**3. Distribution**

*Habitats of the World - Biodiversity and Threats*

**2. Diagnosis**

thermomediterranean bioclimate and correspond to the mature phase or climax of the

The Mediterranean Basin, and specifically the eastern region of Andalucia (Spain) and some islands as Sicily (Italy), accumulates a group of environmental conditions which result in the existence of these variety of habitats that have given shelter to paleoendemic species and favored specialization processes [5, 6]. This habitat, which is represented by the communities of arborescent scrub with *Ziziphus*, forms the type of vegetation that can produce the maximum of biomass in relation to the prevailing climatic conditions. These conditions include an arid and warm summer, typical of the Mediterranean climate, with low or no water availability for plants. In addition, the arrangement of this type of vegetation in hemispherical clusters is very impressive from the landscape point of view, and it has elicited

Typical scrub formations of the pre-desert climate are characterized by the presence of thorny, intricate species with leaves of small size and that are often deciduous. These types of vegetation are controlled by climatological factors such as the absence of frost, the water deficit during the dry season (high temperatures and absence of precipitation), mild annual average temperatures, and high solar radiation throughout the year [8]. The cases with greater development correspond to communities characterized by several strata of shrubs, bushes, and herbaceous species, dominated by shrubs up to 3 m high, thorny and impenetrable, which are often aggregated forming islands of vegetation (**Figure 1**). Taxa of tropical-subtropical origin or relicts of past climatic conditions, such as *Z. lotus*, *G. senegalensis*,

They develop below 300 m elevation, in semiarid and frost-free environments, on various types of substrates, although with preference for limestone, occupying depressions, riverbeds, and sporadic water flow zones, where the roots of these

climatophilous and edapho-xero-psammophilous vegetation series [2–4].

various interpretations about the community dynamics [7].

*P. laevigata* subsp. *angustifolia*, etc., dominate them.

*General view of the habitat 5220\* and zoom on Z. lotus and G. senegalensis.*

large shrubs could get water [9, 10].

**12**

**Figure 1.**

This habitat is distributed through the Mediterranean Basin. In the European context, it has been inventoried in 55 Natura 2000 sites from three countries, where there are populations of species that characterize it [2]. In Cyprus, it covers an area larger than 113 ha distributed in 11 natural areas, and worthy of note is the presence of this habitat in Italy [14], which appears very locally (1.56 ha) and exclusively in three areas of Sicily, and in some surrounding smaller islands. On the contrary, in Spain, the habitat is more widely distributed and occupies more than 12,900 ha (**Table 1**). It presents in Andalucia, mainly to the south and east of the province of Almeria [15], and in more or less specific zones of the coast of the provinces of Granada and Malaga [4]. In addition, this habitat occupies the southern part of the Region of Murcia and the Valencian Community, in locations clearly exposed to marine influence and other inland territories (**Figure 2**) [16].



**15**

**Figure 2.**

*Inventoried distribution of the habitat type 5220\*.*

*Intensive Habitat Loss in South Spain: Arborescent Scrubs with* Ziziphus *(5220\*)*

**4. Phytosociological associations related to habitat 5220\***

tions arranged toward localities of marine influence [20].

The plant communities that constitute the habitat 5220\* correspond to different phytosociological associations integrated in the syntaxnomic scheme of the *Quercetea ilicis* Br.-Bl. ex A. & O. Bolòs 1950 class [17–19]. Considering the geographical distribution, the general characteristics of the associations included in the habitat arborescent matorral with *Ziziphus* are listed and detailed below (**Table 2**). In Italy, the *Z. lotus* communities are included within the alliance *Oleo sylvestris-Ceratonion siliquae*. Particularly, the association *Asparago acutifolii-Ziziphetum loti* defines the vegetation with *Z. lotus* that conserves some specimens of thorny scrubs, settled on white organogenic calcarenites, at altitudes between 5 and 75 m above sea level, in a short band of the northwest coast of Sicily. Communities nowadays relegated to disturbed or even semirural environments, near the towns and the edges of the road, are often in contact with some herbaceous or halophytic forma-

Otherwise, the communities of the alliance *Periplocion angustifoliae* are endemic

associations with a particular phytosociological and phytogeographic interest. These communities are distributed in bioclimatic areas between the upper inframediterranean semiarid and the lower thermomediterranean dry thermotypes. *Calicotomo infestae-Rhoetum tripartitae* is an association from Sicily, composed of a xerophilous scrub dominated by *Calicotome infesta* (C.Presl) Guss. and linked to particularly arid habitats on calcareous substrates. Interesting elements of North African origin are found, such as *Rhus tripartita* (Ucria) Grande and *R. pentaphylla* (Jacq.) Desf., quite rarely in Sicily. This peculiar vegetation, now reduced to a few patches almost destroyed and fragmented, is found along the coastal strip of the

*DOI: http://dx.doi.org/10.5772/intechopen.85286*

#### **Table 1.**

*Natura 2000 sites where the habitat type 5220\* is registered.*

*Intensive Habitat Loss in South Spain: Arborescent Scrubs with* Ziziphus *(5220\*) DOI: http://dx.doi.org/10.5772/intechopen.85286*

**Figure 2.** *Inventoried distribution of the habitat type 5220\*.*
