Orophilous aspects of relictual vegetation of the class Rhamno-Prunetea localizated on the Madonie Mountains (NW Sicily).

Abstract

The deciduos shrubby mantle coenoses referred to the class Rhamno catharticae-Prunetea spinosae are secondary communities - sometimes permanent - localized in the climactical dominion of the forests of Querco-Fagetea and Quercetea ilicis or the riparian woodlands of Salici-Populetea nigrae. These communities are widespread from the Eurosiberian to the Mediterranean region, and are linked to rich nutrient humic soils, rocky slopes and screes (1). In Italy, the class Rhamno-Prunetea is represented by the alliances Cytision sessilifolii, Berberidion vulgaris, Pruno-Rubion ulmifolii and Salici-Viburnion opali, the latter showing hygrophilous character (2). As concerns the mountain and submountain shrubby communities of southern-Italy and Sicily - excluding the orophilous vegetation of the class Pino-Juniperetea - these have been included so far in the alliance Pruno-Rubion ulmifolii. In fact, the coenoses referred to the others alliances become gradually more scattered on the central-Apenninic reliefs, where even the Berberidion was known up to Abruzzo mountains of Gran Sasso, Velino, Sirente and Maiella (3). In this paper is reported the first record of aspects of primary vegetation of the alliance Berberidion vulgaris in northern Sicily, restricted in a limited area of high Madonie mountains. These are relictual fragments localized along the nothern slopes of several reliefs, near the screes, detritic cones particularly steep, and are dominated by mesophilous entities of the order Prunetalia spinosae and class Rhamno-Prunetea (Lonicera xylosteum, Rhamnus catharticus, Rubus canescens, Euonymus europaeum, etc.), associated with other species of the alliance Berberidion (Ribes uva-crispa, Rosa sicula), other endemic taxa are present (Prunus mahaleb subsp. cupaniana, Berberis aetnensis and Sorbus aria subsp. cretica) regarded as a geovicariants of the character-species of the latter alliance (respectively, Prunus mahaleb subsp. mahaleb, Berberis vulgaris and Sorbus aria subsp. aria). The presence on the Madonie Mts. of other elements of the Berberidion - i. e. Cotoneaster nebrodensis, Rosa montana, Rhamnus saxatilis subsp. infectorius and Amelanchier ovalis subsp. embergeri (vicariant of A. ovalis subsp. ovalis) - must be considered as a further confirmation of the residual character of the sicilian population of this sintaxon, isolated at the extreme south of its distribution area, where probably it would be referred to a new endemic punctiform suballiance. BIBLIOGRAPHY 1) Rivas-Martinez S., Diaz T. E., Fernandez-Gonzalez F., Izco J., Lousa M., Penas A., 2002. Vascular plant communities of Spain and Portugal. Addenda to the syntaxonomical checklist of 2001. Itin. Geobot., 15 (1): 5-432, 15 (2): 433-922. 2) Poldini L., Vidali M., Biondi E., Blasi C., 2002. La classe Rhamno-Prunetea in Italia. Fitosoc. 39(1) suppl. 2: 145-162. 3) Cutini M., Stanisci A., Pirone G., 2002. L'alleanza Berberidion vulgaris in Appennino centrale (Italia Centrale). Fitosoc. 39(2): 31-50.