The Festuco-Brometea Grasslands on Sandstone and Marl-Clay-Sandstone Substrata in Tuscany (Northern-Central Italy)

摘要: The grasslands dominated by Bromus erectus and/or Brachypodium rupestre cover large areas on sandstone and marl-clay-sandstone substrata (limestone is excluded), of the Apennines pre-Apennines between Pistoia Arezzo provinces (Tuscany, Central Italy). Our investigation was focused to 71 unpublished releves 45 literature from Tuscany surrounding areas, reporting original Astragalo monspessulani-Brometum erecti, Centaureo bracteatae-Brometum erecti Ononido masquillerii-Brometum erecti. The were submitted exploratory multivariate analysis, allowing detect nine distinct groups. Their consistence verified mean NMDS against Ellenberg/Pignatti indicator values, CCA constrained chorotypes growth forms. Diagnostic species definitive groups resulting analysis chosen according fidelity, based φ coefficient association. splits data set in two main subclusters; first one (A) includes few low altitude, thermophilous conenoses, interpreted as a transition submediterranean aspects Festuco-Brometea class and other Mediterranean herbaceous shrubby classes; second subcluster (B) most can be clearly subdivided pioneering, mesoxerophilous communities (B1 B2a groups) mesophilous (B2b group). clusters B1 are referred Coronillo minimae-Astragaletum monspessulanii association three groups: Plantago argentea-Carex caryophyllea communities, Tragopogon samaritani-Bromus Festuco trachyphyllae-Brometum ass. nova. group (B2b) releves, together with slightly differentiated community; due non-relevant differences these grassland types floristic, ecological chorological perspectives, we propose herewith treat them subassociations (typicum, ononidetosum masquillerii linetosum cathartici). Post-cultural human-disturbed also detected. All attributed Polygalo mediterraneae-Bromenion suballiance (Bromion alliance), even if clear subdivision pioneer more mesophilous evolved ones noted.