Dry Grasslands of Hippocrepido Glaucae-Stipion Austroitalicae in the Pollino Massif (Calabria, Italy)
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Acta Bot. Croat. 75 (1), 89–98, 2016 CODEN: ABCRA 25 DOI: 10.1515/botcro-2016-0013 ISSN 0365-0588 eISSN 1847-8476 Dry grasslands of Hippocrepido glaucae-Stipion austroitalicae in the Pollino Massif (Calabria, Italy) Massimo Terzi1*, Franceso S. D’Amico2 1 Institute of Bioscience and Bioresource – CNR, Via Amendola 165, Bari, Italy 2 Dept. of Biology, Botanical Garden Museum, University of Bari, Via Orabona 4, Italy Abstract – Rocky pastures dominated by Stipa austroitalica in the south-east of Italy were classifi ed within an endemic alliance, Hippocrepido glaucae-Stipion austroitalicae, originally assigned to a Balkan order (Scorzoneretalia villosae). Actually, the distribution area of S. austroitalica extends further westwards and large patches are found on the south-east side of the Pollino Massif. This study aims to describe and charac- terise the plant communities dominated by S. austroitalica in this area and analyse their fl oristic and choro- logical relationships with other associations of Hippocrepido-Stipion. Moreover, their syntaxonomy is dis- cussed in the context of the Italian and south European dry grasslands biogeography. The grasslands were studied on the basis of 19 phytosociological relevés. A larger data set, including 185 relevés with S. austroi- talica, was used to visualise the relationships among the associations through nonmetric multi-dimensional scaling ordination. The results allowed the description of a new association, Bupleuro gussonei-Stipetum aus- troitalicae, classifi ed within Hippocrepido-Stipion. As a consequence, the alliance synrange was extended up to the Pollino Massif. The Hip pocrepido-Stipion, together with Cytiso spinescentis-Bromion erecti, was ar- ranged in Euphorbietalia myrsinitidis, an endemic order of the Italian peninsula. The proposed scheme up- grades the syntaxonomy and nomenclature of the dry grasslands vegetation of central and southern Italy. Keywords: calcareous grasslands, Euphorbietalia myrsinitidis, Pollino National Park, Scorzoneretalia villo- sae, Stipa austroitalica, syntaxonomy. Abbreviation: art. – article of the 3rd edition of the International Code of Phytosociological Nomenclature Introduction north-eastern Mediterranean and south-eastern European distribution, the alliance was originally classifi ed within a The alliance Hippocrepido glaucae-Stipion austroitali- Balkan order, Scorzonero villosae-Chrysopogonetalia gryl- cae Forte et Terzi 2005 was originally conceived to describe li Horvatić et Horvat in Horvatić 1963 nom. illeg. – whose the Mediterranean steppe-grasslands of two of the largest correct name is Scorzoneretalia villosae Kovacević 1959 karst areas in the south-east of Italy, Murge hill and Garga- (cf. Terzi in press) – of which it would constitute the south- no promontory, and a few other sites in the Molise Region western outpost (Forte et al. 2005). Actually, the syntaxo- (Fanelli et al. 2001, Forte et al. 2005). The grasslands are nomic position of Hippocrepido-Stipion raised one more characterised by a high fl oristic richness, with a remarkable time the question on the relationship between grassland phytogeographical value. The dominant species, Stipa aus- vegetation of the Italian Peninsula and the western Balkans, troitalica Martinovský, is an endemic species of the south after it has been debated for nearly 40 years (Lakušić 1969, of Italy and is considered a priority species for European biodiversity conservation strategies (Annex II of Directive Horvat et al. 1974, Bonin 1978, Royer 1991, Biondi et al. 92/43/EEC). As a consequence, plant communities of Hip- 1995, Fanelli et al. 2001, Terzi et al. 2010, Biondi and pocrepido-Stipion are worthy of the highest safeguarding Galdenzi 2012, Terzi and Di Pietro 2013, Di Pietro and Wa- and attention (Paura et al. 2014). gensommer 2014, Biondi et al. 2014a). Besides its importance for biodiversity conservation, Although the largest phytocoenoses with S. austroitali- Hippocrepido-Stipion is also of particular concern for the ca can be found along the southern part of the Italian Adri- biogeography of Mediterranean vegetation in the European atic border, the species was recorded in many other sites in context. In fact, due to the presence of many taxa with a the south of Italy, with large patches also on the south-east- * Corresponding author, e-mail: [email protected] ACTA BOT. CROAT. 75 (1), 2016 89 TERZI M., D’AMICO F. S. ern side of the Pollino Mountain range, in Calabria Region the most important river of the area. The geological struc- (Moraldo 1986, Brandmayr et al. 2002). It is interesting to ture of the area is quite complex with Mesozoic calcareous- observe that Bonin (1978) – who fi rst extended the distribu- dolomite reliefs, quaternary soils of the river basin, sedi- tion area of Scorzoneretalia villosae up to southern Italy – ments of Miocene and Pliocene-Pleistocene deposits, based his hypothesis on a phytosociological study on the outcrops of Palaeozoic rocks (sericite schists, phyllites, cal- grasslands of the Pollino Massif. Bonin’s relevés (Bonin careous schists) (Giannini et al. 1963). The Stipa austroi- 1978) were carried out from nearly 800 m above sea level talica communities develop mainly on limestone, often out- (asl) upward and, even if they include some records of Sti- cropping, in an area roughly between 300–800 m asl. pa mediterranea Trin. et Rupr., it seems improbable that The bioclimate of the study area, deduced from the ther- they could be referred to S. austroitalica, whose grasslands mo-pluviometric data of the meteorological station of Cas- develop mainly at lower altitudes, in an area around Castro- trovillari, is Mediterranean pluvioseasonal-oceanic with a villari and nearby towns, in the province of Cosenza (Fig. meso-Mediterranean thermotype and a subhumid ombro- 1). This area has been widely surveyed for both fl ora and type (Fig. 2, Tab. 1). The bioclimatic indexes (Rivas-Marti- fauna (i.e., Terraciano 1890, Gavioli 1936, Bernardo and nez 2008, without compensation for the altitude) were cal- Maiorca 1996, Brandmayr et al. 2002, Bernardo et al. 2011) culated on the basis of thermo-pluviometric data available whereas, despite its importance, it has not been studied on the institutional web sites of ARPA-Calabria (http:// from a phytosociological standpoint nor has its vegetation www.cfd.calabria.it/) and Protezione Civile-Apulia (http:// been compared to other S. austroitalica associations. It is www.protezionecivile.puglia.it/). worth mentioning that these phytocoenoses are also partial- ly included within the Pollino National Park and the pro- posed Site of Community Importance ‘La Petrosa’. Thus, the aim of this study is threefold: 1) to describe and characterise the plant communities dominated by S. austroitalica in the southern side of the Pollino Massif; 2) to analyse their fl oristic and chorological relationships with other S. austroitalica grasslands; 3) to discuss their syntax- onomy in the context of Italian and south European Medi- terranean grasslands. Fig. 2. Ecological climate diagram for Castrovillari, in the prov- ince of Cosenza (Italy). The dashed line indicates mean monthly temperature (°C); the solid line indicates mean monthly precipita- tion (mm). Vegetation analysis Fig. 1. (A) Map of the south of Italy displaying the mountain range of Murge, Gargano and Pollino. (B) South-eastern part of Rocky pastures dominated by Stipa austroitalica in the the National Park of Pollino (shaded area). The study area is indi- area surrounding Castrovillari and nearby towns (Fig. 1) cated by vertical lines. were sampled by 16 phytosociological relevés, according to the standard method of the Zürich–Montpellier school (Braun-Blanquet 1932, Westhoff and Van der Maarel 1978). Material and methods We sampled plant communities with S. austroitalica occur- ring with cover values greater than 30% (i.e., 3, 4 or 5 on Study area the Braun-Blanquet abundance-dominance scale). The plot The Pollino Massif is located on the border between the sizes ranged between 70–100 m2, which is nearly equal to Regions of Calabria and Basilicata, in the south of Italy. Its the mean plot size calculated for the Hippocrepido-Stipion main peaks, Pollino Mountain (2248 m) and Serra Dolce- (see below). The altitudinal range was between 430 and 700 dorme (2267 m), are the highest in southern Italy (Fig. 1). m asl. Moreover, to take into account the altitudinal varia- The core area of the massif is made of limestone and dolo- tions of grassland vegetation, three additional relevés were mitic rocks, cut by faults and deep gorges. In the Calabrian carried out near Campotenese at nearly 1000 m asl where S. side, around the towns of Castrovillari and Frascineto, the austroitalica is replaced by Stipa dasyvaginata Marti- relief degrades south- and eastwards to the Sibari Plain and novský subsp. apenninicola Martinovský et Moraldo (On- the Ionian Sea, roughly following the route of the Coscile, line Suppl. Tab. 1, On-line Suppl. Appendix 1). 90 ACTA BOT. CROAT. 75 (1), 2016 HIPPOCREPIDO-STIPION IN THE POLLINO MASSIF (ITALY) Tab. 1. Bioclimate of stations representative of some Stipa austroitalica associations. Alt. – altituide; Me.po – Mediterranean pluviosea- sonal oceanic; Te.oc/sm – temperate oceanic, submediterranean variant; Te (%) – percentage of temperate (hydrologic) years in the time range, Me (%) – percentage of Mediterranean (hydrologic) years; mme – mesomediterranean; tme – thermomediterranean; mte – meso- temperate; sme – supramediterranean; sec – dry; shu – subhumid;