Western Mediterranean

The Mediterranean climate zone in the Mediterranean Basin region covers an area of some 2,300,000 km2 around the Mediterranean Sea. There are around 19,000 species in this region, 21% of them endemic.

The climate is characterised by very dry summers due to the influence of the powerful Azores anti-cyclone, and by damp winters due to the passing of cyclones. A markedly continental nature results in summer storms and intense cold in winter, with frequent freezing temperatures that may restrict plant development.

Generally speaking, the vegetation of the Mediterranean Basin has been subject to intense changes caused by human activity over thousands of years. Many Mediterranean forests have become smaller or have been replaced by shrub communities known variously as “maquia, “maleza” or “matorral”.

The vegetation of the Mediterranean Basin is extensively represented in the Botanical Garden, subdivided into three zones: the Eastern Mediterranean, the Western Mediterranean and North Africa.

· THE FORESTS OF THE WESTERN MEDITERRANEAN ·

Montane holm oak forest Forests of evergreen trees growing on calcareous soil, predominantly holm oak (Quercus ilex), accompanied by such species as Scots pine (Pinus sylvestris), sweet chestnut (Castanea sativa) and laurel (Laurus nobilis). Herbaceous plants and shrubs such as Fragaria vesca, Pteridium aquilinum, Helleborus foetidus and Prunus spinosa are species that appear frequently in oak woods.

Coastal holm oak forest Calcareous evergreen forests dominated by holm oak (Quercus ilex), and differentiated from mountain holm oak woods by the presence of such tall shrub species as the strawberry tree (Arbutus unedo), Laurustinus (Viburnum tinus), the heath tree (Erica arborea) and such low shrubs as butcher’s broom (Ruscus aculeatus). Creeping plants are a singular feature of such communities, the predominant species being roses (Rosa sempervirens), ivy (Hedera helix), honeysuckle (Lonicera implexa) and sarsaparilla (Smilax aspera).

Cork oak forest Forests growing on flinty soil, formed by evergreen trees, predominantly cork oak (Quercus suber), accompanied by maritime pine (Pinus pinaster). Cork oak forests are less dense, and are rich in light-tolerant shrubs. The composition of this undergrowth is  similar to that of the coastal holm oak forest.

Acidophilous oak forest Deciduous forests growing on well-drained acid soils that are poor in nutrients. This is an Atlantic-type community, in which the predominant species are the sessile oak (Quercus petraea) and common oak (Quercus robur), accompanied by tall shrubs such as hazel, hawthorn and sloe.

Basophilous oak forest Deciduous forests growing on fertile, well-drained alkaline soil. The predominant species are oaks such as the Portuguese oak (Quercus faginea), the downy oak (Quercus humilis) and other deciduous trees such as maple(genus Acer) and rowan (genus Sorbus) often accompanied by large formations of box (Buxus sempervirens).

River forest Forest communities that inhabit damp places. The predominant species are central European deciduous trees. Formations in which European alder (Alnus glutinosa) predominate are known as “alisales” and are accompanied by European ash (Fraxinus excelsior) and shrubs such as elderberry (Sambucus nigra) and hazel. Formations in which white poplar (Populus alba) predominate are known as “alamedas” and are accompanied by narrow-leaved ash (Fraxinus angustifolia) and elms (Ulmus minor), and by such shrubs as hawthorn (Crataegus monogyna) and blackberry (Rubus ulmifolius).

Beech forest Mid-European Atlantic forest formed by a very dense arboreal stratum, shady in summer, and a herbaceous stratum which flourishes in autumn. The arboreal stratum is dominated by European beech (Fagus sylvatica), along with other shade-tolerant trees such as the Swiss pine (Abies alba) and the English holly (Ilex aquifolium). In the shrub stratum we find box (Buxus sempervirens) and hazel (Corylus avellana).

WESTERN MEDITERRANEAN SHRUB FORMATIONS

Basophilous scrub These dense, very open formations on limestone soil, growing up to 3 m in height, harbour such shrub-like trees as the wild olive (Olea europaea var. sylvestris) and the carob (Ceratonia siliqua). The most common shrubs here include, particularly, the evergreen pistache (Pistacia lentiscus), the Mediterranean heath (Erica multiflora) and various lavender species (Lavandula dentata, L. angustifolia and L. latifolia). Also found here is the fan palm (Chamaerops humilis), one of just two autochthonous European palms.

Valencian rock crevice community Limestone rock formation containing a representation of the most common species in Valencia, as well as endemic species from the Iberian, Pre-Betico and Alicantine mountain systems.

Balearic Island rock crevice community Calcareous rock formation containing a representation of the most  frequently found plants and endemic species from the coast, scrub, oak forests and high mountains of the Balearic Islands. The predominant species in coastal areas are Astragalus balearicus and Launaea cervicornis, whilst holm oak predominates in the scrub and low woody species from the Lamiaceae and Leguminosae families, as well as many geophytes.

Catalan Pre-Pyrenean rock crevice community Catalan rock formation, mainly calcareous, with a section of siliceous rock. The calcareous terrain contains the main endemic and other species found in the mountains of central and southern Catalonia and the Pre-Pyrenees. The siliceous soil features species from the northern mountains and the Eastern Pyrenees.

Andalusian rock crevice community  Under construction »  Calcareous rock formation featuring a large, representative selection of many endemic species from the mountains in the south of the Iberian Peninsula. Most interesting amongst the shrub species are those that take the form of a pin cushion. Many of these species are also found in the African mountains or surrounding area.