Thermomediterranean scrub

Low to medium-sized scrub in the arid and semiarid South Mediterranean areas in southeast Spain, south Sicily, the southern Aegean islands, and south Cyprus, further in lowland Mediterranean North Africa and the Near East. They often form dense or sometimes more widely spaced, frequently spiny shrub patches. Open ground in between supports numerous xerophilous herbaceous plants and subshrubs. Sclerophyllous species are dominant (e.g., Pistacia lentiscus, Periploca angustifolia) as well as deciduous shrubs (e.g., Zizyphus lotus) and dwarf palms (Chamaerops humilis). Depending on the region and aspect of the vegetation, formations have been referred to as retamal (dominated by broom shrubs; mainly covered by habitat F3.1c), palmetto (dwarf palm), tomillar (dominated by needle-leaved or otherwise microphyllous Labiatae) or garrigue (dominated by Cistus, Pistacia and other shrubs). Most types of thermo-Mediterranean arid scrub are 2-3 metres tall, and they occur abundantly along the arid to semiarid North African Mediterranean coasts, being represented only in a few areas in Europe. Woodlands of Tetraclinis and Ziziphus reach 5-6 m.

Thermo-Mediterranean arid scrub occurs on a wide variety of bedrock and exclusively on dry soils. Rocky calcareous or dolomitic lithosols, sandy soils or eroded marly, gypsum and argillite sites are most common. On marly and argillaceous soils it is often affected by soil flow-off. The scrub is frequently wind-exposed, sometimes moderately halophytic if on sea cliff tops. Some subtypes of thermo-Mediterranean scrub may be replaced by woodland in the course of succession but scrub of the most arid and most exposed sites tends to be stable under current conditions and is considered natural or seminatural vegetation, particularly in SE Spain (Murciano-Almeriense province). Some stands are hardly accessible and thus only little affected by human influence. Many of the stands are however browsed by domestic animals (goats), sometimes severely.

Due to the extremely variable species composition and wide geographical range, thermo-Mediterranean scrub forms numerous plant associations and alliances and is part of several phytosociological classes. Dominant plants are Periploca angustifolia, Tetraclinis articulatus, Gymnosporia europaea and Zizyphus lotus, but in all the cases the shrubland is extremely dense, inextricable and spiny, being practically impenetrable. It produces abundant organic matter which favors the soil formation, being a valuable habitat type for soil protection and against erosion. Among the widespread plant communities occurring in this habitat are some of those dominated by Pistacia lentiscus (throughout the South Mediterranean), and most stands of Euphorbia dendroides (from the Balearic Islands to the East Mediterranean) and Periploca angustifolia (from Spain and Northwest Africa to the South Aegean). Many other habitat-specific shrubs, dominant or not, are restricted to single islands or island groups, such as Euphorbia melitensis dwarf shrublands on Malta, Cytisus aeolicus in Sicily, Genista ephedroides in Sardinia and Genista majorica on the Balearic island of Mallorca.

Indicators of good quality:

• Absence of greenhouse farming
• No construction or building works, garbage dumping, solar panels, traffic, or other serious habitat impact.
• No evidence of overgrazing
• Absence of alien species such as Oxalis pes-caprae (the latter recognizable above ground only in early spring)

Synthesis of Red List assessment

Confidence in the assessment

Pressures and threats