Revision of the central Mediterranean xerothermic cliff vegetation

01 Pubblicazione su rivista
Terzi Massimo, Jasprica Nenad, Cakovic Danka, DI PIETRO Romeo
ISSN: 1654-109X

Questions: What are the syntaxonomic and synchorological patterns of the xerothermic
chasmophytic vegetation in the central part of the Mediterranean Basin?
What are the diagnostic species of the high-rank
syntaxa of Asplenietalia glandulosi,
Onosmetalia frutescentis and Centaureo dalmaticae-Campanuletalia pyramidalis?
Location: Mediterranean coastal and subcoastal areas of southern France, Italy,
Malta, Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Albania and of mainland
Greece.
Methods: The data set of 1,261 published relevés was analysed using hierarchical
clustering (Flexible Beta method), involving a series of data transformations. Indicator
species analysis was used to select the best dendrogram solution and identify diagnostic
taxa of the main clusters. The dendrogram was interpreted from a syntaxonomic
point of view, using nomenclatural type relevés as a basis. The NMDS
ordination was performed in order to visualize the floristic relationships among associations
and high-rank
syntaxa. MRPP was used to test for differences among
alliances.
Results: The classification revealed four main clusters of relevés representing the
chasmophytic vegetation of southern France, Sardinia and the northwestern part of
Italy (Asplenienalia glandulosi/Asplenietalia glandulosi), the southwestern part of Italy
and Malta (Tinguarrenalia siculae/Asplenietalia glandulosi), the Adriatic Basin area
(Centaureo dalmaticae-Campanuletalia pyramidalis) and the southern Balkans
(Onosmetalia frutescentis). The NMDS ordination confirmed the overall pattern, while
MRPP showed significant differences among the alliances of the above-mentioned
orders and suborders. The lists of diagnostic taxa of the high-rank
syntaxa were revised
according to a supra-national
perspective.
Conclusions: The new syntaxonomic scheme provides a comprehensive overview of
the chasmophytic vegetation of the central part of the Mediterranean Basin. This
scheme mostly matches the recently published EuroVegChecklist, but also exhibits
important novelties concerning the syntaxonomic position of some alliances
(Dianthion rupicolae, Centaureion pentadactyli, Arenarion bertolonii and Caro-Aurinion),
and the floristic and chorological relationships among high-rank
syntaxa, with new
revised sets of diagnostic taxa. This revision might be useful for further small-scale
phytosociological studies.

© Università degli Studi di Roma "La Sapienza" - Piazzale Aldo Moro 5, 00185 Roma