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h1. H2130 - Fixed coastal dunes with herbaceous vegetation ('grey dunes')


h1. General
{section}{column:width=80%}
|| General characteristics || ||
| Common name | Fixed coastal dunes with herbaceous vegetation ('grey dunes')|
| Region | Europe |
| Water system | coastal waters |
| Nature parameter | Habitat types |
| HR nr | H2130 |
| Fact sheet by | K.E. van de Wolfshaar |{column}{column:width=20%}
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h1. Description habitat


h3. General occurrence

This priority habitat type includes fixed dunes, stabilised and colonised by more or less closed perennial grasslands and abundant carpets of lichens and mosses, from the Atlantic coasts (and the English Channel) between the Straits of Gibraltar and Cap Blanc Nez, and the shores of the North Sea and the Baltic. These so-called "grey dune" are located more land inward than the "white dunes" covered with European Marram grass (habitat type [H2120|HBTDB:H2120 - Shifting dunes along the shoreline with Ammophila arenaria ('white dunes')]). This habitat type includes various species of dune grasslands of the class dry and calcareous dune grasslands (_Polygalo-Koelerion_), Syntrichia association (_Tortulo-Koelerion_), Common bent association (_Plantagini-Festucion_), Dune- grey hair-grass association (_Corynephorion canescentis_) and  species-rich Nardus grasslands (_Nardo-Galion saxatilis_). In The Netherlands, this habitat type occurs in all coastal dunes, from Schiermonnikoog to the Zwin. Some of these communities are very special, as they only occur in The Netherlands and include a large number of rare species. This specifically concerns the grassy dunes with dandelions, communities of the so-called seavillage landscape and communities of lime-poor old dunes. Because of air pollution, reduction of dynamics and a sharp decline in rabbit population, this habitat type is threatened with extinction on many locations, as grasses or brushwood becomes the dominating vegetation. The landscape of seavillages is well-developed in the calcareous Dutch dunes near old fishing villages such as Scheveningen, Katdijk, Noordwijk, Wijk aan Zee and Egmond. Grassy dunes with dandelions mostly occur on calcareous dunes south of Bergen. Old dunes are mostly found on Goeree and Schouwen  [#1].


h3. Environmental boundary conditions

Small scale human influences are characteristic for a sea village landscape, such as treading and grazing, and in the past also the fixing and drying of nets, bleaching of linen and growing potatoes. This kind of landuse has led to local sand-drifts and a larger variety of food, resulting in a strong variety of habitats within a short distance. Noticeable species of this landscape type are Sand catchfly (_Silene conica_), Nottingham catchfly (_Silene nutans_), Spanish catchfly (_Silene otites_), Field sagewort (_Artemisia campestris_ subsp. _maritima_), Spring millet Grass (_Milium vernale_), Pyramidal orchid (_Anacamptis pyramidalis_) and Yarrow broomrape) (_Orobanche purpurea_). Grassy dunes with dandelions are probably the most characteristic for grey dunes. These grasslands need a calcareous habitat. Grasslands are conserved by slight sand-drifts, rabbit grazing and grazing by cattle or horses.  Besides a number of specific dandelions, the following characteristic species occur: Teesdale violet (_Viola rupestris_) and Star gentian (_Gentiana cruciata_). In dune areas with stable rabbit populations, the grassy dunes with dandelions are mostly well preserved. However, if the rabbit populations diminish, there is a threat of becoming overgrown with grasses such as Wood small-reed (_Calamagrostis epigejos_) or  Creeping willow (_Salix repens_). Old dunes can be found on locations near old dunes that used to be grazed, the so-called common land. The present grasslands have best developed on places where the old dunes have kept their original, slightly fluctuating relief. Here, endangered species such as Autumn lady's-tresses (_Spiranthes spiralis_) and Field gentian (_Gentianella campestris_) occur. 

h3. Control and growth opportunities

Grazing and treading are important factors for maintaining this habitat type, as it prevents grasses and brushwood to become the dominating vegetation.  Deterioration of this type is mainly caused by air pollution, reducing of dynamics and a sharp decline in rabbit population [#1].

h1. Dose-effect relations

These dose-effect relations have been based on habitat factors of occurring plant communities. The habitat type itself is a landscape characteristic and therefore it is difficult to define relations. 
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h4. Flowchart
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h5. General dose-effect relations
{section}{column:width=50%}
{chart:type=bar|title=Soil type|xlabel=soil type|yLabel=HAI|dataDisplay=true|dataOrientation=vertical|legend=false}
||soil type||HAI ||
|sand|1|
|loamy sand|1|
|loam|1|
|other|0|
{chart}
Reference: [#1]{column}{column:width=50%}
|| district || || || || occurrence class || || ||
| | Dune- Grey Hair-grass | Common bent | Syntrichia | Dune grasslands | Species-rich Nardus grasslands || Habitat type |
| Wadden | V | V | V | V | V | V |
| Renodunaal | W | V | V | V | V | V |
| Gelders | A | W | A | A | A | W |
| Kempens | A | W | A | A | A | W |
| Vlaams | A | W | A | A | A | W |
Legend: V: much; W: few; A: not present
Reference: [#2]{column}{section}

{section}
{column:width=50%}
||Salinity||HAI||
|very fresh|1|
|other|0|
Reference: [#1]
{column}
{column:width=50%}
||Humidity soil||HAI||
|humid|1|
|dry|1|
|other|0|
Reference: [#1]
{column}{section}


h1. Uncertainty and validation

(!) These dose-effect relations have not been validated. 

h1. Applicability

These dose-effect relations have been based on the habitat factors of the plant communities included in this habitat type. These two characteristics have not been included in the dose-effect relations because of the variety in occurrence of the plant communities, depending on the intensity of grazing and the amount of lime the soil contains.


h1. Example project

At present, there is no example of a project available. 

h1. References

1 {anchor:1} [http://www.minlnv.nl/natura2000]
2 {anchor:2} Weeda, E.J., J.H.J. Schaminee, L. van Duuren (2003). Atlas van Plantengemeenschappen in Nederland. Deel3 Kust en binnenlandse pioniermilieus. KNNV Uitgeverij.