipendula ulmaria and Anemone nemorosa. This might be explained by the observers’ lack of interest in very common species (Mair and Ruete 2016). Furthermore, spatial biases are expected since the data is collected opportunistically without mandatory sampling protocol (Geldmann et al. 2016). Sampling bias related to variation in recorder activity has been grouped in four main categories by Isaac et al. (2014): 1) uneven recording intensity over time, 2) uneven spatial coverage, 3) uneven sampling effort per visit and 4) uneven detectability. We aim to understand these biases better by stimulating the use of species lists rather than the collection of presence only data.


We thank the editor and reviewer for significant improvements to the manuscript. We thank all plant working groups and plant observers for their efforts to record plant observations all over Flanders and the Brussels Capital Region.


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