Western basiphilous garrigue
|Red List habitat type||code RLF6.1a|
|Source||European Red List habitat factsheet|
|European Red List of habitats reports|
|European Red List of habitats (Excel table)|
Scrub vegetation dominated by xerophytic chamaephytes, mostly of cushion-shaped, nano-phanerophytes and sometimes tuffed perennial grasses and hemicryptophytes, on shallow or eroded soils derived from rocks with alkaline reaction of the western Mediterranean subregion. Common substrata are limestone (calcium carbonate rich), dolomitic (magnesium carbonate rich) and ultramafic rocks with alkaline reaction. The habitat type F6.1a is, in most cases, seral vegetation stage following degradation of zonal forests distributed from the thermo to meso-mediterranean, seldom to the low supra-mediterranean, semi-arid to sub-humid vegetation belts. In rocky outcrops or crests it may have a permanent character and form the climax vegetation. Also in semi-arid regions, such as those in the Murcia-Almerian province, it may stand as permanent vegetation in large areas.
The habitat is frequently dominated by shrubs of the families Labiatae and Fabaceae of neomediterranean character. It comprises a broad diversity of plant communities, especially in Spain, and includes many local endemic taxa, thus having a high conservation value. This vegetation has historically expanded its area due to soil erosion after the destruction of woodlands for agriculture and cattle grazing. It may also be promoted by wildfires, as most plants are R-strategist seeders and fire-prone. The biogeographic and bioclimatic variability allows the recognition of three subgroups (vegetation orders): Rosmarinetalia (dry to subhumid central and west Iberian limestone), Antyllidetalia terniflorae (semi-arid limestone and marl Murcia-Almerian province) and Convolvuletalia boissieri (dolomite and ultramafic), containing in total thirteen alliances.
As basiphilous garrigues have enormous syntaxonomic and floristic diversity in the western Mediterranean, some degree of interpretation is needed. We follow the concept of Mucina et al. (2014) with several modifications. The core concept is that of chamaephyte- and nano- phanerophyte-dominated scrub on eroded or thin soils in substrata with alkaline reaction, either derived from limestone, dolomitic (rich in magnesium carbonate) or sometimes ultramafic rock, in thermo-mediterranean and meso-mediterranean belts. The vegetation corresponds to a large part of the class Rosmarinetea officinalis (in the sense of Rivas-Martínez et al., 1991, = Ononido-Rosmarinetea in Mucina et al.) and mostly to the widespread dry to sub-humid order Rosmarinetalia. Also the semi-arid limestone communities of the Murcia-Almerian province (order Anthyllidetalia terniflorae) are included. Gypsum communities (order Gipsophylletalia) are excluded (included in F6.7), but magnesium-prone ones are included (order Convolvuletalia boissieri). The equivalent habitats in west european calcareous mountains, mostly in supra and oro-mediterranean thermotypes, sometimes in sub-mediterranean temperate bioclimate are excluded and systematized in F6.6, F6.7 and F7.4. By the same reasoning all hedgehog heath (order Erinacetalia anthylis) is excluded and belongs to F7.4. The following syntaxa, in many cases ascribed to Rosmarinetea are thus excluded from F6.1a: Erysimo-Jurinetalia bocconei (F7.4b), Festuco-Ononidetalia striatae (F74.a). Also, not following Mucina et al., mountain garrigues of the following alliances are excluded: Polygalo-Genistion corsicae, Helianthemo-Aphyllantion monspeliensis (F6.6), Alyssion bertolonii (F7.4a), Artemisio albae-Saturejion montanae (F7.4a), Lavandulo latifoliae-Genistion (Echinospartion) boissieri (F6.6), Siderito incanae-Salvio lavandulifoliae (F6.6). However Cisto eriocephali-Ericion multiflorae is included to stand for an Italo- Thyrrenean irradiation of the east-mediterranean Cisto-Micromerietea class or otherwise considered in Rosmarinetea (West Mediterranean). Garrigues in limestone sea-cliffs (order Helichrysetalia italici) are excluded and classifiable in either F7.1-2 (west Mediterranean coastal garrigues) or B3.1-3b (Mediterranean and Black Sea rocky shores).
Indicators of good quality:
Apart from the primary ecological niches of the habitat (crests and rocky outcrops), it’s presence is s dependent on disturbances of low to moderate degree; otherwise, it is expected to be substituded along the succession process by forest communities. Although such processes are slow or even ‘locked’ by persistence of disturbance or feeble water capacity, the whole mosaic of garrigues and other habitats (grasslands, forests) in dry sub-humid types with shallow soils should be balanced by active management (burning or traditional agriculture and grazing). At its permanent positions on rock crests no management is required for the conservation of the habitat. Species rich, “saturated” variations of the habitat need the emphasis to be given on conservation, while the species-poor pioneer stages are of lower conservation value but potentially these evolve into more species rich communities.. Another indicator of the habitat’s good quality is the presence of the majority of its local characteristic species.
Synthesis of Red List assessment
|Red List Category||Red List Criteria|
|Red List Category||Red List Criteria|
Confidence in the assessment
Pressures and threats
- Agricultural intensification
- Sylviculture, forestry
- Artificial planting on open ground (non-native trees)
- Urbanisation, residential and commercial development
- Discontinuous urbanisation
- Natural System modifications
- Lack of fires
- Natural biotic and abiotic processes (without catastrophes)
- Species composition change (succession)
Habitat restoration potential
Trends in extent
Average current trend in quantity
Trends in quality
Average current trend in quality
Conservation and management needs
When designing management meaures in the context of local and regional policies, the local and regional variants of the habitat type (F6.1b) with the possible peculiarities in species and endemic/rare/threatened species composition should be taken in account.. The most effective way of implementing different conservation measures depending on the conservation value of the different sub-types of the same habitat type is to use their species composition for different legal conservation status and actions.
Micro-reserves or other designation regimes sites network could safeguard, , even in agricultural territories, the preservation of all the constituent flora species and mature status of the habitat. The short fallow periods implie that habitats are always kept in early succession stages characterized by a low number of species (pioneer species). In conservation oriented agricultural land, i.e. managed to include also conservation objectives, the maintenance of a proportion of land with longer fallow period (thus allowing succession and species saturation of the habitat) is suggested.
List of conservation and management needs
- Measures related to agriculture and open habitats
- Other agriculture-related measures
- Measures related to spatial planning
- Establish protected areas/sites
- Establishing wilderness areas/allowing succession
- Legal protection of habitats and species
Geographic occurrence and trends
|EU28||Present or presence uncertain||Current area of habitat (Km2)||Recent trend in quantity (last 50 years)||Recent trend in quality (last 50 years)|
|EU28 +||Present or presence uncertain||Current area of habitat (Km2)||Recent trend in quantity (last 50 years)||Recent trend in quality (last 50 years)|
Extent of Occurrence, Area of Occupancy and habitat area
|Extent of Occurrence (EOO) (Km2)||Area of Occupancy (AOO)||Current estimated Total Area||Comment|
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).