Mediterranean and Macaronesian coastal dune grassland (grey dune)

These stable coastal dunes of the Mediterranean are dominated by herbs, graminoids and chamephytes, with a broad variety of plant communities: a) fixed dunes of the western and central Mediterranean and North Africa, with Crucianella maritima (a steno Mediterranean species) and Pancratium maritimum; b) coastal stabilised dune grassland communities with medium to fine calciumcontaining sand, growing approximately 200 m from the sea on dunes of about 0.15-10 m; c) associations with many small annuals and often abundant ephemeral spring bloom of deep sands in dry interdunal depressions of the coasts: d) dune formations of pseudo-steppe with grasses and annuals of the Thero-Brachypodietea class; e) meso- and thermo-Mediterranean xerophile, mostly open, short-grass perennial grasslands rich in therophytes, as well as therophyte communities of oligotrophic soils on base-rich, often calcareous substrates. All of these components are established generally landwards of the white dunes. The term "grey dunes" originates from the color of the substratum which comes from the increased proportion of humus and silt in the sand. Here, the amount of windblown sand is much reduced, compared to the white dunes, and also salt spray and erosive processes are highly reduced, with higher plant cover. The number of species in general is higher than in shifting dunes. These communities may be followed in succession by evergreen sclerophyllous coastal scrubs and in some cases by Quercus ilex woodlands, but may form relatively stable grassland in more extreme sites, less suitable for shrubs.

Human pressures reduce coastal landscape heterogeneity and biodiversity and converge to a striking simplification of the natural zonation on highly urbanized coasts. The impoverishment of soils in highly disturbed areas not only reduces the number of typical native species, but also promotes the colonization of alien and ruderal species. Touristic development and recreational activities (trampling, infrastructures) are the most severe threats for dune habitats, together with land clearance for the expansion of cultivated lands, sand extraction and changes due to in sand enrichment. In fact, large parts of the Mediterranean grey dunes are currently influenced by touristic and recreational activities, or have changed to urbanized areas, arable lands or woody plantations.

Indicators of good quality:

The following characteristics may be considered as indicators of good quality, but these indicators differ in different regions:
- High species richness
- Presence of rare and/or threatened species
- Diversity within the type within an area and over the whole range
- High cover of open soil
- Low cover of encroaching tall grasses, tall herbs and shrubs
- No cover of alien species
- No or few indications of disturbance

Synthesis of Red List assessment

Confidence in the assessment

Pressures and threats