Ecological and phytosociological comparison between Quercus ilex L. subsp. ilex of southern Italy and Q. rotundifolia Lam. of southern Iberian Peninsula

As part of a collaboration between the University of Évora (Portugal), Jaén (Spain) and Reggio Calabria (Italy), are studied and compared the communities of Quercus rotundifolia Lam. (= Quercus ilex L. subsp. ballota (Desf.) Samp.) of the southern Iberian Peninsula and those in Quercus ilex L. subsp. ilex in southern Italy. On the taxonomy of Quercus rotundifolia there is no agreement among the various authors, with some who consider it as a subspecies of Quercus ilex, while others remain as autonomous species. The research undertaken by us allow you to highlight important differences between Quercus ilex and Quercus rotundifolia, not only from the morphological point of view, but also chorological, bioclimatic and vegetation. Morphologically you can appreciate the differences in the leaf, the fruit of the tree and bearing between the two taxa: all aspects that we are studying and that will be reflected in appropriate future work. Regarding chorology Quercus ilex subsp. ilex, has its optimum in the Italian peninsula and in the islands of the Central Mediterranean, arriving in its Western to the territory of the community of Valencia, Catalonia (Spain) and Provence (France). Proceeding eastward reduce its presence in Greece, including Crete (Barbero & Quézel, 1976), where it forms located forests, becoming more sporadic in the eastern and southern coast of the Black Sea (Czeczott, 1939; Quézel et al., 1980). There are no reports of this taxon in the south of the Iberian Peninsula or North Africa. Quercus rotundifolia instead occupies most of the Iberian peninsula, except the Euro-Siberian northern part, its presence is marginal in Portugal (Amaral Franco, 1990, Quézel & Médail, 2003), and is very common in the Mediterranean areas of North Africa. By some authors (Lebreton et al., 2001) North African populations are distinct, based on biochemical and morphological criteria, in subsp. maghrebiana Lebreton, Barbero et Quézel. According to Rafii et al. (1993), and Michaud et al. (1995), the population of north-west Spain, Catalonia, Languedoc and Provence are intermediate morphotypes result of widespread introgression events between the species with western distribution and those eastern distribution: they can be found here along with Q. rotundifolia (Quézel & Médail, 2003). Quercus ilex subsp. ilex in southern Italy is widespread from the hills to the submontane belt, from 50 to 1100 m, in areas with Mediterranean bioclimate (penetrating locally in temperate one) from thermo to supra and from sub-humid to humid, with optimum in the Meso-Mediterranean sub humid bioclimate: form climatophilous or edaphophilous woods belonging to the Mediterranean region and, more narrowly, to the Euro-Siberian. Quercus rotundifolia is a plant present in Mediterranean environments, is spread from thermo to supramediterranean thermotipe with optimum dry ombrotype, without reaching the semi-arid. Can penetrate punctually in the sub-humid and humid, as long as the soil is rocky and has poor water retention capacity, forming edaphoxerophilous communities may form forests climatophilous only in dry-subumid environments. There are no significant edaphic differences between Q. ilex and Q. rotundifolia, as both are indifferent to the substrates. Q. rotundifolia woods can reach 1500-1800 m in the Iberian Peninsula. Associations with Quercus rotundifolia in southern Iberian Peninsula, according to Rivas-Martínez et al. (2001, 2002), to which reference is made for the authors and syntaxonomic sorting, are Asparago acutifolii-Quercetum rotundifoliae. Adenocarpo decorticantis-Quercetum rotundifoliae. Berberido hispanicae-Quercetum rotundifoliae. Lonicero implexae-Quercetum rotundifoliae. Paeonio coriaceae-Quercetum rotundifoliae. Pyro bourgaeanae-Quercetum rotundifoliae. Myrto communis-Quercetum rotundifoliae. Rhamno oleoidis-Quercetum rotundifoliae. In southern Italy and Sicily (excluding Sardinia) according to Biondi et al. (2003) and Brullo et al. (2008), are known the following associations: Erico arboreae-Quercetum ilicis, Pistacio lentisci-Quercetum ilicis, Cyclamino hederifolii-Quercetum ilicis, Rhamno alaterni-Quercetum ilicis, Teucrio siculi-Quercetum ilicis, Ostryo carpinifoliae-Quercetum ilicis Cephalanthero longifoliae-Quercetum ilicis, Festuco exaltatae-Quercetum ilicis, Quercetum frainetto-ilicis, Melitto albidae-Quercetum ilicis, Doronico orientalis-Quercetum ilicis, Aceri campestris-Quercetum ilicis, Sorbo graecae-Quercetum ilicis, Hedero helicis-Quercetum ilicis.