Map of Natura 2000 forest habitat type clusters in Flanders for the evaluation of the Minimum Dynamic Area

The cluster_habmap_msa.gpkg file is a geopackage with Natura 2000 forest habitat type clusters and is based on 'habitatmap_terr version 2023_v1' (the map of terrestrial habitat types in Flanders). It can be used to evaluate the Minimum Dynamic Area (MDA, Minimum Structuurareaal MSA in Dutch) of Natura 2000 forest habitat types. MDA is the minimum area required for a forest type to sustainably support all natural development phases without human intervention. The MDA for each forest habitat type in Flanders is specified in Oosterlynck et al. (2020). The geopackage consists of two layers: msa_2180: clusters that contain Natura habitat type 2180 (Wooded dunes) and consist of connected habitat patches of habitat types 2180, 2160 (Hippophaë rhamnoides dunes) and 91E0 (Alluvial forests). msa_91xx: clusters of connected habitat patches of all Natura 2000 forest habitat types that occur in Flanders for which the habitat code starts with '91' (9110: Luzulo-Fagetum beech forests; 9120: Beech-oak forests with Ilex; 9130: Neutrophilic beech forest; 9150: Limestone beech forests; 9160: Oak-hornbeam forests; 9190: Old oak forests; 91E0: Alluvial forests; 91F0: Riparian hardwood forests) To create the clusters, we have to take into account infrastructure that forms a physical barrier between forest patches. We used the data source GRBgis (version 2024-10-15) to select following objects: Motorways and dual carriageways from the 'Wegsegment' layer. Active railways from the 'Sbn' layer Navigable waterways from the 'Wlas' layer. The habitat clusters are created as follows: All polygons with habitat type 2160, 2180 or 91xx are selected from habitatmap_terr A buffer of 7.5 meter is created around the polygons Initial clusters are created: All buffered polygons with 2160, 2180, 91E0 habitat types that touch or intersect form the clusters in msa_2180 All buffered polygons with 91xx habitat types that touch or intersect form the clusters in msa_91xx The barrier objects are removed from the initial clusters, in some cases splitting a cluster in two separated clusters Clusters with an area smaller than 50 m² are removed (artefacts) Finally, we calculate the total area per forest type within each cluster: The total area of 2180 polygons within the msa_2180 clusters The total area for following (combinations of) habitat types or habitat subtypes within the msa_91xx clusters 9110 9120 9130 + 9150 9160 9190 91E0_va (Ash-alder gallery forests) + 91E0_vc (Ash-alder spring forests) 91E0_vm (Mesotrophic alder carrs) 91E0_vn (Eutrophic alder carrs) 91E0_vo (Oligotrophic (alder-)birch carrs) 91E0_sf (Riverine Salix forests) The calculated areas can then be compared with the MDA values in Oosterlynck et al. (2020). The MDA evaluation was part of the assessment of the Conservation Status of forest habitat types in Flanders (Vanden Borre et al., 2025) Besides the geopackage, the dataset consists of two tables containing the same information in a different format: clusters_msa.csv gives an overview of all habitatmap_terr polygons (identified by polygon_id) within each cluster (identified by cluster_id) msa.csv gives the total area for each (combination of) habitat type or habitat subtype within each cluster (identified by cluster_id) The dataset is created by the R-code in the GitHub repository 'n2khab-mhq-analysis' at commit a37b1b4. Additonal documentation of the R-code (in Dutch) is provided in the file msa_report.html. In the current version we only updated the documentation in msa_report.html. The other files remain unchanged.