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Meetnetten.be - Larvae and metamorph counts for Amphibia in Flanders, Belgium

Version 1.9 published by Research Institute for Nature and Forest (INBO) on Oct 28, 2020 Research Institute for Nature and Forest (INBO)

Meetnetten.be - Larval and metamorph counts for Amphibia in Flanders, Belgium is a sampling event dataset published by the Research Institute of Nature and Forest (INBO). It is part of the Meetnetten.be suite of monitoring networks for priority species in Flanders, in which data are collected at fixed locations using a standardized protocol (https://meetnetten.be). This dataset contains site counts for 3 priority species (Triturus cristatus, Hyla arborea, Pelobates fuscus), as well as other amphibian species observed during sampling. 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), maximum depth, number of sweeps, pH, presence of fish, shading, pond surface, permanent water column and water quality at the time of the event (in the measurement or fact extension) and for each occurrence an 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/meetnetten-occurrences/issues

Generalized and/or withheld information: as these are sensitive priority species, location information is generalized to 1, 5 or 10 km Universal Transverse Mercator (UTM) grid cells. Original locations are available upon request.

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.

For all published Meetnetten.be datasets, see https://www.gbif.org/dataset/search?project_id=meetnetten.be

Data Records

The data in this sampling event resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 154 records. 2 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.

  • Event (core)
  • MeasurementOrFact 
  • Occurrence 

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.


Download the latest version of this resource data as a Darwin Core Archive (DwC-A) or the resource metadata as EML or RTF:

Data as a DwC-A file download 154 records in English (20 KB)  - Update frequency: annually
Metadata as an EML file download in English (19 KB)
Metadata as an RTF file download in English (17 KB)


The table below shows only published versions of the resource that are publicly accessible.

How to cite

Please be aware, this is an old version of the dataset.  Researchers should cite this work as follows:

Piesschaert F, Speybroeck J, Brosens D, Westra T, Desmet P, Ledegen H, Van de Poel S, Pollet M (2020): Meetnetten.be - Larvae and metamorph counts for Amphibia in Flanders, Belgium. v1.9. Research Institute for Nature and Forest (INBO). Dataset/Samplingevent. https://ipt.inbo.be/resource?r=meetnetten-amfibieen-larven-metamorfen-occurrences&v=1.9


Researchers should respect the following rights statement:

The publisher and rights holder of this work is Research Institute for Nature and Forest (INBO). To the extent possible under law, the publisher has waived all rights to these data and has dedicated them to the Public Domain (CC0 1.0). Users may copy, modify, distribute and use the work, including for commercial purposes, without restriction.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: 89d08c4f-4727-45be-83d4-1fd96ddee81d.  Research Institute for Nature and Forest (INBO) publishes this resource, and is itself registered in GBIF as a data publisher endorsed by Belgian Biodiversity Platform.


Occurrence; Salamanders; frogs; newt; freshwater; monitoring; priority species


Who created the resource:

Frederic Piesschaert
Research Institute for Nature and Forest (INBO) BE
Jeroen Speybroeck
Research Institute for Nature and Forest (INBO) BE
Dimitri Brosens
Research Institute for Nature and Forest (INBO)/ Belgian Biodiversity Platform BE
Toon Westra
Research Institute for Nature and Forest (INBO) BE
Peter Desmet
Research Institute for Nature and Forest (INBO) BE
Hannes Ledegen
Sam Van de Poel
Marc Pollet
Research manager
Research Institute for Nature and Forest (INBO) BE

Who can answer questions about the resource:

Frederic Piesschaert
Research Institute for Nature and Forest (INBO) BE

Who filled in the metadata:

Dimitri Brosens
Research Institute for Nature and Forest (INBO) / Belgian Biodiversity Platform BE
Peter Desmet
Research Institute for Nature and Forest (INBO) BE

Who else was associated with the resource:

Peter Desmet

Geographic Coverage

Flanders, Belgium

Bounding Coordinates South West [50.67, 2.53], North East [51.51, 5.94]

Taxonomic Coverage

The target species for Meetnetten.be are listed at https://meetnetten.be/#group-1. Other salamanders observed during the sampling are also included. This dataset covers the amphibian fyke protocol, for which there are 3 target species.

Kingdom  Animalia
Phylum  Chordata
Class  Amphibia
Order  Caudata
Species  Triturus cristatus (great crested newt),  Hyla arborea (common tree frog),  Pelobates fuscus (common spadefoot toad)

Temporal Coverage

Start Date / End Date 2016-01-01 / 2019-12-31

Project Data

Meetnetten.be is a suite of monitoring networks through which the Flemish Government is collecting high-quality information on 65 priority plant and animal species. These are species on which Flanders has to report to Europe in the framework of the Habitats and Birds Directives, but also other species that are important for the Flemish nature policy.

Title Meetnetten.be
Identifier meetnetten.be
Funding Flemish Government
Study Area Description Flanders, Belgium
Design Description Each monitoring network consists of fixed sample locations in which target species are counted based on a standardized protocol. Data collection relies mainly on specialized volunteers, coordinated by the NGO Natuurpunt Studie. Fieldwork is planned and monitored with the web tool https://meetnetten.be, which is also used for entering the collected data.

The personnel involved in the project:

Point Of Contact
Frederic Piesschaert

Sampling Methods

In June - mid-July, larvae are counted to determine reproductive success. In order to quantify the larvae present, a net should be dipped per 2 m of shoreline (where possible and suitable). Each two-metre piece (one dip movement), the number of larvae is noted. In total, you feed a minimum of 5 and a maximum of 30 scoop movements. Sampling was done using the protocol described in De Bruyn et al. (2015), updated by Speybroeck et al. (2020), and explained to volunteers in Lewylle et al. (2017).

Study Extent 1. Triturus cristatus, or the great crested newt, is our largest native newt. It is widespread in Flanders, especially in wide river valleys and in locations with (many) old bomb pits. Although the crested newt appears to react positively to the construction of new pools near existing populations in nature reserves, it seems to be declining in the outlying area. This species prefers fish-free pools with sun-drenched banks and rich underwater vegetation located in a varied terrestrial habitat. These include cattle drinking pools in meadows with many small landscape elements, large (spring) pools in more wooded habitats, cut-off rivers, but also old quarries. 2. Pelobates fuscus, or the common spadefoot toad, is found in fishless cattle drinking pools and relatively nutrient-rich ponds, but also in cut brook and river meanders in a fairly open, sandy environment. These are often water features in (buffered) heathlands, but also near dikes and even vegetable gardens and extensively managed fields. This type of habitat is rare in Flanders. The common spadefoot currently only occurs in the central part of Limburg. 3. Hyla arborea, or the common tree frog, is found in the scrubland of the Limburgse Kempen, a restricted section of the Antwerpse Kempen near the Belgian-Dutch border, and the dunes of the Zwin. In recent years, the Flemish population has increased.
Quality Control Data are collected using a predefined sampling protocol.

Method step description:

  1. Researchers from INBO and Natuurpunt Studie define and document the appropriate sampling protocol for the target species.
  2. Fieldwork is planned and coordinated by Natuurpunt Studie, using https://meetnetten.be.
  3. Data are collected in the field by specialized volunteers, using the predefined sampling protocol.
  4. Volunteers enter the collected data in https://meetnetten.be.
  5. A custom SQL view is created in the meetnetten.be database to map the original data to Darwin Core as an event core with an occurrence extension
  6. The Darwin Core views are connected to the INBO IPT and documented with metadata.
  7. The dataset is published and registered with GBIF.

Bibliographic Citations

  1. De Bruyn L, Speybroeck J, Maes D, De Knijf G, Onkelinx T, Piesschaert F, Pollet M, Truyens P, Van Calster H, Westra T, Quataert P (2015). Monitoringsprotocol kamsalamander. Rapporten van het Instituut voor Natuur- en Bosonderzoek 2015 (INBO.R.10186543). Instituut voor Natuur- en Bosonderzoek, Brussel. INBO.R.10186543
  2. Lewylle I. & H. Ledegen. 2017. Veldwerkhandleiding Kamsalamander. Natuurpunt Studie, Mechelen
  3. Speybroeck J, De Bruyn L, Van de Poel S, Ledegen H, Westra T (2020). Monitoringsprotocol amfibieën en reptielen. Versie 2.0. Rapporten van het Instituut voor Natuur- en Bosonderzoek 2020 (22). Instituut voor Natuur- en Bosonderzoek, Brussel. https://doi.org/10.21436/inbor.17954118

Additional Metadata

Alternative Identifiers 89d08c4f-4727-45be-83d4-1fd96ddee81d