Meetnetten.be - Population counts of priority vascular plants species in Flanders, Belgium

Study Extent

Gentianella uliginosa Duingentiaan Dune Gentian is a species of sunny places on moist to wet, nutrient-poor, alkaline, calcareous and slightly humid soil. The species grows mainly in coastal sand dunes (grey dunes and dune slacks). Dune Gentian is very rare in Flanders and is only known from the coastal dunes area. Bupleurum tenuissimum Fijn goudscherm Slender Hare's-ear Slender Hare's-ear is a species of sunny, open, grassy sites on dry to moist, brackish soil. The species is in Flanders only known from the Zwin dunes, where it was rediscovered in 2011. Previously the species was considered extinct in Flanders. Orobanche rapum-genistae Grote bremraap Greater Broomrape is a species of sunny places on dry, nutrient-poor, weakly acid sandy soil with open or shrubby vegetation. The species is parasitic on Common Broom. The species has become very rare in Flanders and is mostly limited to the Flemish district and the Campine district. Orchis morio Harlekijn Green-winged Orchid is a species of sunny sites on moist,nutrient-poor, unfertilised, neutral to calcareous soil. The species was known from nutrient poor grasslands inland as well as moist coastal dune grasslands. Green-winged Orchid is very rare in Flanders, there are only a few localities left inland where only small populations survive. In 2015 one specimen was again spotted in a coastal dune slack, where the species had not been seen for more than 30 years. Unfortunately, the species disappeared here again after 2 years. Herminium monorchis Honingorchis Musk Orchid is a species of sunny sites on moist to fairly wet, nutrient-poor, calcareous soils. In Flanders, it is a species of coastal dune slacks. In Flanders, the musk orchid is rare and has declined considerably. It is only known from the dunes near De Panne, Koksijde and Oostduinkerke. Scorzonera humilis Kleine schorseneer Dwarf Viper's-grass is a species of sunny, rarely slightly shaded sites on dry, nutrient-poor, weakly acid soil. It is a species of Molinia meadows. Dwarf Viper's-grass is very rare in Flanders and only known from the Brabant district and the Campine district. Diphasiastrum tristachyum Kleine wolfsklauw Blue Clubmoss is a plant of sunny, open places on nutrient-poor, acid sandy soil. The species grows on heathlands and in open woodland patches, but in Flanders it is only recently known from three places, all in dry heathlands. Juncus capitatus Koprus Dwarf Rush is a species of sunny to slightly shaded, open pioneer vegetation on moist to wet, moderately nutrient-poor, slightly acidic, whether or not humid sand or loamy soil. The species was extinct in Flanders but was rediscovered in 2008 after work in the Dassenaarde nature reserve, where it emerged from the seed bank in large numbers. Meanwhile, this locality is becoming overgrown and the population size is decreasing. Stratiotes aloides Krabbenscheer Water Soldier is a species of sunny, sheltered places in shallow, stagnant or slowly flowing, moderately nutrient-rich to nutrient-rich, fresh water with a bottom of peat, river clay or sand. Natural populations of this species are very rare in Flanders, but the species is also often (illegally) introduced, also outside its original range. Orchis purpurea Purperorchis Lady Orchid is a species of open to moderately shaded sites on moist to dry, nutrient-poor, on open calcareous grasslands and along forest edges. For Flanders the species is only known from Haspengouw and the Voerstreek. Hammarbya paludosa Veenmosorchis Bog Orchid is a species of sunny, fairly open places on wet, nutrient-poor, acidic peat. The species can grow in fens and bogs. It is very rare in the Kempen region, where it is only known from the Buitengoor in Mol. Platanthera bifolia Welriekende nachtorchis Lesser Butterfly-orchid is a species of sunny to semi-shaded locations on moist, nutrient-poor, unfertilized, humus-rich, slightly acidic to calcareous soil. It grows on more acidic soils than Greater Butterfly-orchid and can be found in grassy heaths, sparse grasslands, open places in forests or shrubs.

Sampling

Sampling was done using the protocol described in Van Landuyt et al. (2019) and explained to volunteers in Ledegen et al. (2017). To estimate population size, the Floron scale is used. For each growth site, depending on the species, you estimate the numbers or area using 6 categories. A = 1; B = 2-5; C = 6-25; D = 26-50; E = 51-500; F = 501-5000 Each growth site should be viewed once every 3 years. Gentianella uliginosa ;Diphasiastrum tristachyum Counting method: estimation of the number of individuals of Dune gentian per growth site from July till September. Bupleurum tenuissimum Counting method: Estimation of the number of individuals of Slender hare's-ear per growing site from June to September.
Orobanche rapum-genistae; Orchis morio; Scorzonera humilis; Orchis purpurea Counting method: estimate the number of individuals per growth site in May and June.
Platanthera bifolia; Herminium monorchis Counting method: estimate of the number of individuals in June and July.
Juncus capitatus Counting method: Estimation of the number of individuals of dwarf rush per growing site from June to August.
Stratiotes aloides Counting method: estimation of the number of individuals of water soldiers per growing site in August and September. For water soldiers, binoculars can be used to estimate population. Hammarbya paludosa Counting method: Estimation of the number of individuals of Bog Orchid per habitat in July and August.

Quality Control

Data are collected using a predefined sampling protocol.

Method steps

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 is 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, occurrence extension and measurement or fact 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.

The target plant species for Meetnetten.be are listed athttps://meetnetten.be/#group-5. Other plants observed during the sampling are also included. This dataset covers the plant surface protocol, for which there are 11 target species.

1. Plantae
   rank: kingdom
2. Tracheophyta
   rank: phylum
3. Gentianella uliginosa
4. Bupleurum tenuissimum
5. Orobanche rapum-genistae
6. Orchis morio
7. Herminium monorchis
8. Scorzonera humilis
9. Diphasiastrum tristachyum
10. Juncus capitatus
11. Stratiotes aloides
12. Orchis purpurea
13. Hammarbya paludosa
14. Platanthera bifolia

Flanders, Belgium