Relict mire of Mediterranean mountains

Oligo- to mesotrophic mires of the montane and subalpine belts of Mediterranean mountains of the High Atlas (Morocco), Sierra Nevada and Corse, and of high mountains (above 1900 m altitude) of the Western Balkan peninsula. These mires occur on the edges of glacial lakes and around mountain streams, forming waterlogged ‘blankets’ in relatively flat areas with impermeable soils, where a peat layer has developed on siliceous bedrocks. The type is differentiated from mires and grasslands with a similar physiognomy in the Alps, Pyrenees and rest of the Balkan by the presence and dominance of narrow-endemic relict species, and by the lower frequency of Sphagnum species. The sites of this habitat in the South-European mountains are characterised by relative cold and humid conditions, creating a distinct green habitat in a dry landscape. Water supply and temperature vary relatively little during the year, compared to surrounding habitats. In the high mountains of the Balkan this habitat is covered by snow most of the year.

The mires are bordered by streams, springs and lakes on the lower edges, and by moist grasslands with Nardus stricta (E3.2b) on the drier edges. The habitat is dominated by Carex nigra ssp. intricata in the Sierra Nevada and Corse, and by Carex nigra var. macedonica in the Balkan. In Spain also Festuca frigida may dominate, while in Corse along streams Trichophorum cespitosum may be dominant. Common species in both Mediterranean regions are Carex echinata, Carex nevadensis, Agrostis canina and Viola palustris. Different characteristic endemic species  are found in the different regions. For several genera, vicariant endemic species are found in the different mountain regions. Such species are considered tertiary relicts. Examples in these mires are Pinguicula nevadensis, Pinguicula corsica and Pinguicula balcanica, and also Narthecium reverchonii (Corse) and Narthecium scardicum (Balkan). Some of the characteristic species also grow outside the mires, like Pinguicula corsica and Narthecium reverchonii along waterfalls on wet rocks. Together with the adjacent Nardus grasslands of E3.2b, these conspicuous habitats are called Pozzines in Corse and Borreguiles in the Sierra Nevada.

Indicators of good quality:

In wet conditions these grasslands are relatively stable. Desiccation causes a succession towards Nardus grasslands of E3.2b. Abandonment leads to the development of tall herb vegetation. The type may expand slowly by vegetation succession in open water. Indicators of good quality are:

• presence of endemic species
• high vegetation cover
• low cover of (encroaching) tall herbs and shrubs
• situated in a gradient from water to drier grassland

Synthesis of Red List assessment

Confidence in the assessment

Pressures and threats