Meetnetten.be - Occupancy estimates of priority vascular plants species in Flanders, Belgium

Study Extent

To estimate the local population size, the Floron scale is used. For each species patch, volunteers estimate the numbers or the species patchusing 6 categories. A < 1m²; B = 1-5m²; C = >5-25m²; D = >25-50m² ; E = >50-500m²; F = >500-5000m² Potamogeton coloratus Weegbreefonteinkruid Plantain Pondweed is a species of sunny, sometimes slightly shaded places in very clear, shallow, moderately nutrient-poor to moderately nutrient-rich, calcareous water. The species is very rare in Flanders, it is only known from a few places in the coastal dunes, the vicinity of the community of Kampenhout, the Visbeek Valley and the nature reserve Walenbos.
Utricularia ochroleuca Bleekgeel blaasjeskruid Yellowishwhite Bladderwort (Utricularia ochroleuca) is a species found in sunny places in shallow, nutrient-poor, weakly to moderately acidic water, in moorland bogs and peat ponds. The species is extinct in Flanders. Ranunculus ololeucos Witte waterranonkel White-flowered Buttercup is a species found at sunny sites, in shallow, stagnant, moderately nutrient-poor to moderately nutrient-rich, unpolluted, acidic, very soft, clear water, but also on summer-dry sites. The soil usually consists of peaty sand, sand orloamy sand. The species is in sharp decline in Flanders and is very rare in the Campine region and has disappeared or is extremely rare elsewhere. Mentha pulegium Polei Pennyroyal is a species found on sunny sites on moist to wet, winter-flooded, moderately nutrient-rich to nutrient-rich, disturbed soil. The species prefers places with a varying water table or trampled or grazed areas. In Flanders, only natural locations of Pennyroyal are known along the Meuse River, elsewhere in Flanders the species was introduced. Wahlenbergia hederacea Klimopklokje Ivy-leaved Bellflower is a species found on sunny to semi-shadedsites on moist to wet, moderately nutrient-poor, slightly acidic, lime-poor soil (peat and sand). It is a species of wet, peaty heathland and peat bogs, sometimes with a management of sod cutting. Ivy-leaved Bellflower is very rare in Flanders and only known from the Campine region. Deschampsia setacea Moerassmele Bog Hair-grass grows in sunny places on wet, nutrient-poor to moderately nutrient-rich, weakly acidic, lime-poor soil (loamy sand, possibly covered with a thin layer of peat), with supply of base-rich groundwater and gradients. The species is very rare in the Kempen region and has declined significantly in recent decades. Potamogeton acutifolius Spits fonteinkruid Sharp-leaved Pondweed grows in sunny places in shallow, stagnant or weakly flowing, moderately nutrient-rich to nutrient-rich, but not polluted, fresh and neutral to often calcareous water with a muddy, organic soil (clay and sand, not on loam). This species is very rare in Flanders. It is most often seen in the Kempen region and the Sand and Sandy Loam region, but has declined sharply. Scirpus pungens Stekende bies Sharp Club-rush is a species of sunny, fairly open sites on wet, moderately nutrient-rich, saline or sometimes desalinated sandy soils. It is a species of water edges (silty banks, at the transition between bank thickets and cultivated land), high salt marshes, brackish reed land marshes, shallow water and grassy grasslands on sandbanks with fresh seepage. The species is very rare in Flanders with only a few growth sites along the river Scheldt.
Halimione pedunculata Gesteelde zoutmelde Annual Sea Purslane is a species of sunny, more or less open places on fairly dry to usually wet, moderately nutrient-rich to nutrient-rich, salty sandy soil. It is a species of places with a strongly varying salt content, which are now and then briefly inundated by seawater. In Flanders this species is only known from the Zwin dunes, near Ostend. Potamogeton compressus Plat fonteinkruid Grass-wrack Pondweed is a species of sunny sites in shallow, moderately nutrient-poor to nutrient-rich, usually unpolluted, weakly acidic to neutral, stagnant water with a bottom of low peat, venous river clay or sand. Often in places with seepage or rising groundwater. In Flanders the species is rare and is only found in the Kempen and the sand and sandy loam region.
Scirpus triqueter Driekantige bies Triangular Club-rush is a species of sunny, open places in shallow, nutrient-rich water with a bottom of sand or soft silt and also grows on silt-covered rocky dike embankments. The species appears mostly in places that flood twice a day, where weakly brackish water meets fresh water. The species is very rare along the Scheldt and has declined significantly. Triangular rush is difficult to distinguish from Rough rush and Rough rush x Triangular rush. Carex diandra Ronde zegge Lesser Tussock-sedge is a species of sunny places on wet, moderately nutrient-poor, weakly acidic to calcareous soils with fairly stable water levels and also grows in stagnant, usually very shallow, fresh, moderately nutrient-poor, weakly acidic water. The species is very rare in Flanders and only grows in the Kempen. Eriophorum gracile Slank wollegras Slender Cottongrass is a species of sunny sites on wet, nutrient-poor, weakly acidic, iron-rich peat soil. The plant is very sensitive to fertilization and/or acidification. The species is very rare in Flanders and only grows in the Kempen.

Sampling

Sampling was done using the protocol described in Van Landuyt et al. (2015) and explained to volunteers in Ledegen et al. (2017). For Potamogeton coloratus, Utricularia ochroleuca, Wahlenbergia hederacea, Potamogeton acutifolius, Scirpus pungens Counting method: estimation of the occupancy in the growth area per m² from June to August. Each area has to be surveyed once every 3 years. The Floron scale is used. A<1m², B= 1-5m², C >5-25m², D>25-50m², E>50-500m², F>500-5000m². For Ranunculus ololeucos, Carex diandra Counting method: estimation of the occupancy of the growth area per m² from May to June. Each area has to be surveyed once every 3 years. The Floron scale is used. A<1m², B= 1-5m², C >5-25m², D>25-50m², E>50-500m², F>500-5000m². For Mentha pulegium Counting method: estimation of the occupancy of the growth area per m² from July to September. Each area has to be surveyed once every 3 years. The Floron scale is used. A<1m², B= 1-5m², C >5-25m², D>25-50m², E>50-500m², F>500-5000m². For Deschampsia setacea, Halimione pedunculata, Potamogeton compressus Counting method: estimation of the occupancy in the growth area per m² from July to August. Each area has to be surveyed once every 3 years. The Floron scale is used. A<1m², B= 1-5m², C >5-25m², D>25-50m², E>50-500m², F>500-5000m². For Scirpus triqueter Counting method: estimation of the occupancy in the growth area per m² from mid June to mid July. Each area has to be surveyed once every 3 years. The Floron scale is used. A<1m², B= 1-5m², C >5-25m², D>25-50m², E>50-500m², F>500-5000m². For Eriophorum gracile Counting method: estimation of the occupancy of the growth area per m² from May to July. Each area has to be surveyed once every 3 years. The Floron scale is used. A<1m², B= 1-5m², C >5-25m², D>25-50m², E>50-500m², F>500-5000m².

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 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, 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 at https://meetnetten.be/#group-5. This dataset covers the plant occupancy per m² protocol, for which there are 13 target species.

1. Plantae
   rank: kingdom
2. Tracheophyta
   rank: phylum
3. Potamogeton coloratus
   common name: Weegbreefonteinkruid rank: species
4. Ranunculus ololeucos
   common name: Witte waterranonkel rank: species
5. Mentha pulegium
   common name: Polei rank: species
6. Utricularia ochroleuca
   common name: Bleekgeel blaasjeskruid rank: species
7. Wahlenbergia hederacea
   common name: Klimopklokje rank: species
8. Deschampsia setacea
   common name: Moerassmele rank: species
9. Potamogeton acutifolius
   common name: Spits fonteinkruid rank: species
10. Scirpus pungens
    common name: Stekende bies rank: species
11. Halimione pedunculata
    common name: Gesteelde zoutmelde rank: species
12. Potamogeton compressus
    common name: Plat fonteinkruid rank: species
13. Scirpus triqueter
    common name: Driekantige bies rank: species
14. Carex diandra
    common name: Ronde zegge rank: species
15. Eriophorum gracile
    common name: Slank wollegras rank: species

Flanders, Belgium